Diskpar on EVA4000/6000/8000 ?

[Thor-Ivar Lund_1]

Hi. Do we still have to use DiskPar to allign the disks on EVA 4/6/8k for W2k or W2k3?
I find differents answers to it here on the forum.
Anyone who about know this for sure?

[Steven Clementi]

I believe the issue is more OS related, rather than Storage related. I know several engineers that still use diskpar on the new eva's, aside from my self. The case is the same, the hiddensectors value is 63 when you look at the disk with diskpar.


Steven

[Mark Poeschl_2]

As far as I know setting the sector offset to 64 is still the recommended best practice for all Vdisks in use by any flavor of Windows.

[Thor-Ivar Lund_1]

Hi, thx for your replies.
I was digging around and
found a statement in a doc from HP that says that the EVA8000 doesnt need this anymore.

Page 7:
http://h71028.www7.hp.com/enterprise/downloads/PerformConfig_Exchange2003_EVA8000_1105.pdf

I expect this will be the same for EVA 4000 and 6000 then also?

[Nigel Poulton]

Hi,

I personally like to see statements like the one in the referenced document written down in several manuals and confirmed by the odd firmware engineer before I believe it. Ive known many times in the past where there have been typos and mistakes in manuals and PDF files.

OK Ive looked at the page in the PDF that you mention and thats certainly not your average typo ;-) However, I would personally still be a little skeptical without something more substantial to back it up.

For me, if I see a partition on a Windows box that is not track aligned on a 4K boundary then I will track align it (unless its already in production of course....). In the past I have always recommended this to server admins for new builds.

However, Im now wondering if this is bad advice. The document says that the "EVA 8K no longer requires alignment for increased performance..".

Does this mean that if tools such as diskpar or diskpart are used to force alignment they will actually adversely affect the performance of the filesystem because the EVA has already compensated for the size of the MBR??

-OR-

Does this mean that alignment is no longer relevant on the 8K. Id be surprised if this were the case. May be I "surprised" is not the right word, may be "impressed" would be better. Or even "skeptical" wihtout some documentation to back it up.

mackem

[Steven Clementi]

And why only on the 8000 and not the 4000/6000?

It would be nice to "know" why it is not needed anymore, on an 8000 anyway.

;o)

[Thor-Ivar Lund_1]

I agree.
I had the feeling that this was very unclear.
That's why I posted it. And I'm still confused.

Strange that HP can't give any clear answer on this if it really can do up to 20% performance gain! (I've even read from 2% to 95% also somewhere)

Or at least that it wont do any harm to align it. Then we could do it just to be on the safe side.

[Ian Vaughan · Accepted solution]

Howdy,
The problem was in the 3.x firmware and was resolved in the 5.x XCS for 4/6/8000's - it won't make a difference on those models if you use diskpar or not now. Haven't heard how the 4.x (new active-active ) VCS handles the offset.

I always use the best practices guide first & foremost but I've put in 8 or 9 4/6/8000's this year and not used diskpar on any of them

Hope this helps
Ian

http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual〈=en&cc=us&docIndexId=179111&taskId=101&prodTypeId=12169&prodSeriesId=321347

[Nigel Poulton]

OK Ive had a bit of a poke around and am starting to become more of a believer.

Page 27 of the document on the link at the bottom of this post agrees with the last posters comment relating to firmware versions in relation to XCS. However, still nothing on VCS formware versions...

This also says that the use of diskpar will not add to or detract from the performance of an EVA running XCS 5.xxx. Thats good to know as Ive recommended the use of diskpar and diskpart on some 4K/6K/8K installations.

I guess that unless we can russle something up for VCS firmware then it appears to be still best practice to manually sector align. It seems at least that even if its not longer required on VCS that doing it wont be doing any harm.

mackem

http://h71028.www7.hp.com/ERC/downloads/4AA0-2787ENW.pdf

[Thor-Ivar Lund_1]

Excellent.
Thx a lot Ian and Mackem.

Why did'nt I see that myself... ?
:-|