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Any size limitation on the backing store?
by Jeff Brown 10 May '22

10 May '22

We have a few QCOW2 images that have grown rather large (> 250GB) and to back them up across the VLAN is resource intensive and time consuming. What I'd like to do to optimise backups is freeze the backing store and always run the VMs in 'snapshot 1', and then run 'snapshot 2' to backup 'snapshot 1' to reciprocal failover hypervisors in the DC. I do know it's common practice to even run multiple VMs off a single "golden image" backing store, but I'm concerned about the performance impact with such a large backing store, and 'snapshot 1' growing at ~10GB a year. With that in mind, it should be feasible to pivot 'snapshot 1' into the backing image periodically. Further, I am aware of incremental backups which Debian 11 doesn't yet support. I think it's coming in Debian 12, but some of our servers are actually still on Debian 10. jeff@abacus:/var/lib/libvirt/images$ virsh backup-begin dev error: Operation not supported: incremental backup is not supported yet In a nutshell, is it feasible to run off an > 250GB and growing backing store? Thanks in advance for any advice. -- Jeff Brown Future Foundation Cell 074 101 5170 VoIP 087 550 1210 Fax: 086 532 3508

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virtqemud high CPU load
by lejeczek 06 May '22

06 May '22

Hi guys, Anybody on centos9? With latest updates I get 100% load (so one core fully loaded) almost all the time, I don't remember that being the case before. 'virtqemud' itself does not log much, with default verbosity. Any thoughts? many thanks, L.

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Issue with Guest and 2 Displays
by Thomas Luening 30 Apr '22

30 Apr '22

Hi @ all Since switching from Debian 10 to Debian 11, I've had a new small unsolved problem... with essentially the same customizing as before. It all takes place on my local Desktop-PC, where I have set up a restricted VM for actions in the internet. After I started the VM locally on my PC, I can operate the VM with the virtviewer without any errors. If I then open the second monitor via the Menu 'View->Display', a blank white window appears with the message "Waiting for display 2". xrandr correctly shows the second display as disconnected and also all available display-modes. After the following command xrandr --output Virtual-2 --auto --right-of Virtual-1 both (!) displays are white and both are waiting for a display.... and nothing works anymore. A previously started SSH connection to the VM from the PC shows the following for this moment: tom@pc:~ $ ssh 192.168.100.10 $ tom@vm:~ $su- Password: root@vm:~ # journalctl -f Apr 29 16:24:34 internet kernel: [drm] driver is in bug mode Apr 29 16:24:44 internet spice-vdagent[809]: Unable to find a display id for output index 2) Apr 29 16:24:44 internet spice-vdagent[809]: Unable to find a display id for output index 3) Apr 29 16:24:44 internet spice-vdagent[809]: Unable to find a display id for output index 2) Apr 29 16:24:44 internet spice-vdagent[809]: Unable to find a display id for output index 3) Apr 29 16:24:44 internet kernel: input: spice vdagent tablet as /devices/virtual/input/input7 It is no longer possible to restart the VM via "systemctl reboot", the VM is probably stuck in some systemd-timeouts, only "systemctl reboot -ff" leads to a reboot as a hard intervention. Does anyone know this problem? Is there a solution for this, to get the second display working? Below some relevant system-informations of my PC and the VM. root@pc:~ $ lsb_release -a Distributor ID: Debian Description: Debian GNU/Linux 11 (bullseye) Release: 11 Codename: bullseye root@pc:~ # uname -a Linux pc 5.10.0-13-amd64 #1 SMP Debian 5.10.106-1 (2022-03-17) x86_64 GNU/Linux root@pc:~ # cat /etc/libvirt/qemu/internet.xml | grep '<video' -A 3 <video> <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='2' primary='yes'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> tom@vm:~ $ lsb_release -a Distributor ID: Debian Description: Debian GNU/Linux 11 (bullseye) Release: 11 Codename: bullseye tom@vm:~ $ dpkg -l | grep -i spice ii spice-vdagent 0.20.0-2 amd64 Spice agent for Linux tom@vm:~ $ systemctl status spice-vdagent.service ● spice-vdagentd.service - Agent daemon for Spice guests Loaded: loaded (/lib/systemd/system/spice-vdagentd.service; indirect; vendor preset: enabled) Active: active (running) since Fri 2022-04-29 16:00:56 CEST; 16min ago TriggeredBy: ● spice-vdagentd.socket Process: 847 ExecStart=/usr/sbin/spice-vdagentd $SPICE_VDAGENTD_EXTRA_ARGS (code=exited, status=0/SUCCESS) Main PID: 849 (spice-vdagentd) Tasks: 2 (limit: 4702) Memory: 944.0K CPU: 1.918s CGroup: /system.slice/spice-vdagentd.service └─849 /usr/sbin/spice-vdagentd Thanks and Best Regards Tom

