First Proxmox replication mode

[wolfgang]

Failed !

It tells me there is not VM 100 to replicate.

This is odd but I would need the concert output to make a statement.

result show pve-zsync only from host where i launch the command to replicate is it normal ?

Yes this tool is a standalone tool so it has no communication between more instances.

 

[Benoit]

ok you give me the answer ...

i'm a little disturbed by memory usage on my host ... i just start to create my VM on them and memory increase not normally

host : 64Gb of RAM

two Windows VM with 4Gb RAM each

RAM usage on host : 34Gb


Why ?

I do not have that on my others Proxmox hosts, where i don't use zfs ... is it zfs that use this amount of RAM ?

I found that i can modify /etc/sysctl.conf to modify swappiness and /sys/module/zfs/parameters/zfs_arc_max to modify amount of RAM used by ZFS

what do you think about it ?

 

[wolfgang]

ZFS loves memory and take as much as can default about 50% of system memory only for ZFS.

With the zfs_arc_max you can set it to a lower value.

 

[Benoit]

ok thanks for the reply

So i have to put on value zfs_arc_max the total amount of memory RAM minus the total amount of RAM used by my VM ?

 

[wolfgang]

Yes plus 1G Host and 1G reserve.

 

[Benoit]

ok done !

For my usage the initial goal of using pve-zsync is to be able to recover a VM on other host if host is down

i found that on the web :

Recovering an VM

You must recover the VM or dataset manually. (In one of the upcoming releases, the restore for Proxmox VE VM will be integrated).

Fist, stop the sync job for the VM or dataset in question.

NOTE: if not you can be interfere the sync job or your snapshot will removed before you are able to send it.


root@zfs2:~# pve-zsync disable --source 192.168.15.1:100 --name test
root@zfs2:~# pve-zsync list
SOURCE NAME STATE LAST SYNC TYPE
192.168.15.1:100 test stopped2015-06-12_11:03:01 ssh


Then you can send the VM or Dataset to the selected target. SSH is only needed if you send to a remote sever.


zfs send <pool>/[<path>/]vm-<VMID>-disk-<number>@<last_snapshot> | [ssh root@<destination>] zfs receive <pool>/<path>/vm-<VMID>-disk-<number>


If you have a VM you must also copy the config and you need to correct the virtual disk storage configuration accordingly.


cp /var/lib/pve-zsync/<VMID>.conf.rep_<JOB_NAME><VMID>_<TIMESTAMP> /etc/pve/qemu-server/<VMID>.conf


Thoses commands are ok when host is alive if i understand, because we use command

zfs send <pool>/[<path>/]vm-<VMID>-disk-<number>@<last_snapshot> | [ssh root@<destination>] zfs receive <pool>/<path>/vm-<VMID>-disk-<number>


how can i do if host is down ??

 

[wolfgang]

You can also receive with local host.
The idea is a generic way to restore.

 

[Benoit]

to make a test recovering VM on second host with first host down, can you drive me with the commands i have to use ?