| Am I using Cron / Crontab Correctly in Pop_OS! / Ubuntu? Posted: 27 Nov 2021 05:51 PM PST I'm attempting to use dwall (Dynamic Wallpaper) with cron to schedule an hourly wallpaper change on Pop!_OS 21.04, but for whatever reason cron.service isn't executing my crontab file (comment lines excluded): 0 * * * * env PATH=/home/m/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin DISPLAY=:1 DESKTOP_SESSION=pop DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/1000/bus" /usr/bin/dwall -p -s beach
When I check to see if cron.service is running (systemctl status cron.service), this is the output I get: cron.service - Regular background program processing daemon Loaded: loaded (/lib/systemd/system/cron.service; enabled; vendor preset: enabled) Active: active (running) since Sat 2021-11-27 17:34:26 EST; 3h 6min ago Docs: man:cron(8) Main PID: 980 (cron) Tasks: 1 (limit: 38305) Memory: 17.4M CGroup: /system.slice/cron.service └─980 /usr/sbin/cron -f -P
I confirmed that dwall is working as expected via terminal using either /usr/bin/dwall -p -s beach or dwall -p -s beach |
| When storing text on a USB drive, how do I make cat not hang? Posted: 27 Nov 2021 05:53 PM PST Warning: I used these commands on a drive that had nothing on it (/dev/sdb). Do not attempt this on a drive with anything important on it. I was experimenting some, and I discovered that the following works: $ printf 'hi\n' | sudo tee /dev/sdb hi $ sudo head -n 1 /dev/sdb hi $
Neat. Here's where I'm confused. I tried it again with cat (the first command is the same, I replaced the second one with sudo cat /dev/sdb. It printed hi, followed by a newline, and hung. Doing Ctrl + C didn't work to stop it. Bummer. I reasoned that perhaps cat wanted a null (\0) character at the end. So I tried again (printf 'hi\n\0' | sudo tee /dev/sdb), and head worked as before, but cat still hung. How can I get cat to not hang when writing directly to a USB drive? I'm not asking if this is a good idea (it isn't). I'm well aware I could just format the drive and use a text file, but I'm curious why this didn't work as expected. I'm using Debian 11, with a 2 GB flash drive (/dev/sdb). |
| Pop_OS Grub can't find Windows Posted: 27 Nov 2021 05:12 PM PST I know this question was answered before... But I'm so new that I don't even know how to do it :( After installing Linux and giving it a try i found that I coudn't boot back to windows and I was stuck in Linux...which isn't really bad, but I still need windows. I tried os-prober and boot-repair LSBLK command: AME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 119.2G 0 disk ├─sda1 8:1 0 499M 0 part ├─sda2 8:2 0 16M 0 part ├─sda3 8:3 0 118.2G 0 part /media/trollcraft1002/6EF006E2F006AFFF ├─sda4 8:4 0 565M 0 part └─sda5 8:5 0 1M 0 part sdb 8:16 0 465.8G 0 disk ├─sdb1 8:17 0 461.8G 0 part / └─sdb2 8:18 0 4G 0 part └─cryptswap 253:0 0 4G 0 crypt [SWAP] sdc 8:32 0 931.5G 0 disk └─sdc1 8:33 0 927.3G 0 part
SDA3 is the Windows location SDB is the Linux OS: POP_OS 21.04 WINDOWS 10: 20H2
sudo parted -l Model: ATA SAMSUNG SSD 830 (scsi) Disk /dev/sda: 128GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1049kB 524MB 523MB ntfs Basic data partition hidden, diag 2 524MB 541MB 16.8MB Microsoft reserved partition msftres 3 541MB 127GB 127GB ntfs Basic data partition msftdata 4 127GB 128GB 592MB ntfs hidden, diag 5 128GB 128GB 1049kB bios_grub Model: ATA Hitachi HDS72105 (scsi) Disk /dev/sdb: 500GB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 2097kB 496GB 496GB primary ext4 2 496GB 500GB 4295MB primary linux-swap(v1) Model: ATA ST1000DM003-1SB1 (scsi) Disk /dev/sdc: 1000GB Sector size (logical/physical): 512B/4096B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 16.8MB 996GB 996GB ntfs Basic data partition msftdata Model: Linux device-mapper (crypt) (dm) Disk /dev/mapper/cryptswap: 4294MB Sector size (logical/physical): 512B/512B Partition Table: loop Disk Flags: Number Start End Size File system Flags 1 0.00B 4294MB 4294MB linux-swap(v1)
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| Environment Variables defined in /etc/environment only show for root, not home user Posted: 27 Nov 2021 05:06 PM PST I'm fairly new to linux and am setting up a server running Ubuntu 20.04 LTS. I've defined a few environment variable in /etc/environment for use in my docker-compose.yml file. I added the variables to the /etc/environment file, formatted as shown below. PUID=XXXX PGID=XXX TZ="America/REGION" USERDIR="/home/USER_NAME"
However, it seems that only the root user, and not the home user can see these variables. When I use printenv as the home user these variables don't show up, however they do show up using sudo or as the root user. I thought that when a environment variable was defined in /etc/environment that it should be accessible to all users, but it seems that this isn't the case or that something is going wrong. This is causing problems when trying to access these environment variables in my docker-compose.yml file, as on startup it can't access these variables. I'm not sure how to get these variables to show up to users other than root. I'd appreciate any help! |