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Re: how to change emulator path during live migration
by Peter Krempa 27 Apr '22

27 Apr '22

[re-adding libvirt-users list] Please always reply to the list so that the follow-up conversation is archived and delivered to all subscribers. On Wed, Apr 27, 2022 at 15:36:54 +0800, Jiatong Shen wrote: > Thank you for the feedback! > > Is it ok if the source node does not contain a emulator path used by the > dest node? for example, on src emulator path is /a/b/c, but > on dest it is /a/b/d, and /a/b/d does not exist on src. You can change the emulator path arbitrarily. The only limitation is that the emulator you pick (the binary, not the path) must be able to run the VM, but that will be validated during the migration.

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how to change emulator path during live migration
by Jiatong Shen 27 Apr '22

27 Apr '22

Hello libvirt experts, I am facing the following exceptions during live migrating a virtual machine from one compute node to another. file or directory: libvirt.libvirtError: Cannot check QEMU binary /usr/bin/kvm-spice: No such file or directory File "/var/lib/openstack/lib/python3.6/site-packages/eventlet/tpool.py", line 83, in tworker rv = meth(*args, **kwargs) File "/var/lib/openstack/lib/python3.6/site-packages/libvirt.py", line 1745, in migrateToURI3 if ret == -1: raise libvirtError ('virDomainMigrateToURI3() failed', dom=self) libvirt.libvirtError: Cannot check QEMU binary /usr/bin/kvm-spice: No such file or directory After some investigation, we found that this error is triggered because we do not have qemu-kvm installed in our container, btw the libvirt is directly installed on the source node. I have following questions Is it possible to change emulator during live migration? I try to to remove emulator under devices but looks like it does not help. thank you very much and looking forward for the feedback. -- Best Regards, Jiatong Shen

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set fixed time at vm guest startup?
by Fred Clift 27 Apr '22

27 Apr '22

I'm looking at the <clock> libvirt parameters. Is there a way to set the guests clock to a specific time/date at virt startup? I'm trying to virtualize a system with pci passthrough for a hardware device that wants to always live in pre-2011. The license manager for the software/hardware has 31-bit overflow of time calculations. The current process on the physical machine is to power it on, use the bios to set the hardware date to Jan 1 2010, boot the system, use an RC script to ntp-set the date now that the hardware is up and running, and then everything works till next boot. We even have a nice rc script that will set the clock back to 2010 if you do a clean shutdown/reboot. I see I can set my clock sync to variable and specify a negative offset - is there a way to just say "always be jan 10 2010 when you power on"? Fred

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discard option on ext4 mounts in QEMU qcow2 images
by Nate Collins 26 Apr '22

26 Apr '22

Hello, Does anyone have any real-world statistics on the reliability and performance of the ext4 discard option in QEMU VMs? I've heard it's discouraged for physical devices, as some are inefficient in how TRIM requests are processed, but I was wondering if there were any drawbacks/warnings when it comes to virtual disks (in this case, QCOW2s). I currently use either virtio-scsi or virtio-blk drivers for disk images depending on what the host/guest support, and run TRIMs weekly, but having an immediate freeing of space is desirable for many reasons. Also wondering if snapshots on snapshotting filesystems (such as ZFS) can run into corruption or other issues if snapshots are taken during a TRIM. Thanks.

