EVA4400 - 1TB Drives lead to instability?

[IvanForceville]

Had a little chat with HP Support... and they mentioned they had seen numerous issues with the 1TB drives in the EVA4400.

Anyone experiencing this issue? We have a couple of them but since they are in a diskgroup we hardly use, so difficult to tell.

[Uwe Zessin]

I have not seen problems myself or at my customers because I do disrecommend FATAl disk drives or at least try to make crystal clear what they are intended for.

One big problem was that the quality was obviously missing something. Another one is that customers seem to misunderstand their purpose as I often hear arguments like: those servers don't do 'much IO' or their applications 'do not need fast disks'.

The very first firmware revision(s) of the EVA-4400 did not support the 1TB disks and this information was/is apparently missed by some people which is one cause of troubles.

In the early days FATAl disk drives were highly recommended and even positioned for the use of the CA write-history-log (WHL). Some time ago this has changed and the controller firmware now selects an FC disk group for the WHL
:-O

Another problem that is sometimes seen on larger configurations is that an overloaded FATAl disk group can drag down the performance of a whole EVA - the reason is an unfortunate design how I/Os to the disk drives are scheduled.

If you don't put to much and/or continuous load on them, make sure they are on the current firmware revision (or don't let them get too cold - not a joke !), or keep them outside of your EVA (ha! that was the joke) - you should be fine.

[Víctor Cespón · Accepted solution]

1 TB FATA drives need firmware HP06. Currently there no big known issues with them. As Uwe says, FATA disks are intended for only 30% duty cycle and sequential access.

That means no databases, no VmWare VM stored on them. If the FATA disk group becomes saturated, it will take all the RAM available for cache and slow down the access to other disk groups. If this happens you can disable write cache on the vdisks on the FATA disk group, this will leave more free RAM for the vdisks needing more speed.

[IvanForceville]

Thx for the information.

We recently upgraded to HP06.
Glad to hear that purpose of the FATA drives need to be chosen well... so misuse can lead to "problems" with the EVA :)

We had an 8 disk FATA Diskgroup... I know... I know... but it was just for test purposes.
We will be extending the group with another 8 drives.

[IvanForceville]

Case Closed.