Recently I brought my KVM host down for an upgrade. I shut down the guests within their OSes, confirmed they were powered off with a virsh list --all, and everything went well with the upgrade.
However, upon returning the guests to service, one of them would not start up. Typing virsh start I got the helpful error message
Error restoring domain: cannot send monitor command
Connection reset by peer
Why was this one VM broken but the others were fine?
I played around with virsh autostart and virsh autostart --disable but that had no effect, nor did a reboot of the hypervisor.
After some searching around, it turns out libvirt has the capability to keep "managed save states" of guests, kinda like a sleep mode or snapshot, to save you fully powering a guest OS off.
For some reason, a managed save for this one guest had been created, perhaps it had not shut down properly, or perhaps there's an errorr in libvirt. I could view the saved state with
# virsh list --all --managed-save
Id Name State
----------------------------------
- guest1 shut off
- guest2 saved
Now a virsh managedsave-remove guest2 returned it to the "shut off" state, and I could start it properly with virsh start as per usual.
Showing posts with label service. Show all posts
Showing posts with label service. Show all posts
Saturday, August 4, 2012
Saturday, April 21, 2012
starting rtorrent on system startup
rTorrent is a curses-based bittorrent client for Linux.
It's very light on system resources but has great features such as monitoring of a directory for .torrent files, auto-move based on status (incoming, seeding, complete, etc), categories, magnet link handling and RSS capabilities.
I have a headless system where I seed some (legal) torrents and wanted rTorrent to start up when the system did. There are some examples of init scripts on the rTorrent site but I didn't like how these ran, specifically the su constantly needing a password and the odd way it started GNU Screen.
Download
Installation
It's very light on system resources but has great features such as monitoring of a directory for .torrent files, auto-move based on status (incoming, seeding, complete, etc), categories, magnet link handling and RSS capabilities.
I have a headless system where I seed some (legal) torrents and wanted rTorrent to start up when the system did. There are some examples of init scripts on the rTorrent site but I didn't like how these ran, specifically the su constantly needing a password and the odd way it started GNU Screen.
Download
Installation
- Put it at /etc/init.d/bittorrent and make it executable
chmod +x /etc/init.d/bittorrent - Add to chkconfig
chkconfig --add bittorrent - Set to start on system startup
chkconfig bittorrent on - If you want non-root users to be able to control it, put this in your visudo, replace "username" with your non-priveledged username
username localhost=NOPASSWD:/etc/init.d/bittorrent* - Setup an alias to the script in the user's ~/.bashrc
alias bittorrent='/etc/init.d/bittorrent'
alias bt='bittorrent'
- CentOS 6 or Fedora 12-14. Probably also works on CentOS 5.
- screen and rtorrent
- A non-priveledged user to run rtorrent, this can either be a new user just to run torrents, or an existing user
- Absolute session path in the .rtorrent.rc file
session = /home/rtorrent/.session ## this is good
session = ~/.session ## this will break
session = .session ## so will this - Paths for other actions such as monitoring directories for .torrent files and auto-moving complete downloads don't have to be absolute.
- Control the daemon withbittorrent start, bittorent stop, bittorrent restart
- Get information about the daemon with
bittorrent status, bittorrent info - Connect to the screen session with
bittorrent connect
(press ctrl+a then d to disconnect)
- Released under GNU GPL v3 - http://www.gnu.org/licenses/
starting minecraft server on system startup
This is an initscript to run a Minecraft or CraftBukkit server on CentOS, Fedora, and Ubuntu.
Features
Distros using systemd (Fedora 15+, Arch Linux, etc) will not work.
Get the script, view Requirements, Installation, Backups, Multiple Instances, and Usage
License
Released under GNU GPL v3 - http://www.gnu.org/licenses/
Credits
Thanks to these people whose work I have used in the making of this
Features
- Start, stop, restart CraftBukkit as a system service
- Automatic (via cron) and manual logfile rotation
- Automatic (via cron) and manual backups
- Backup compression and rotation (keeps 7 days worth of backups)
- Check latest Recommended Build and update to it if required
- Information display including Java path, current memory usage, current TCP connections
- Able to run multiple separate instances of the server at once
- CentOS 6, CentOS 5, Fedora 14
(probably works on Fedora Core 6 and later, untested) - Ubuntu Server 12.04 LTS
Distros using systemd (Fedora 15+, Arch Linux, etc) will not work.
Get the script, view Requirements, Installation, Backups, Multiple Instances, and Usage
License
Released under GNU GPL v3 - http://www.gnu.org/licenses/
Credits
Thanks to these people whose work I have used in the making of this
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