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race condition? virsh migrate --copy-storage-all
by Valentijn Sessink 20 Apr '22

20 Apr '22

Hi list, I'm trying to migrate a few qemu virtual machines between two 1G ethernet connected hosts, with local storage only. I got endless "error: operation failed: migration of disk vda failed: Input/output error" errors and thought: something wrong with settings. However, then, suddenly: I succeeded without changing anything. And, hey: while ! time virsh migrate --live --persistent --undefinesource --copy-storage-all ubuntu20.04 qemu+ssh://duikboot/system; do a=$(( $a + 1 )); echo $a; done ... retried 8 times, but then: success. This smells like a race condition, doesn't it? A bit weird is the fact that the migration seems to succeed every time while copying from revolving disks to SSD; but the other way around has this Input/output error. There are some messages in /var/log/syslog, but not at the time of the failure, and no disk errors. These disks are LVM2 volumes and they live on raid arrays - and/so there is not a real, as in physical, I/O-error. Source system has SSD's, target system has regular disks. 1) is this the right mailing list? I'm not 100% sure. 2) how can I research this further? Spending hours on a "while / then" loop to try and retry live migration looks like a dull job for my poor computers ;-) Best regards, Valentijn

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Virtio-scsi and block mirroring
by Bjoern Teipel 20 Apr '22

20 Apr '22

Hello everyone, I’m looking at an issue where I do see guests freezing (Dl) process state during a block disk mirror from one storage to another storage (NFS) where the network stack of the guest can freeze for up to 10 seconds. Looking at the storage and IO I noticed good throughput ad low latency <3ms and I am having trouble to track down the source for the issue, as neither storage nor networking show issues. Interestingly when I do the same test with virtio-blk I do not really see the process freezes at the frequency or duration compared to virtio-scsi which seem to indicate a client side rather than storage side problem. I had looked at the syscalls and nothing stuck out: % time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 28.51 20.672654 8339 2479 ioctl 27.81 20.162714 3379 5967 31 futex 22.02 15.964498 785 20335 poll 15.22 11.038403 150 73561 io_submit 4.17 3.023285 41 73540 lseek 1.20 0.868003 5 158591 write 0.63 0.459030 11 42871 ppoll 0.22 0.159263 8 19314 recvmsg 0.16 0.115520 5 22526 read 0.04 0.029149 29149 1 restart_syscall 0.01 0.009252 28 330 sendmsg 0.00 0.001221 1221 1 munmap 0.00 0.000458 22 21 fcntl 0.00 0.000286 95 3 openat 0.00 0.000166 5 32 rt_sigprocmask 0.00 0.000103 10 10 fdatasync 0.00 0.000099 25 4 clone 0.00 0.000081 7 12 mmap 0.00 0.000077 19 4 close 0.00 0.000076 6 12 mprotect 0.00 0.000056 14 4 madvise 0.00 0.000025 6 4 set_robust_list 0.00 0.000023 6 4 prctl ------ ----------- ----------- --------- --------- ---------------- 100.00 72.504442 419626 31 total Does anyone have an idea how to better debug this issue ? Thanks Bjoern

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When does the balloon-change or control-error event occur
by Han Han 19 Apr '22

19 Apr '22

Hi developers, I have questions about balloon-change or control-error event: 1. What's the meaning of these events 2. When do the events occur? The comments of their callbacks don't mention that( https://gitlab.com/libvirt/libvirt/-/blob/master/include/libvirt/libvirt-do… https://gitlab.com/libvirt/libvirt/-/blob/master/include/libvirt/libvirt-do… )

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Help with libvirt
by Eduardo Kiassucumuca 19 Apr '22

19 Apr '22

Good morning I'm Eduardo, a computer science student and I'm doing a final course work focused on virtualization. The work consists of creating virtual machines on a server and allowing ssh access to the virtual machines that are on the server containing qemu/kvm/libvirt. The problem is that I can't access the virtual machines from an external network but I can access them inside the server. I would like to know what would be the best way since we want to have a single public ip and be able to have a reverse proxy to access the virtual machines, I would like to know from your experience what you recommend?