| Expose local dev server externally with SSH Tunneling / Port Forwarding through Raspberry Pi Posted: 27 Nov 2021 04:51 PM PST I'm trying to expose my local dev server externally so that my web app can be tested by users who are not in my local network. Users who test the web app must run the apps with localhost:3000 and localhost:8080 in their browsers, as those are white listed domains. I thought this would be a perfect application for my Raspberry Pi to act as a proxy using SSH tunneling. This is my setup: 
Local port forwarding (i.e. ssh -L) is working well, but I can't get remote port forwarding (i.e. ssh -R) to work. I'm not able to load localhost:3000 or localhost:8080 from either the Client or the Raspberry Pi. I even enabled GatewayPorts yes on my Raspberry Pi as instructed here: https://blog.trackets.com/2014/05/17/ssh-tunnel-local-and-remote-port-forwarding-explained-with-examples.html. The fact that those URLs won't load on my Raspberry Pi implies to me that this problem is between the Raspberry Pi and my Dev Server. How can I get this proxy working? |
| Pop OS 21.04 is randomly crashing everytime Posted: 27 Nov 2021 03:53 PM PST Everytime my Pop OS just freezes at a random time when I start my computer and do stuff |
| FreeBSD serial port lock files Posted: 27 Nov 2021 03:05 PM PST Does anyone know when in FreeBSD's boot process /dev/ttyu*.init and /dev/ttyu*.lock files are created? In other words, are they created by the OS within its boot process, or are they created when I try to configure and then open a /dev/ttyu* serial port? Note: I am using four serial ports on my machines (Nexcom 6100 and Nexcom 6210) as an instrumentation interface, not a terminal interface. FreeBSD 13.0-RELEASE-p4 amd64 Thanks! |
| Can I force Conda to use system packages when available? Posted: 27 Nov 2021 03:02 PM PST I am looking to tidy up the build and runtime environment requirements for a scientific software package that has been worked on by grad students over the last 10 years and now has a conda environment from hell. As part of overhauling the environment, I am interested in whether I can force conda to check for system packages first and use those so that I can use the system repositories and package manager to keep after all the routine stuff instead of having conda download duplicates of everything and keep after those updates as well. |
| Adding a VLAN-transparent bridge to Linux (Debian) Posted: 27 Nov 2021 03:21 PM PST On my current Debian system I use VLAN tagging and I create bridges br-wan and br-lan that I use for LXC containers: auto lo br-lan br-wan iface lo inet loopback iface br-wan inet manual bridge_ports eth0.3 bridge_maxwait 0 iface br-lan inet static address 192.168.200.10 netmask 255.255.255.0 gateway 192.168.200.1 bridge_ports eth0.2 bridge_maxwait 0 iface eth0.1 inet static address 10.7.1.10 netmask 255.255.255.0
Now I would like to add a KVM guest that gets transparent access to eth0 and in turn uses VLAN tagging internally (for example, to create a virtualized router routing between eth0.2 and eth0.3). To test, I did the following: brctl addbr br-master brctl addif eth0
And then I created a KVM guest with --network=bridge=br-master,model=virtio which creates an interface vnet0 that is also added as bridge port to br-master. Inside the guest added the VLAN interfaces. On the host, I see tagged packets in vnet0 (tcpdump -i vnet0 -e vlan) and br-master (tcpdump -i br-master -e vlan). However, the traffic never reaches eth0 on the host. I am sure the story is not that simple. How can I add such a VLAN-transparent "master bridge" to my system, without disrupting my old config? |
| Calcurse cant sync with Nextcloud Posted: 27 Nov 2021 01:31 PM PST Hello I've recently setup a nextcloud instance with a calendar and wanted to sync my calcurse with it. This is my calcurse-caldav config(password, username and hostname obviously changed): [General] Binary = calcurse Hostname = nextcloud.example.com/nextcloud Path = remote.php/dav/ AuthMethod = basic HTTPS = Yes DryRun = No Verbose = Yes [Auth] Username = BestUsername Password = SuperSecretPassword
I get the following error though: ╰─$ calcurse-caldav --init keep-remote Connecting to nextcloud.example.com/nextcloud... Removing all local calcurse objects... error: The server at nextcloud.example.com/nextcloud replied with HTTP status error: code 415 (Unsupported Media Type) while trying to access error: https://nextcloud.example.com/nextcloud/remote.php/dav/.
