On backup run a command before and after snapshot to lock mysql db inside VM
- Thread starter alexc
- Start date
Unlucky me, I can't see qma working while standard PVE backup.
I have "agent: 1" line in VM's .conf file, and I see VM started with qga support (note the bold chars):
/usr/bin/kvm -id 403 -chardev socket,id=qmp,path=/var/run/qemu-server/403.qmp,server,nowait -mon chardev=qmp,mode=control -vnc unix:/var/run/qemu-server/403.vnc,x509,password -pidfile /var/run/qemu-server/403.pid -daemonize -smbios type=1,uuid=358cbdd4-9579-4b82-9439-fc178ed03950 -name mysql-proxy -smp sockets=1,cores=1 -nodefaults -boot menu=on -vga cirrus -cpu kvm64,+lahf_lm,+x2apic,+sep -k en-us -m 512 -device piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2 -chardev socket,path=/var/run/qemu-server/403.qga,server,nowait,id=qga0 -device virtio-serial,id=qga0,bus=pci.0,addr=0x8 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -iscsi initiator-name=iqn.1993-08.org.debian:01:5f58918b684f -drive if=none,id=drive-ide2,media=cdrom,aio=native -device ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=200 -drive file=/var/lib/vz/images/403/vm-403-disk-1.qcow2,if=none,id=drive-virtio0,format=qcow2,aio=native,cache=none -device virtio-blk-pci,drive=drive-virtio0,id=virtio0,bus=pci.0,addr=0xa,bootindex=100 -netdev type=tap,id=net0,ifname=tap403i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown -device e1000,mac=56
F:995:7C:A5,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300
and I also can do something like:
root@proxmox:~# socat unix-connect:/var/run/qemu-server/403.qga stdin
{"execute": "guest-info"}
{"return": {"version": "2.1.0", "supported_commands": [{"enabled": true, "name": "guest-set-vcpus", "success-response": true}, {"enabled": true, "name": "guest-get-vcpus", "success-response": true}, {"enabled": true, "name": "guest-network-get-interfaces", "success-response": true}, {"enabled": true, "name": "guest-suspend-hybrid", "success-response": false}, {"enabled": true, "name": "guest-suspend-ram", "success-response": false}, {"enabled": true, "name": "guest-suspend-disk", "success-response": false}, {"enabled": true, "name": "guest-fstrim", "success-response": true}, {"enabled": true, "name": "guest-fsfreeze-thaw", "success-response": true}, {"enabled": true, "name": "guest-fsfreeze-freeze", "success-response": true}, {"enabled": true, "name": "guest-fsfreeze-status", "success-response": true}, {"enabled": true, "name": "guest-file-flush", "success-response": true}, {"enabled": true, "name": "guest-file-seek", "success-response": true}, {"enabled": true, "name": "guest-file-write", "success-response": true}, {"enabled": true, "name": "guest-file-read", "success-response": true}, {"enabled": true, "name": "guest-file-close", "success-response": true}, {"enabled": true, "name": "guest-file-open", "success-response": true}, {"enabled": true, "name": "guest-shutdown", "success-response": false}, {"enabled": true, "name": "guest-info", "success-response": true}, {"enabled": true, "name": "guest-set-time", "success-response": true}, {"enabled": true, "name": "guest-get-time", "success-response": true}, {"enabled": true, "name": "guest-ping", "success-response": true}, {"enabled": true, "name": "guest-sync", "success-response": true}, {"enabled": true, "name": "guest-sync-delimited", "success-response": true}]}}
...etc...
so it appears everything is ok. And I also see in the VM logs:
Jul 9 15:36:49 virt1 qemu-ga: info: guest-fsfreeze called
Jul 9 15:36:49 virt1 qemu-ga: info: executing fsfreeze hook with arg 'freeze'
Jul 9 15:37:00 virt1 qemu-ga: info: executing fsfreeze hook with arg 'thaw'
so the communication is fine.
But as PVE start its backup process no qga invocation is seen: neither in PVE vzdump logs, nor in VM logs.
What should I do now? We use PVE 3.3-1, but I don't think upgrading to 3.4 will solve this thing.