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Libvirt vs QEMU benefits
by M, Shivakumar 19 Apr '22

19 Apr '22

Hello, For one of our case validation, we were using direct QEMU commands before for VM creation as it was easier to configure the VMs. Inside VM we do run the real-time latency test. Recently we switched to libvirt for the VM creation and deletion. Surprisingly, we do see a significant increase in the real-time latency performance for the VMs launched through the libvirt. W.r.t configuration wise both VMs are the same, we just converted the existing QEMU commands into libvirt XMLs. I am wondering what and all the features which libvirt has, improving this performance. Thanks, Shivakumar M

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Libvirt Daemon Question
by Michael Espinoza 13 Apr '22

13 Apr '22

Hi I’ve been googling this for a bit with no luck. Is there a way of determining what mode an already running libvirt daemon is running in.(session or system) From the docs it sounded like it was determined by what user started the daemon. But in a test node I set up, I have libvirtd running as root yet I can still connect to both the session and system qemus with virsh. And if I were to want libvirtd only in session mode, how would I do that? Thanks for the help! This stuff is really awesome and I’m just trying to get a full understanding of it. -Mike -- Michael Espinoza Mobile Phone : 646 327 9273 Email : Mikespinoza(a)gmail.com

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"default" watchdog device - ?
by lejeczek 09 Apr '22

09 Apr '22

Hi guys. Without explicitly, manually using watchdog device for a VM, the VM (centOS 8 Stream 4.18.0-365.el8.x86_64) shows '/dev/watchdog' exists. To double check - 'dumpxml' does not show any such device - what kind of a 'watchdog' that is? watchdog-5.15-2.el8.x86_64 on such a VM does not seem to do anything with it. Host is centOS 9 with: qemu-img-6.2.0-11.el9.x86_64 libvirt-daemon-8.0.0-5.el9.x86_64 many thanks, L.

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Network interface element not working
by Ian Pilcher 06 Apr '22

06 Apr '22

I've added an interface element to a libvirt network, but it isn't working. The interface is not being added to the bridge, even after the system is rebooted. # virsh net-dumpxml ocp4-net <network> <name>ocp4-net</name> <uuid>b5852945-9889-4d22-ba61-879125316cec</uuid> <forward dev='eno2' mode='nat'> <nat> <port start='1024' end='65535'/> </nat> <interface dev='eno2'/> </forward> <bridge name='virbr-ocp4' stp='on' delay='0'/> <mac address='52:54:00:99:99:99'/> <ip address='192.168.123.1' netmask='255.255.255.0'> </ip> </network> # brctl show bridge name bridge id STP enabled interfaces virbr-ocp4 8000.525400999999 yes vnet0 virbr0 8000.525400a7ce7f yes virbr1 8000.52540051eb1f yes vnet1 # rpm -q libvirt libvirt-8.0.0-2.module_el8.6.0+1087+b42c8331.x86_64 Any ideas? -- ======================================================================== Google Where SkyNet meets Idiocracy ========================================================================

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Guest restarting after issuing a shutdown
by jonetsu 04 Apr '22

04 Apr '22

Hello everyone, I create kvm machines using a bash script. As expected from the script, the resulting virtual machines are performing as they should be. The aspect that I do not get is at the end of the creation, when issuing a 'shutdown now' in the guest and expecting that it will shut down. Instead it does shut down, but it is restarted immediately. The machines are created using an Arch Linux ISO file. The bash script runs in three stages, the first stage is on the host. virt-install will show the regular Arch Linux installation interface. The bash script is copied to the machine and its second stage is ran. After that a chroot is done and the third phase of the script is executed. When everything is configured and installed, here is what happens, commands are prefixed '%', text output is as is, and comments in '()' : guest : % shutdown now host : Domain creation completed. host : Restarting guest. (virt-manager shows the guest restarting) host : % virsh shutdown test02 (nothing happens, guest still shown) host : % virsh destroy test02 host : Domain test02 destroyed (guest display closes) What I'm expecting is that, when the 'shutdown now' is issued in the guest, that it will effectively terminate the guest, 'virsh list --all' will not show it running, and there'll be no need to issue a 'virsh destroy'. I have no clue at the moment why virsh is restarting the guest after a shutdown was issued in the guest. Looks like virsh did not get that it should terminate the guest and considers the shutdown as an error. Here are the versions involved : host : xubuntu 20.04 LTS libvirt 6.0.0-0ubuntu8.15 virt-manager 1:2.2.1-3ubuntu2.1 guest : archlinux 2022.03.01-x86_64 Thanks !

