HPE EVA Storage

Expected FATA performance

 
Drenalen
Occasional Contributor

Expected FATA performance

We have a FATA disk group in an EVA8400 with 35 7200 1TB FATA disks. Im aware that performance on these things is not comparable to FC however the disk group is slower than expected.

 

Transfering data from a FC lun to a FATA lun (via a SLES 10 box using native mpio and round robin) will bring the EVA to a grinding halt. The avg mb's is 10-15. The controller cache fills up and latency picks up across all luns on the EVA.

 

To combat this i have changed the cache policy on the lun to write though, so it does not impact the whole EVA just the one FC port on the owning controller. This controller then sits at max qdepth trying to process the i/o's at a slow and steady 10mb/s. Am i expecting too much from FATA or does this sound about right?

 

Cheers.

1 REPLY 1
Uwe Zessin
Honored Contributor

Re: Expected FATA performance

Yes, I am afraid you are expecting too much from them :-(

It won't help you, but you're not the first one who as fallen into the FATAl trap.

 

Whatever any shining sales sheet says - in my opinion (and experience) they're barely useful for anything except writing or reading a file now and then.

 

Do NOT use them for "servers that don't /NEED/ fast disks" !!

Do NOT use them for backup or even multi-stream backup to disk !!

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