• Proxmox Breaks Storage/LVM Backing If Killing QEMU-IMG

    I tried to stop a qemu-img copy or clone and it broke everything. It was fine to "stop" it from the GUI but a process still persisted so I killed the relevant qemu-img and the kernel went crazy. It also may not have helped that I tried to lvremove a different volume (an unused disk). But either way it breaks LVM (you cannot even run lvdisplay) so a reboot is necessary. Jan 17 06:45:21 testserver kernel: [ 5680.439337] systemd-udevd D 0&nbs........
  • systemd management using systemctl and journalctl to check systemd logs

    systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system. The key commands or arguments you will use with systemctl are the following: Unit Commands: list-units [PATTERN...] List loaded units &nbs........
  • Linux Mint USB Kernel Tainted and Locked Port/Dev File

    Essentially a program I was running for mining did not terminate properly with Ctrl+C it is listed as defunct and cannot be killed, kernel is tainted and normal tricks to disable the port are impossible the dev and sys entries for the device cannot be browsed or interacted with in any form without a lockup of the request. The only solution is to reboot due to the kernel taint as far as I can find so far. [1130246.811056] INFO: task minerd:21861 blocked for more th........
  • USB 3.0 External HDD Enclosure Seagate UAS problems - [sdd] tag#1 CDB: Write(16) 8a 00 00 00 00 01 70 04 08 68 00 00 00 08 00 00

    This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver. The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether. Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
  • mdadm frozen and doesn't realize array is dead/missing failed due to unplugged drives

    This was a surprising bug but I unplugged all drives for an array md127. At first it was just 1 drive and mdadm seemed to notice this. I unplugged the second drive taking the array offline but mdadm did not realize it was offline and still showed a non-existent disk as being part of it. This created problems trying to unmount it or even to stop this array with mdadm freezing. As for how to fix it I can only think of making sure you are not in a mounted path of........
  • MySQLD Server shutdown remotely unexpectedly

    170110 5:35:23 [Note] /usr/libexec/mysqld: Normal shutdown 170110 5:35:23 [Note] Event Scheduler: Purging the queue. 0 events 170110 5:35:23 InnoDB: Starting shutdown... 170110 5:35:24 InnoDB: Shutdown completed; log sequence number 0 12765401 170110 5:35:24 [Note] /usr/libexec/mysqld: Shutdown complete 170110 05:35:24 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended........
  • fdisk wq causes hung process

    I created a new partition table on a newly plugged in device and it caused fdisk to hang (even force kill does not work). It also may be a bad drive or some other issue because fdisk -l hangs after the first 2 HDDs (totaly of 8 HDDs on this system): [1232879.903596] INFO: task fdisk:27176 blocked for more than 120 seconds. [1232879.903607] Tainted: P&nbs........
  • blocked for more than 120 seconds issues with iowait and timeout on Live Linux distribution while writing to physical disk

    This happened while an mdadm array was syncing, all access from writing a new blank file to opening a small .txt file was very slow: [222117.312078] kjournald starting. Commit interval 5 seconds [222117.685060] EXT3-fs (md0): using internal journal [222117.685096] EXT3-fs (md0): mounted filesystem with ordered data mode [222122.376847] kjournald starting. Commit interval 5 seconds [222122.602825] EXT3-fs (md2): using internal jour........
  • drbd won't sync 8.3.13 on OpenVZ kernel

    I used the matching 8.3.13 utilities and it didn't work but strangely the newer 8.3.16 which makes DRBD complain works just fine. GIT-hash: 83ca112086600faacab2f157bc5a9324f7bd7f77 build by root@sighted, 2012-10-09 12:47:51  0: cs:SyncSource ro:Secondary/Primary ds:UpToDate/Inconsistent A r-----     ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5236960   &am........
  • Linux Ubuntu Nvidia GT430 Lockups/Errors/Freezes NVRM: os_schedule: Attempted to yield the CPU while in atomic or interrupt context

    I'm running Ubuntu 10.10 with Asus NVIDIA GT430 2.6.35-32-generic-pae #65-Ubuntu SMP Tue Jan 24 14:06:16 UTC 2012 i686 GNU/Linux Nvidia binary driver: 260.19.06 The screen sometimes completely freezes and locks up or everything starts going very slow: [1903398.100007] NVRM: os_schedule: Attempted to yield the CPU while in atomic or interrupt context [1903402.373210] NVRM: Xid (0001:00): 53, CMDre 00000000 00000080 00000000 00000005 00........
  • Linux High IOWAIT updatedb can't be killed and crash with mdadm

    high IO wait 424 root 39 19 1900 848 552 D 0.0 0.0 0:00.91 updatedb root 424 0.0 0.0 1900 848 ? DN Mar11 0:00 /usr/bin/updatedb -f sysfs?rootfs?bdev?proc?cpuset?binfmt_misc?debugfs?sockfs?usbfs?pipefs?anon_inodefs?futexfs?tmpfs?inotifyfs?eventp........
  • updatedb/mdadm caused a kernel panic?

    Jan 16 04:02:03 centosbox syslogd 1.4.1: restart. Jan 16 04:07:34 centosbox kernel: INFO: task updatedb:20771 blocked for more than 300 seconds. Jan 16 04:07:34 centosbox kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jan 16 04:07:34 centosbox kernel: updatedb D F78BE050 6476 20771 20766&n........
  • md: data-check of RAID array md3

    This really made me nervous but notice the mdstat says "check". This is because in Ubuntu there is a scheduled mdadm cronscript that runs everyday on Sunday at 00:57 that checks your entire array. This is a good way because it prevents gradual but unnoticed data corruption which Inever thought of. As long as the check completes properly you have peace of mind knowing that your data integretiy is assured and that your hard drives are functioning properly (I'........
  • Linux Kernel Freeze/Hang during boot on io scheduler cfq registered (default)

    You'll see the following and the boot process will freeze: io scheduler noop registered io scheduler anticipatory registered io scheduler deadline registered io scheduler cfq registered (default) I have struggled with this issue on vari........
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