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Debugging hanging libvirt
by Tobias Hofmann (tohofman) 04 Apr '22

04 Apr '22

Hello all, I have a system with one VM running. After some time the VM needs to be temporarily stopped and started again. This start operation fails and from that point on any virsh command is hanging and does not execute. This issue is reproducible and I have already figured out that restarting libvirtd resolves this issue. However, I’m now trying to understand why it’s getting stuck in the first place. I try not to get too much into detail because I think this would be more confusing than it would actually help to understand the problem. In general, I’m wondering what approach you should follow to debug why libvirt gets stuck. Online I’ve read that you should run this command: `# gdb -batch -p $(pidof libvirtd) -ex 't a a bt f'`. I’ve run that command and attached the output to this mail. However, I have to admit that I have no idea what to do with it. System related info: * OS: CentOS 7.8.2003 * libvirt version: 4.5.0-33 Appreciate any help here! Thank you! Tobias

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Networking on macOS host, without TunTap
by Carl Winbäck 01 Apr '22

01 Apr '22

Dear libvirt users, I’m trying to get the following setup up and running: libvirt+qemu on a macOS Monterey host, with a Debian 11 guest. The domain type is hvf. The thing I’m struggling with now is how to configure networking in a sane way. Older articles reference the “TunTap” project, but AFAICT this software it is no longer recommended. Does anyone know of a good way to add networking to this setup without using TunTap? Best regards, Carl Winbäck

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Requirements to enable discard support on virtio-blk
by Andrew Martin 31 Mar '22

31 Mar '22

Hello, I am attempting to enable discard support on the virtio-blk device on a QEMU VM however it isn't working. My understanding is that this is enabled in QEMU >= 4.0, so I am not sure why this isn't working: Host OS: Ubuntu 20.04 (kernel 5.4.0) Guest OS: Ubuntu 18.04 (kernel 4.15.0) Guest config: <os> <type arch='x86_64' machine='pc-q35-4.2'>hvm</type> </os> <disk type='file' device='disk'> <driver name='qemu' type='qcow2' discard='unmap'/> <source file='/var/lib/libvirt/images/myvm.qcow2' index='1'/> <backingStore/> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/> </disk> What are the values for machine type that will support discard on virtio-blk? Anything 4.0 or greater (e.g. would pc-i440fx-4.0 work too)? I can see from the host's perspective that the guest appears to have discard enabled because the following command shows "discard = true": # virsh qemu-monitor-command myvm --hmp info qtree | grep discard yet inside the VM, even with the "discard" mount option set: # for f in /sys/block/vda/queue/discard_*; do echo $f; cat $f; done /sys/block/vda/queue/discard_granularity 0 /sys/block/vda/queue/discard_max_bytes 0 /sys/block/vda/queue/discard_max_hw_bytes 0 /sys/block/vda/queue/discard_zeroes_data 0 Are the virtio drivers in the guest kernel too old to support discard on virtio-blk? Or is something else missing? Thanks, Andrew

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virDomainCoreDump output format
by Shelly Kagan 29 Mar '22

29 Mar '22

Hi all, I have a small question regarding virDomainCoreDump. In the documentation[1] it is stated that the output is of format RAW. After implementing a function using this command the output file format that I see is ELF. I understand those formats are different, so is the documentation not updated? Is there a reason I will get an ELF format instead of RAW? Appreciate your help! [1] https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainCoreDumpWithF… -- Shelly Kagan Senior Software Engineer Red Hat <https://www.redhat.com> <https://www.redhat.com>

