[PVE-User] Shared storage on NAS speed - LVM(over iSCSI) vs NFS

[Eneko Lacunza]

El 19/07/17 a las 08:41, Dietmar Maurer escribió:
>> So I cannot figure out why LVM-over-iSCSI is so slow.
> I guess your benchmark is simply wrong. You are testing the
> local cache, because you do not sync the data back to the storage.
Really, 2.7GB/s for 4x4TB disks in RAID10 seems totally unreasonable (I 
guess they're not SSD drives...)

I think that in the best conditions that could give about 200-250MB/s 
max, totally sequential writes, etc.

Don't know why iSCSI is so slow, have you checked CPU usage on both sides?

Anyhow your test copy is too small, use a file that at least is double 
the available RAM on storage server, or otherwise force sync.

Cheers
Eneko

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