I strongly suspect that there is something wrong with my config but I can't understand what as this config worked perfectly with Calibre. |
| Restore removed files from LUKS-encrypted disk Posted: 27 Nov 2021 01:48 PM PST The problem I erroneously removed several files from my /home/username with rm. I realized the mistake as soon as I hit enter, but the damage was done. I immediately created a full disk image with sudo dd if=/dev/sda of=/media/username/external_drive/image.iso and copied it to another PC and prepared to follow a very long path towards data recovery. And then realized I had no idea about where to start from. What I did I read some guides online and eventually extundelete /dev/partition_to_recover_from --restore-directory /path/to/restore came up as the most promising solution, so I tried it. The first problem I encountered was that I had encrypted my drive with LUKS (during OS install) and had to decrypt it. After some more research, I prepared the partition with the following commands (here I changed the real volume group name from the real value of <my_pc_name>-vg to pc-vg). $ sudo kpartx -a -v image.iso # map the disk image partitions add map loop0p1 (254:0): 0 997376 linear 7:0 2048 add map loop0p2 (254:1): 0 2 linear 7:0 1001470 add map loop0p5 (254:2): 0 975769600 linear 7:0 1001472 $ sudo cryptsetup luksOpen /dev/mapper/loop0p5 img # unlock the partition with my data Enter passhprase for /dev/mapper/loop0p5: $ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:0 0 465,8G 0 loop ├─loop0p1 254:0 0 487M 0 part ├─loop0p2 254:1 0 1K 0 part └─loop0p5 254:2 0 465,3G 0 part └─img 254:3 0 465,3G 0 crypt ├─pc--vg-root 254:4 0 464,3G 0 lvm └─pc--vg-swap_1 254:5 0 980M 0 lvm [...omitting other lsblk output...] $ sudo vgchange -a y frdm-vg 2 logical volume(s) in volume group "pc-vg" now active
and then tried to recover with $ sudo extundelete /dev/mapper/pc--vg-root --restore-directory /home/username/path/to/restore NOTICE: Extended attributes are not restored. WARNING: EXT3_FEATURE_INCOMPAT_RECOVER is set. The partition should be unmounted to undelete any files without further data loss. If the partition is not currently mounted, this message indicates it was improperly unmounted, and you should run fsck before continuing. If you decide to continue, extundelete may overwrite some of the deleted files and make recovering those files impossible. You should unmount the file system and check it with fsck before using extundelete. Would you like to continue? (y/n)
However, the partition was not mounted and df confirmed that. Also, sudo fsck -N only wanted to operate on /dev/sdaX. In doubt, I rebooted the system and repeated the above steps. I received exactly the same output, and considering that I was working on a copy of the original disk image (so I had a backup to use in case of data loss) this time I answered y. The result was: $ sudo extundelete /dev/mapper/pc--vg-root --restore-directory /home/username/path/to/restore NOTICE: Extended attributes are not restored. WARNING: EXT3_FEATURE_INCOMPAT_RECOVER is set. The partition should be unmounted to undelete any files without further data loss. If the partition is not currently mounted, this message indicates it was improperly unmounted, and you should run fsck before continuing. If you decide to continue, extundelete may overwrite some of the deleted files and make recovering those files impossible. You should unmount the file system and check it with fsck before using extundelete. Would you like to continue? (y/n) y Loading filesystem metadata ... extundelete: Extended attribute has an invalid value length when trying to examine filesystem
I did do other research, but I couldn't understand what that means. The questions I'll try to avoid the XY problem. Is the method I used to try to recover my data corect? If so, what is extundelete complaining about and how can I resolve it? If not, how can I (try to) restore my data from the LUKS-encrypted disk in Debian? If any additional info is required, please ask for it. P. S.: «Restore from your recent backup you obviously have» is the correct answer, I know =). I do have a full backup of my home taken a couple of days before the data loss (not such a n00b), but I lost the product of more than twenty hours of work and I would like to have it back. |
| Failed when binding the blox,neo-6m driver to uart 1 on BeagleBoneBlack-wireless Posted: 27 Nov 2021 02:42 PM PST |