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PHP Warning: libvirt_domain_new(): Cannot get installation XML
by Benjamin Smith 29 Mar '22

29 Mar '22

Despite great success at using php-libvirt with other functions, I have been entirely unsuccessful in getting it to create a new domain/machine. Any time I do, and with virtually anything I try, I get the above error message. Running PHP 7.4 (remi) on otherwise stock AlmaLinux. *[root@sb4 html]# cat /etc/redhat-release AlmaLinux release 8.5 (Arctic Sphynx* *[root@sb4 html]# rpm -qa php php-fpm php-libvirt nginxphp-7.4.28-1.el8.remi.x86_64nginx-1.14.1-9.module_el8.3.0+2165+af250afe.alma.x86_64php-fpm-7.4.28-1.el8.remi.x86_64php-libvirt-0.5.5-1.el8.remi.7.4.x86_6412 XEON E312xx cores, 24 w/HT, 192GB RAM, etc. * When I run it, I find in php-fpm www.error-log: *[24-Mar-2022 20:05:51 UTC] PHP Warning: libvirt_domain_new(): Cannot get installation XML in /var/www/html/manage.php on line 190* Matching message onscreen: *Warning: libvirt_domain_new(): Cannot get installation XML in /var/www/html/manage.php on line 191* Here's the offending code: $networks = [ *'mac'* => '52:54:00:06:a7:df', *'network'* => 'default', *'model'* => *'e1000'*, ]; $disks = [ *'path'* => *"/var/lib/libvirt/images/myvm.qcow2"*, *'driver'* => *'qcow2'*, *'bus'* => *'ide'*, *'dev'* => *'hda'*, *'size'* => *'40G'*, *'flags'* => null, ]; error_reporting(-1); $result = libvirt_domain_new( $conn, 'myvm',* // name of the new domain* null,* // optional architecture string, can be NULL to get default (or false)* 2048,* // number of megabytes of RAM to be allocated for domain* 8192,* // maximum number of megabytes of RAM to be allocated for domain* 2,* // number of VCPUs to be allocated to domain* *'/var/www/html/AlmaLinux-8.4-x86_64-dvd.iso'*,* // installation ISO image for*$ $disks,* // array of disk devices for domain* $networks, null ); I've tried various values for $disks and $networks, setting error reporting to -1 (display anything and everything), journalctl -f on both the webserver and the virt host, etc but was never able to see any error other than this one. I've also been looking in the source code file for anything obvious, and I've been utterly unsuccessful in changing the error message. For example, inserting an invalid path for the ISO image doesn't result in an error message that it *looks* like it should be throwing errors about invalid ISO image. In fact, I've even tried passing ALL NULL/EMPTY VALUES and with the exception of the $conn connection variable, I only get this "Cannot get installation XML" error message: $result = libvirt_domain_new( $conn, null, null, null, null, null, null, [], [] ); Shouldn't I at least be seeing a message like "Name is 'myvm', memMB is 2048, maxmemMB is 8192" ? https://github.com/php/pecl-virtualization-libvirt/blob/master/src/libvirt-…

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How to make the libvirt VM installed under the regular user boot during the system bootup?
by Martin T 21 Mar '22

21 Mar '22

Hi. I installed a virtual machine under a regular user(in other words, not under root user) with virt-install and configured this VM to boot automatically: $ virsh dominfo vm Id: 1 Name: vm UUID: eef95dd6-5efe-4059-8dcc-3e35db12f55d OS Type: hvm State: running CPU(s): 4 CPU time: 253.7s Max memory: 4194304 KiB Used memory: 4194304 KiB Persistent: yes Autostart: enable Managed save: no Security model: none Security DOI: 0 $ ls -l /home/user/.config/libvirt/qemu/autostart/ total 0 lrwxrwxrwx 1 user user 47 Apr 30 16:59 vm.xml -> /home/user/.config/libvirt/qemu/vm.xml $ The vm indeed starts automatically, but only when the regular user has logged in. I would like libvirtd(started by the systemd) to execute this VM already during the system bootup when the regular user has not yet logged in. How to accomplish this? I also made a symlink under /etc/libvirt/qemu/autostart/, but this did not help. thanks, Martin

