Dell Perc pveperf values

[gbr]

Hi,

I've inherited a Dell Perc controller that identifies as an LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 08)
My pveperf numbers are not very good on it. Any ideas?

root@proxmox-3:~# pveperf /local
CPU BOGOMIPS: 19999.36
REGEX/SECOND: 968742
HD SIZE: 687.17 GB (/dev/sdc1)
BUFFERED READS: 74.98 MB/sec
AVERAGE SEEK TIME: 11.85 ms
FSYNCS/SECOND: 48.64
DNS EXT: 27.80 ms
DNS INT: 0.65 ms

Gerald

 

[mmenaz]

Yes, you need to activate the "write back" cache, not write trough. But you need to protect that cache with a BBU, or have the perc controller that has the non-volatile version of the cache (or something like that).
The raid controller disables the hard disk "on board cache" since they can loose data in case of powerloss, and does not enable the write back for the same reason. If you have BBU then you can safely enable and your values will jump > 2500 FSYNC/sec

 

[gbr]

That's a good question actually. I don't have the original paperwork for these machines, so I don't know if BBU is on them or not. Time to do more research.

Gerald