| elif not working Posted: 27 Nov 2021 02:31 PM PST I am running a cardano node wich includes an automint solution. Im rewriting a script and i got it working. But there is a problem with a particular part of the script. This part of the elif should check if there is a incoming transaction of 8000000 and check if there is a metadata file in the folders metadata3-1 metadata3. If the transaction of 8000000 is ok and there is a file in both folders it should go to the "then" part of the script if there is not a file in one of the folders or the transaction is higher or lower then it should go to the "else" part. For some reason its not doing that. Can somebody help me with that? elif [ ${utxo_balance} == 8000000 ] || [ $(ls "metadata3-1/" | wc -l) >= 1 ] || [ $(ls "metadata3/" | wc -l) >= 1 ] ; then ###1 NFT version 1+2### echo "Sending NFT..." >> $log numberCompleted=$(( numberCompleted+1 )) POLICYID=$(cardano-cli transaction policyid --script-file $scriptPath) metadata_file=$(ls metadata3/ | sort -R | tail -1) metadata_file2=$(ls metadata3-1/ | sort -R | tail -1) name=$(echo ${metadata_file} | awk '{ print substr( $0, 1, length($0)-5 ) }') name2=$(echo ${metadata_file2} | awk '{ print substr( $0, 1, length($0)-5 ) }') head -n -3 ./metadata3/${metadata_file} > ./metadata3/metatemp.json ; mv ./metadata3/metatemp.json ./metadata3/${metadata_file} tail -n +4 ./metadata3-1/${metadata_file2} > ./metadata3-1/metatemp2.json ; mv ./metadata3-1/metatemp2.json ./metadata3-1/${metadata_file2} cat ./tempfiles/policy.json ./metadata3/${metadata_file} ./tempfiles/komma.json ./metadata3-1/${metadata_file2} > ./tempfiles/meta.json amountToSendUser=2200000 amountToDonate=2800000 amountToSendProfit=3000000 currentSlot=$(cardano-cli query tip --mainnet | jq -r '.slot') cardano-cli transaction build-raw \ --fee 0 \ ${tx_in} \ --tx-out ${in_addr}+${amountToSendUser}+"1 $POLICYID.${name}"+"1 $POLICYID.${name2}" \ --tx-out ${profitAddr}+${amountToSendProfit} \ --tx-out ${donationAddr}+${amountToDonate} \ --mint="1 $POLICYID.${name}"+"1 $POLICYID.${name2}" \ --minting-script-file $scriptPath \ --metadata-json-file ./tempfiles/meta.json \ --invalid-hereafter $(( ${currentSlot} + 10000)) \ --out-file tx3.tmp >> $log fee=$(cardano-cli transaction calculate-min-fee \ --tx-body-file tx3.tmp \ --tx-in-count 1 \ --tx-out-count 3 \ --mainnet \ --witness-count 2 \ --byron-witness-count 0 \ --protocol-params-file protocol3.json | awk '{ print $1 }') >> $log fee=${fee%" Lovelace"} amountToSendUser=$((${amountToSendUser} - ${fee})) cardano-cli transaction build-raw \ --fee ${fee} \ ${tx_in} \ --tx-out ${in_addr}+${amountToSendUser}+"1 $POLICYID.${name}"+"1 $POLICYID.${name2}" \ --tx-out ${profitAddr}+${amountToSendProfit} \ --tx-out ${donationAddr}+${amountToDonate} \ --mint="1 $POLICYID.${name}"+"1 $POLICYID.${name2}" \ --minting-script-file $scriptPath \ --metadata-json-file ./tempfiles/meta.json \ --invalid-hereafter $(( ${currentSlot} + 10000)) \ --out-file tx3.raw >> $log cardano-cli transaction sign \ --signing-key-file $paymentSignKeyPath \ --signing-key-file $policySignKeyPath \ --tx-body-file tx3.raw \ --out-file tx3.signed \ --mainnet >> $log cardano-cli transaction submit --tx-file tx3.signed --mainnet >> $log rm ./metadata3/${metadata_file} rm ./metadata3-1/${metadata_file2} else echo ${utxo_balance} >> $log echo "Refund Initiated..." >> $log currentSlot=$(cardano-cli query tip --mainnet | jq -r '.slot') cardano-cli transaction build-raw \ --fee 0 \ ${tx_in} \ --tx-out ${in_addr}+${utxo_balance} \ --invalid-hereafter $(( ${currentSlot} + 1000)) \ --out-file tx3.tmp >> $log fee=$(cardano-cli transaction calculate-min-fee \ --tx-body-file tx3.tmp \ --tx-in-count 1 \ --tx-out-count 1 \ --mainnet \ --witness-count 1 \ --byron-witness-count 0 \ --protocol-params-file protocol3.json | awk '{ print $1 }') >> $log fee=${fee%" Lovelace"} amountToSendUser=$(( ${utxo_balance}-${fee} )) echo ${amountToSendUser} >> $log cardano-cli transaction build-raw \ --fee ${fee} \ ${tx_in} \ --tx-out ${in_addr}+${amountToSendUser} \ --invalid-hereafter $(( ${currentSlot} + 1000)) \ --out-file tx3.raw >> $log cardano-cli transaction sign \ --signing-key-file $paymentSignKeyPath \ --tx-body-file tx3.raw \ --out-file tx3.signed \ --mainnet >> $log cardano-cli transaction submit --tx-file tx3.signed --mainnet >> $log fi
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| Where can I find the source code of Voidlinux Posted: 27 Nov 2021 12:08 PM PST Why do I need to know where is the code source? I found a bug in the config file of the service named wpa_supplicant, when using some shell, like sh or zsh instead of bash for the root user $ cat /etc/passwd root:x:0:0:root:/root:/bin/zsh
this error is in this file : /etc/sv/wpa_supplicant/auto - Because in bash, we can find in two directories like that
for f in /etc/wpa_supplicant/wpa_supplicant-*.conf /etc/wpa_supplicant-*.conf ; do #.... done
but we can't do it in another shell - my
PR is changing this for-loop or adding bash shebang, but can't find `Void-Linux source in GitHub |
| SCHED_BATCH, SCHED_IDLE and SCHED_OTHER controversy Posted: 27 Nov 2021 12:38 PM PST There are several scheduling options in Linux, which can be set to a process with the help of a chrt command line. And I can't seem to grasp one of them... SCHED_FIFO and SCHED_RR are basically real-time scheduling policies, with slight differences, no questions here mostly, they are always run first before any other processes.
SCHED_OTHER is the default policy, relying on nice values of per process to assign priorities.
SCHED_DEADLINE - I haven't completely understood this one, it seems to be actually closer to SCHED_FIFO but with set timers of execution, and may actually preempt SCHED_FIFO/SCHED_RR tasks if those timers are reached.
SCHED_IDLE - basically "schedule only if otherwise the CPU would be idling`, no questions here.