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how to reliably shutdown domains ?
by Lentes, Bernd 10 Mar '22

10 Mar '22

Hey guys, i have a two-node cluster with around 20 domains. Cluster-Software is pacemaker and corosync, OS is SLES 12 SP5. The scripts for starting/stopping the domains use virsh. Is there a way to reliably shutdown the domains via virsh ? I'm testing around, but sometimes the domains stop, sometimes they don't, sometimes it takes very long so that the cluster times out and fence the respective node. I'm using "virsh shutdown domain --mode acpi,agent" for the windows domains (not reliable) and for the linux domains "virsh shutdown domain", also not reliable. What can i do ? Bernd -- Bernd Lentes System Administrator Institute for Metabolism and Cell Death (MCD) Building 25 - office 122 HelmholtzZentrum München bernd.lentes(a)helmholtz-muenchen.de phone: +49 89 3187 1241 fax: +49 89 3187 2294 http://www.helmholtz-muenchen.de/mcd Public key: 30 82 01 0a 02 82 01 01 00 b3 72 3e ce 2c 0a 6f 58 49 2c 92 23 c7 b9 c1 ff 6c 3a 53 be f7 9e e9 24 b7 49 fa 3c e8 de 28 85 2c d3 ed f7 70 03 3f 4d 82 fc cc 96 4f 18 27 1f df 25 b3 13 00 db 4b 1d ec 7f 1b cf f9 cd e8 5b 1f 11 b3 a7 48 f8 c8 37 ed 41 ff 18 9f d7 83 51 a9 bd 86 c2 32 b3 d6 2d 77 ff 32 83 92 67 9e ae ae 9c 99 ce 42 27 6f bf d8 c2 a1 54 fd 2b 6b 12 65 0e 8a 79 56 be 53 89 70 51 02 6a eb 76 b8 92 25 2d 88 aa 57 08 42 ef 57 fb fe 00 71 8e 90 ef b2 e3 22 f3 34 4f 7b f1 c4 b1 7c 2f 1d 6f bd c8 a6 a1 1f 25 f3 e4 4b 6a 23 d3 d2 fa 27 ae 97 80 a3 f0 5a c4 50 4a 45 e3 45 4d 82 9f 8b 87 90 d0 f9 92 2d a7 d2 67 53 e6 ae 1e 72 3e e9 e0 c9 d3 1c 23 e0 75 78 4a 45 60 94 f8 e3 03 0b 09 85 08 d0 6c f3 ff ce fa 50 25 d9 da 81 7b 2a dc 9e 28 8b 83 04 b4 0a 9f 37 b8 ac 58 f1 38 43 0e 72 af 02 03 01 00 01

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Resize backing store
by Jeff Brown 08 Mar '22

08 Mar '22

Apologies in advance if this be a stupid question, as everything I've read seems to suggest it's impossible. Slowly running out of space on a 200GB root partition. Is it possible to create a snapshot - leaving the QCOW2 image 'quiescent' - resize it using 'qemu-img resize' - then pivot the snapshot back? (Then shutdown, attach the storage to another bootable OS, and run fdisk and resize2fs.) Everything I've read says to shutdown the VM; but besides the real possibility of the snapshot blockcommit being corrupted when pivoted into the newly resized backing store, I don't see why it shouldn't work. And save some significant downtime. Please can someone advise if this is actually possible, or if I'm wasting my time? Thanks! -- Jeff Brown Future Foundation Cell 074 101 5170 VoIP 087 550 1210 Fax: 086 532 3508

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About RO connection
by Xingbo Kan 08 Mar '22

08 Mar '22

Dear developers and users: Is there any standard or convention of which kind of APIs&flags could be invoked by RO connection? If there is any, please tell me in detail, thanks a lot! Kind regards, xkan

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