Replication timers with ZFS in regards to reading data from ARC

[mailinglists]

Hi guys,

I have a few VMs on PM 5 with set replication using ZFS.
I used to set */30 or more for replication schedule.
Just now I set it to */1 for every VM because counter intuitively, it might put less work for the source disks.
The reasoning is that, if we sync often, then the data to be synced, can be still in RAM (ARC) and it has not have to be read from disks.
If we wait more, then data might have already left ARC and it has to be read from disks for the sync.

Is this idea correct? What do you guys think?

 

[guletz]

HI,

I think it depens by so many factors. The best is to test various sync time interval, for each VM/groups of VM, and then see what is the best in your case.