And now, there is SCHED_BATCH, which I found out that is quite controversial. On one hand, in the original implementations notes back from 2002 it is said it's basically the same as SCHED_IDLE for user code and SCHED_OTHER for kernel code (to avoid kernel resources lock-up due to a process never being scheduled). In the MAN articles though it is said it's basically the same as SCHED_OTHER but with a small penalty because it is considered CPU-bound. Now, theese two SCHED_BATCH explanations are not coherent one with another. Which one is the truth? Did SCHED_BATCH got reimplemented somewhere along the way? Or someone misunderstood SCHED_BATCH when was writing the MAN article? Which of the explanations is the true one? |
| No internet access on Arch fresh install Posted: 27 Nov 2021 01:16 PM PST I just freshly installed Arch on an ROG Asus laptop and successfully got everything setup. I was able to connect to the internet even after rebooting out of the live environment. I installed a few packages(git, vim etc, etc). I then went to install xfce and found that I was no longer connected to the WiFi(this laptop does not have an Ethernet port). I am not completely unable to connect to the internet as everything results in a Name or Service unknown error. I have restarted dhcpcd, resolvd and reboot several times to no effect. The interface still shows up in ip link and lspci -k as well as in iwctl. I am at a loss of what else to do and any help would be appreciated. |
| running bash script in systemd Posted: 27 Nov 2021 01:31 PM PST I'm trying to start a service which runs this script, which is just flags for a binary file This is the script: ./geth_linux --config ./config.toml --datadir ./mainnet --cache 100000 \ --rpc.allow-unprotected-txs --txlookuplimit 0 --http --ws \ --maxpeers 100 --syncmode=snap --snapshot=false --diffsync
When I run this script in terminal from the binary's directory /home/bsc, it runs as I want it to. When I start the service though, I get this error: (code=exited, status=203/EXEC)
Here is my .service file: [Unit] Description=BSC Full Node [Service] User=bsc Type=simple WorkingDirectory=/home/bsc ExecStart=/home/bsc/start.sh Restart=on-failure RestartSec=5 [Install] WantedBy=default.target
I have made this script executable with: chmod +x /home/bsc/start.sh
Also i have run: chown +R bsc.bsc /home/bsc/*
I also tried running ExecStart=/bin/bash /home/bsc/start.sh and also adding #!/bin/bash at the top line of the script but failed also. I'm stumped. Ubuntu 20.04.3 LTS systemd error log Nov 24 04:25:14 rezonautik systemd[1]: Started BSC Full Node. Nov 24 04:25:14 rezonautik bash[26939]: /home/bsc/start.sh: line 1: geth: command not found Nov 24 04:25:14 rezonautik systemd[1]: bsc.service: Main process exited, code=exited, status=127/n/a Nov 24 04:25:14 rezonautik systemd[1]: bsc.service: Failed with result 'exit-code'. Nov 24 04:25:19 rezonautik systemd[1]: bsc.service: Scheduled restart job, restart counter is at 1. Nov 24 04:25:19 rezonautik systemd[1]: Stopped BSC Full Node. Nov 24 04:25:19 rezonautik systemd[1]: Started BSC Full Node. Nov 24 04:25:19 rezonautik bash[26981]: /home/bsc/start.sh: line 1: geth: command not found Nov 24 04:25:19 rezonautik systemd[1]: bsc.service: Main process exited, code=exited, status=127/n/a
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| How delete BILLIONS of files efficiently on linux? Posted: 27 Nov 2021 05:12 PM PST A storage system had collected 1.7 billion files from revision backups over a couple of years and was getting a bit full. So I started to delete all files older than five years. Which I assume are around 1.7 billion (!!!) files with around 90 TByte of data - I have to estimate because even a mere find or du would take weeks, maybe months. The Backend (mdraid, ext4) itself actually isn't too important because I would like to change it anyway. I let rm delete files for one day and only got rid of around 0,1% of all files. I estimate that deleting everything that way would take one to two years. And most likely kill some drives while doing so. Not that I worry too much, it is a Hotswap RAID. I have been using ionice -c3 to make sure files are only deleted while the drives are not busy to avoid disk thrashing as the drive usually is under heavy load for 1-2 hours per day. On a rather funny sidenote, when I tried to run rm the first times the millions of hard links drove its memory usuage to around 100GByte then it coredumped. So I split the operation into smaller parts, works file if I only delete single subdirectories but still often spikes at 20-30GByte. My two questions: - how do I delete the old files on this system in a way that doesn't take years?
e.g. I thought about manually editing the Inode-Structures so the files are gone but the space isn't given back and then let fsck repair the system. other mad ideas are welcome. I can always get back by making an LVM snapshot. - what setups are there to avoid the same problem in the future? Eg. using a different file system, different tool chain, putting meta data (Inodes, allocation tables etcpp) on SSD - the data itself needs to stay on HD for several reason.
If noone comes up with a better idea I will just massively reduce the numbers of revisions created and/or tar/xz everything older than one month to an external USB drive. Which would be uncool because the users actually enjoy being able to access old stuff from the revisions. |
| Capture output of systemd-run --scope to journal Posted: 27 Nov 2021 05:42 PM PST For improved traceability, accountability, etc., I want certain applications to be supervised by systemd and have their output collected in the journal. I know that this all happens automatically when I use systemd-run's service mode, but due to dependence on the calling environment, this is sometimes not possible. I have tried using systemd-run and systemd-cat together, but have found that it sadly fails to capture the unit metadata. I know I could theoretically dump the environment variables to a file with env before starting the process and then pass that as EnvironmentFile= to systemd-run, but that seems like a hack. It also fails if there is other data in the execution environment than variables that are needed, such as file descriptors, although that's a relatively rare requirement, as shell pipes, the most common type of shared file descriptor, can usually be replaced with temporary named pipes or files. I'm not unwilling to use the hacky approach; I'm just wondering if there is a "known good" alternative to it. EDIT: Since the comments asked, the metadata fields I'm looking for are _SYSTEMD_UNIT, _SYSTEMD_SLICE, etc., as well as _AUDIT_LOGINUID, _CAP_EFFECTIVE, and other such metadata that is usually collected for supervised processes. I found out this is possible for scope units when I was looking at podman/conmon container logs, which have full metadata, despite being manually created using sd_journal_sendv from within a scope unit. I also checked the source code of logger(1) and it uses the same function, so I'm assuming there's something about the unit setup of podman/conmon that enables journald to establish the correlation that isn't there with systemd-run. |