I have "agent: 1" line in VM's .conf file, and I see VM started with qga support (note the bold chars):
/usr/bin/kvm -id 403 -chardev socket,id=qmp,path=/var/run/qemu-server/403.qmp,server,nowait -mon chardev=qmp,mode=control -vnc unix:/var/run/qemu-server/403.vnc,x509,password -pidfile /var/run/qemu-server/403.pid -daemonize -smbios type=1,uuid=358cbdd4-9579-4b82-9439-fc178ed03950 -name mysql-proxy -smp sockets=1,cores=1 -nodefaults -boot menu=on -vga cirrus -cpu kvm64,+lahf_lm,+x2apic,+sep -k en-us -m 512 -device piix3-usb-uhci,id=uhci,bus=pci.0,addr=0x1.0x2 -chardev socket,path=/var/run/qemu-server/403.qga,server,nowait,id=qga0 -device virtio-serial,id=qga0,bus=pci.0,addr=0x8 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -iscsi initiator-name=iqn.1993-08.org.debian:01:5f58918b684f -drive if=none,id=drive-ide2,media=cdrom,aio=native -device ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=200 -drive file=/var/lib/vz/images/403/vm-403-disk-1.qcow2,if=none,id=drive-virtio0,format=qcow2,aio=native,cache=none -device virtio-blk-pci,drive=drive-virtio0,id=virtio0,bus=pci.0,addr=0xa,bootindex=100 -netdev type=tap,id=net0,ifname=tap403i0,script=/var/lib/qemu-server/pve-bridge,downscript=/var/lib/qemu-server/pve-bridgedown -device e1000,mac=56
F:995:7C:A5,netdev=net0,bus=pci.0,addr=0x12,id=net0,bootindex=300and I also can do something like:
root@proxmox:~# socat unix-connect:/var/run/qemu-server/403.qga stdin
{"execute": "guest-info"}
{"return": {"version": "2.1.0", "supported_commands": [{"enabled": true, "name": "guest-set-vcpus", "success-response": true}, {"enabled": true, "name": "guest-get-vcpus", "success-response": true}, {"enabled": true, "name": "guest-network-get-interfaces", "success-response": true}, {"enabled": true, "name": "guest-suspend-hybrid", "success-response": false}, {"enabled": true, "name": "guest-suspend-ram", "success-response": false}, {"enabled": true, "name": "guest-suspend-disk", "success-response": false}, {"enabled": true, "name": "guest-fstrim", "success-response": true}, {"enabled": true, "name": "guest-fsfreeze-thaw", "success-response": true}, {"enabled": true, "name": "guest-fsfreeze-freeze", "success-response": true}, {"enabled": true, "name": "guest-fsfreeze-status", "success-response": true}, {"enabled": true, "name": "guest-file-flush", "success-response": true}, {"enabled": true, "name": "guest-file-seek", "success-response": true}, {"enabled": true, "name": "guest-file-write", "success-response": true}, {"enabled": true, "name": "guest-file-read", "success-response": true}, {"enabled": true, "name": "guest-file-close", "success-response": true}, {"enabled": true, "name": "guest-file-open", "success-response": true}, {"enabled": true, "name": "guest-shutdown", "success-response": false}, {"enabled": true, "name": "guest-info", "success-response": true}, {"enabled": true, "name": "guest-set-time", "success-response": true}, {"enabled": true, "name": "guest-get-time", "success-response": true}, {"enabled": true, "name": "guest-ping", "success-response": true}, {"enabled": true, "name": "guest-sync", "success-response": true}, {"enabled": true, "name": "guest-sync-delimited", "success-response": true}]}}
...etc...
so it appears everything is ok. And I also see in the VM logs:
Jul 9 15:36:49 virt1 qemu-ga: info: guest-fsfreeze called
Jul 9 15:36:49 virt1 qemu-ga: info: executing fsfreeze hook with arg 'freeze'
Jul 9 15:37:00 virt1 qemu-ga: info: executing fsfreeze hook with arg 'thaw'
so the communication is fine.
But as PVE start its backup process no qga invocation is seen: neither in PVE vzdump logs, nor in VM logs.
What should I do now? We use PVE 3.3-1, but I don't think upgrading to 3.4 will solve this thing.
Upgrade, functionality you desire was added in 3.4 according to the roadmap:
http://pve.proxmox.com/wiki/Roadmap#Proxmox_VE_3.4
Unlucky me again, we stuck with 3.3 due to kind of instability we faced in 3.4. Once we already upgraded a test server from 3.3 to 3.4 but we were unsatisfied with the result. We decided to wait for 3.5 and test again.
But I suspect this is due to kernel and binary PVE utils (zfs support etc.) - I really wonder if it is possible to update only scripts? What package may this be to upgrade, by any chance?
May be I was not clear enough!
qga will only freeze the fs when you make a snapshot not a backup and also not if you make a backup in snapshot-mode.
This is not implemented.
Oh, sad to know that. So,
I can use qga (say, for flush mysql as per link I was given above) but it 1) will work since 3.4 and 2) will work only on qm snapshot, not on backup.
That is, all I can do is quietly ignore nice featurs of qga and try to create such a shell script:
ssh user@mysqlserver freeze_mysql
vzdump .... --script 'remote_unfreeze_mysql.pl'
where remote_unfreeze_mysql.pl will execure ssh user@mysqlserver unfreeze_mysql on event name 'pre-restart'. In this example freeze_mysql and unfreeze_mysql are some scripts that can stabilize mysql (as a quick example, simple stop it in freeze... and start it in unfreeze...), these scripts are on mysql server VM. remote_unfreeze_mysql.pl is local (on PVE) script that issue 'unfreeze...' over ssh.
A bit messy to explain, sorry, but what would you tell, it this will work?
That's strange. I'm using proxmox 3.4 and tested qga with an ubuntu 14.04 vm. When starting a backup in snapshot-mode, guest-fsfreeze is invoked according to syslog of guest vm:
Wolfgang, doesn't this contradict your statement?
The roadmap contradicts Wolfgang's statement:
http://pve.proxmox.com/wiki/Roadmap#Proxmox_VE_3.4
I think most important thing to point out to future readers of this thread is that this ability was only added in 3.4.
If you don't have >= 3.4, its not going to work.
http://pve.proxmox.com/wiki/Roadmap#Proxmox_VE_3.4
I think most important thing to point out to future readers of this thread is that this ability was only added in 3.4.
If you don't have >= 3.4, its not going to work.
Oh, thanks! ))
My problem is, we stuck with 3.3 (test for 3.4 given some unstable results so we decided to wait for 3.4+). I can't "just upgrade" server so I have to play with 3.3. So, may I somehow upgrade scripts (not the kernel) of PVE so this functions will be available to my scripts?
The topic of fs and software freezing/flushing is land unknown for many users while it is pretty convenient way to do really amazing thing. Hope I'll be able to create such a miracle now (of course with your help)!
My problem is, we stuck with 3.3 (test for 3.4 given some unstable results so we decided to wait for 3.4+). I can't "just upgrade" server so I have to play with 3.3. So, may I somehow upgrade scripts (not the kernel) of PVE so this functions will be available to my scripts?
The topic of fs and software freezing/flushing is land unknown for many users while it is pretty convenient way to do really amazing thing. Hope I'll be able to create such a miracle now (of course with your help)!