HAST + ZFS + NFS + CARP

[Miroslav Lachman]

Ben RUBSON wrote on 07/01/2016 13:58:

>> With ZFS send & receive you will lose some writes but the chance you will corrupt both pools are much lower than in the first case and the setup is much simpler and runtime error proof.
>
> Only some ?
> Depending on the write throughput, won't you loose a lot of data on the target/slave ?
> How do you make ZFS send/receive quite realtime ?
> while [ 1 ] do ; snapshot ; send/receive ; delete old snapshots ; done ?

It depends on throughput and how often do you send. But you need to 
compare it to the HAST / iSCSI scenario. Even with this setup ZFS don't 
write to disk immediately but in batch delayed according to some sysctl 
settings and you will lose this amount of data in all cases + data on 
clients which cannot write and must restart their NFS sessions (again 
this apply to HAST / iSCSI scenario)

If you will ZFS send often, you can lose about 2 or 4 times more. It 
depends on you if it is too much or not.

Miroslav Lachman