| Network Manager Access Point WPS Pin Disable Posted: 27 Nov 2021 02:12 PM PST we are opening an Access Point with network manager (on a RPI4 with Raspbian) and everything is working fine except that when connecting from Windows 10 we are asked for a pin first (probably wps pin) instead of getting shown directly the passphrase field to enter. This is not observed on Mac and Linux. Our wifi-ap configuration: sudo nmcli c add con-name wifi-ap type wifi ssid test ifname wlan0 save yes autoconnect yes 802-11-wireless.mode ap 802-11-wireless.band bg ipv4.method shared wifi-sec.key-mgmt wpa-psk wifi-sec.psk "test1234"
We already tried multiple configurations from the provided page: https://developer.gnome.org/NetworkManager/stable/settings-802-11-wireless-security.html like: - wps-method 1
- proto rsn
- pairwise ccmp
But nothing really helped. Would be fantastic to get your support here. Thanks |
| Does lubuntu have an anti-blue light feature? Posted: 27 Nov 2021 01:50 PM PST |
| Linux shell script to check if another user has unread mail Posted: 27 Nov 2021 01:05 PM PST I'm looking to create a shell script that will accept userids as an argument to check if that user has unread mail in /var/spool/mail. How would I even go about checking a user's mail status? Is /var/spool/mail only unread mail? If so, then I'm assuming I would just check for users with files of size greater than 0. |
| Unable to use Valgrind on executable file for ARM-Linux Posted: 27 Nov 2021 02:00 PM PST I'm having problem using Valgrind on "arm-linux" executable file. I downloaded Valgrind from the main page here : http://valgrind.org/downloads/. Run the following command to install it: sudo ./configure sudo make sudo make install
On Ubuntu, I try with an executable HelloWorld file compiled "HelloWorld.c" using Linux GCC. Valgrind runs without any problem. Then I try it on an executable file compiled from using Cross-compiler for ARM-Linux (this executable file is compiled to run on an embedded device) and I got this error: valgrind: failed to start tool 'memcheck' for platform 'arm-linux': No such file or directory
I have digged around on google and couldn't find much information, I tried: export VALGRIND_LIB=/usr/local/lib/Valgrind
It still show the same error, what am I doing wrong? |
| How to preview my GRUB menu without rebooting? Posted: 27 Nov 2021 03:02 PM PST I want to change my default boot OS in GRUB2. But the only way I know of seeing the order of the OS I want in the GRUB menu is doing a reboot and seeing the menu displayed. In grub.cfg there are many more menuentry lines than actual choices in the GRUB menu, so I can't identify in that file the one I want. Is there any place where the actually displayed menu is stored so that I can see it without having to reboot? |
| Missing openvpn routes with network manager Posted: 27 Nov 2021 03:06 PM PST I'm trying to setup a VPN using network manager. When I run openvpn manually with my config, it works fine (sudo openvpn --config MyVPN.ovpn). Then when I print the routes (sudo route -n), it gives me: Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.254 0.0.0.0 UG 600 0 0 wlp3s0 10.c.d.0 172.a.b.1 255.255.255.0 UG 0 0 0 tun0 10.e.f.0 172.a.b.1 255.255.255.0 UG 0 0 0 tun0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlp3s0 172.a.b.0 0.0.0.0 255.255.255.0 U 0 0 0 tun0 192.168.1.0 0.0.0.0 255.255.255.0 U 600 0 0 wlp3s0
When I use network manager (with the openvpn plugin), I get am missing the 10. gateway routes. I checked Use this connection only for resources on its network for both ipv4 and 6 (I don't want all my traffic to go through that VPN). Why am I missing routes with network manager? I'm using Linux Mint 18.2, network manager 1.2.6-0ubuntu0.16.04.1 and openvpn 2.3.10-1ubuntu2.1 Here's my tail -f /var/log/syslog when i'm using NM: Sep 6 12:32:05 MyMint NetworkManager[867]: <info> [1504693925.1089] audit: op="connection-activate" uuid="d4e40650-bc76-4139-a92f-ab51276287e2" name="MyVPN" pid=15515 uid=1000 result="success" Sep 6 12:32:05 MyMint NetworkManager[867]: <info> [1504693925.1171] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",0]: Started the VPN service, PID 31326 Sep 6 12:32:05 MyMint NetworkManager[867]: <info> [1504693925.1314] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",0]: Saw the service appear; activating connection Sep 6 12:32:12 MyMint NetworkManager[867]: <info> [1504693932.3783] keyfile: update /etc/NetworkManager/system-connections/MyVPN (d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN") Sep 6 12:32:12 MyMint NetworkManager[867]: nm-openvpn-Message: openvpn[31341] started Sep 6 12:32:12 MyMint NetworkManager[867]: <info> [1504693932.3865] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",0]: VPN plugin: state changed: starting (3) Sep 6 12:32:12 MyMint NetworkManager[867]: <info> [1504693932.3866] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",0]: VPN connection: (ConnectInteractive) reply received Sep 6 12:32:12 MyMint nm-openvpn[31341]: OpenVPN 2.3.10 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [EPOLL] [PKCS11] [MH] [IPv6] built on Jun 22 2017 Sep 6 12:32:12 MyMint nm-openvpn[31341]: library versions: OpenSSL 1.0.2g 1 Mar 2016, LZO 2.08 Sep 6 12:32:12 MyMint nm-openvpn[31341]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts Sep 6 12:32:12 MyMint nm-openvpn[31341]: WARNING: file '/home/laurian/MyVPN/MyVPN.key' is group or others accessible Sep 6 12:32:12 MyMint nm-openvpn[31341]: NOTE: chroot will be delayed because of --client, --pull, or --up-delay Sep 6 12:32:12 MyMint nm-openvpn[31341]: NOTE: UID/GID downgrade will be delayed because of --client, --pull, or --up-delay Sep 6 12:32:12 MyMint nm-openvpn[31341]: UDPv4 link local: [undef] Sep 6 12:32:12 MyMint nm-openvpn[31341]: UDPv4 link remote: [AF_INET]170.75.241.82:1194 Sep 6 12:32:14 MyMint nm-openvpn[31341]: [MyVPN] Peer Connection Initiated with [AF_INET]170.75.241.82:1194 Sep 6 12:32:16 MyMint nm-openvpn[31341]: TUN/TAP device tun0 opened Sep 6 12:32:16 MyMint nm-openvpn[31341]: /usr/lib/NetworkManager/nm-openvpn-service-openvpn-helper --bus-name org.freedesktop.NetworkManager.openvpn.Connection_8 --tun -- tun0 1500 1558 172.a.b.4 255.255.255.0 init Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7477] manager: (tun0): new Tun device (/org/freedesktop/NetworkManager/Devices/8) Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7562] devices added (path: /sys/devices/virtual/net/tun0, iface: tun0) Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7562] device added (path: /sys/devices/virtual/net/tun0, iface: tun0): no ifupdown configuration found. Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7796] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",0]: VPN connection: (IP Config Get) reply received. Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7852] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: VPN connection: (IP4 Config Get) reply received Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7861] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: VPN Gateway: 170.x.y.z Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Tunnel Device: "tun0" Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: IPv4 configuration: Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Internal Gateway: 172.a.b.1 Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Internal Address: 172.a.b.4 Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Internal Prefix: 24 Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Internal Point-to-Point Address: 172.a.b.4 Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7862] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Maximum Segment Size (MSS): 0 Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7863] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Static Route: 10.c.d.0/24 Next Hop: 172.a.b.1 Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7863] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Static Route: 10.e.f.0/24 Next Hop: 172.a.b.1 Sep 6 12:32:16 MyMint nm-openvpn[31341]: chroot to '/var/lib/openvpn/chroot' and cd to '/' succeeded Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7863] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: Forbid Default Route: yes Sep 6 12:32:16 MyMint nm-openvpn[31341]: GID set to nm-openvpn Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7863] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: DNS Domain: '(none)' Sep 6 12:32:16 MyMint nm-openvpn[31341]: UID set to nm-openvpn Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7863] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: Data: No IPv6 configuration Sep 6 12:32:16 MyMint nm-openvpn[31341]: Initialization Sequence Completed Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7864] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: VPN plugin: state changed: started (4) Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7890] vpn-connection[0x1ba5460,d4e40650-bc76-4139-a92f-ab51276287e2,"MyVPN",9:(tun0)]: VPN connection: (IP Config Get) complete Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.7893] device (tun0): state change: unmanaged -> unavailable (reason 'connection-assumed') [10 20 41] Sep 6 12:32:16 MyMint dbus[823]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8035] keyfile: add connection in-memory (6cc36f83-a713-494f-a153-8c0ef8482c23,"tun0") Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8041] device (tun0): state change: unavailable -> disconnected (reason 'connection-assumed') [20 30 41] Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8061] device (tun0): Activation: starting connection 'tun0' (6cc36f83-a713-494f-a153-8c0ef8482c23) Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8070] device (tun0): state change: disconnected -> prepare (reason 'none') [30 40 0] Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8075] device (tun0): state change: prepare -> config (reason 'none') [40 50 0] Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8078] device (tun0): state change: config -> ip-config (reason 'none') [50 70 0] Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8081] device (tun0): state change: ip-config -> ip-check (reason 'none') [70 80 0] Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8088] device (tun0): state change: ip-check -> secondaries (reason 'none') [80 90 0] Sep 6 12:32:16 MyMint systemd[1]: Starting Network Manager Script Dispatcher Service... Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8132] device (tun0): state change: secondaries -> activated (reason 'none') [90 100 0] Sep 6 12:32:16 MyMint NetworkManager[867]: <info> [1504693936.8238] device (tun0): Activation: successful, device activated. Sep 6 12:32:16 MyMint dbus[823]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher' Sep 6 12:32:16 MyMint systemd[1]: Started Network Manager Script Dispatcher Service. Sep 6 12:32:16 MyMint nm-dispatcher: req:1 'vpn-up' [tun0]: new request (1 scripts) Sep 6 12:32:16 MyMint nm-dispatcher: req:1 'vpn-up' [tun0]: start running ordered scripts... Sep 6 12:32:16 MyMint nm-dispatcher: req:2 'up' [tun0]: new request (1 scripts) Sep 6 12:32:16 MyMint nm-dispatcher: req:2 'up' [tun0]: start running ordered scripts... Sep 6 12:32:16 MyMint ntpdate[31411]: the NTP socket is in use, exiting Sep 6 12:32:17 MyMint ntpdate[31471]: the NTP socket is in use, exiting Sep 6 12:32:17 MyMint ntpdate[31530]: the NTP socket is in use, exiting Sep 6 12:32:18 MyMint ntpd[1364]: Listen normally on 28 tun0 172.a.b.4:123 Sep 6 12:32:18 MyMint ntpd[1364]: Listen normally on 29 tun0 [fe80::a1e0:e276:5803:2ce5%9]:123 Sep 6 12:32:18 MyMint ntpd[1364]: new interface(s) found: waking up resolver
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| Trigger a script in another server Posted: 27 Nov 2021 05:03 PM PST I have a script which in turn triggers 4 more scripts in another server sequentially. My script is waiting until the first script completes in target server and then triggers the second one. Below is the code SCB_CMD=/sc/db2home/scbinst/bin/reload_scrpt1.sh SCB_LOG=/sc/db2home/scbinst/log/reload_scrpt1.log echo `date` "Executing $SCB_HOST:$SCB_CMD ..." ssh $SCB_HOST "$SCB_CMD | tee $SCB_LOG" RC=$? #--------------------------------------------------------------------------- # -- Check for errors #--------------------------------------------------------------------------- if [ $RC -ne 0 ] then echo `date` "!error occurred executing SCB load script1!" exit 99 fi #--------------------------------------------------------------------------- SCB_CMD=/sc/db2home/scbinst/bin/reload_scrpt2.sh SCB_LOG=/sc/db2home/scbinst/log/reload_scrpt2.log #--------------------------------------------------------------------------- # -- Execute the remote load script #--------------------------------------------------------------------------- echo `date` "Executing $SCB_HOST:$SCB_CMD ..." ssh $SCB_HOST "$SCB_CMD | tee $SCB_LOG" --------------------------------------------
Is there a way to trigger all these four scripts in parallel in target server? |
| File /etc/resolv.conf deleted on every reboot, why or what? Posted: 27 Nov 2021 04:26 PM PST I am having an issue where DHCP (I though as I read in other similar topics) is clearing the /etc/resolv.conf file on each boot. I am not sure about how to deal with this since the post I have found (1, 2 and some others) are for Debian based distros or other but not Fedora.
This is the output of ifcfg-enp0s31f6 so for sure is DHCP: cat /etc/sysconfig/network-scripts/ifcfg-enp0s31f6 HWADDR=C8:5B:76:1A:8E:55 TYPE=Ethernet DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=no IPV6_AUTOCONF=no IPV6_DEFROUTE=no IPV6_FAILURE_FATAL=no IPV6_ADDR_GEN_MODE=stable-privacy NAME=enp0s31f6 UUID=0af812a3-ac8e-32a0-887d-10884872d6c7 ONBOOT=yes IPV6_PEERDNS=no IPV6_PEERROUTES=no BOOTPROTO=dhcp PEERDNS=yes PEERROUTES=yes
In the other side I don't know if Network Manager is doing something else around this. Update: Content of NetworkManager.conf (I have removed the comments since are useless) $ cat /etc/NetworkManager/NetworkManager.conf [main] #plugins=ifcfg-rh,ibft dns=none [logging] #domains=ALL
Can I get some help with this? It's annonying be setting up the file once and once on every reboot. UPDATE 2 After a month I'm still having the same issue where file gets deleted by "something". Here is the steps I did follow in order to make a fresh test: - Reboot the PC
After PC gets restarted open a terminal and try to ping Google servers of course without success: $ ping google.com ping: google.com: Name or service not known
Check the network configuration were all seems to be fine: $ cat /etc/sysconfig/network-scripts/ifcfg-enp0s31f6 NAME=enp0s31f6 ONBOOT=yes HWADDR=C8:5B:76:1A:8E:55 MACADDR=C8:5B:76:1A:8E:55 UUID=0af812a3-ac8e-32a0-887d-10884872d6c7 BOOTPROTO=static PEERDNS=no DNS1=8.8.8.8 DNS2=8.8.4.4 DNS3=192.168.1.10 NM_CONTROLLED=yes IPADDR=192.168.1.66 NETMASK=255.255.255.0 BROADCAST=192.168.1.255 GATEWAY=192.168.1.1 TYPE=Ethernet DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=no
Restart the network service: $ sudo service network restart [sudo] password for <current_user>: Restarting network (via systemctl): [ OK ]
Try to ping Google servers again, with no success: $ ping google.com ping: google.com: Name or service not known
Check for file /etc/resolv.conf: $ cat /etc/resolv.conf cat: /etc/resolv.conf: No such file or directory
File doesn't exists anymore - and this is the problem something is deleting it on every reboot Create the file and add the content of DNS: $ sudo nano /etc/resolv.conf
Ping Google servers this time with success: $ ping google.com PING google.com (216.58.192.110) 56(84) bytes of data. 64 bytes from mia07s35-in-f110.1e100.net (216.58.192.110): icmp_seq=1 ttl=57 time=3.87 ms
Any ideas in what could be happening here? |
| behavior of ServerAliveInterval with ssh connection Posted: 27 Nov 2021 12:06 PM PST Using ssh I am logging to another system and executing scripts there that creates new machines, and do some setups. It takes around 7-8 hours. So what happened is, the ssh connection keeps dropping and I always get timeout with unsuccessful execution of the script. So now I am using this argument along with ssh connection: ssh -o ServerAliveInterval=60 user@host ....
This ssh is spawned multiple times. The problem is after few ssh connection, I am getting error : too many logins of user and the after ssh connections are getting closed just after successful logins.
So is it the behavior of the ServerAliveInterval, that keeps the ssh user login session in remote machine alive even after ssh work is over and that's why my further logins are disconnected? |
| Can I watch the progress of a `sync` operation? Posted: 27 Nov 2021 03:03 PM PST I've copied a large file to a USB disk mounted on a Linux system with async. This returns to a command prompt relatively quickly, but when I type sync, of course, it all has to go to disk, and that takes a long time. I understand that it's going to be slow, but is there somewhere where I can watch a counter go down to zero? Watching buffers in top doesn't help. |
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