Hi all,
I am sorry if this is not strictly in the correct place.
Performance issues led me in the direction of the reallocation command, and I am struggling to understand when and if I should be using it (previous thread regarding Exchange defrags & reallocation: http://communities.netapp.com/message/54944#54944). So I have some questions:
I am seeing performance issues on my largest volumes - namely our 800Gb NFS volume used as VM datastore, and our 350Gb Exchange 2003 volume:-
1) Should I be scheduling reallocate tasks on these vols, or even on the aggregate? Do they offer any real performance benefit? (seeing as all vols are deduped anyway?).
2) I see performance problems when Exchange is running an "online defrag" of it databases, and especially when performing a backup "verify". I read somewhere that someone experienced a 40% improvement in read times after performing a weekly reallocation on their Notes database vol. As an SMSQL/Exchange verify is mostly reads I guess, should I also be using it?
3) What about my VMware datastore and SQL volumes? Should I also schedule reallocation on these volumes?
I hope someone has prior experience of using reallocation in Exchange, SQL and VMware environments and can give me some pointers. I can't seem to find any conclusive advice - I even read that I shouldnt run reallocation unless instructred to do so by our NetApp support vendor!
What is clear to me is that any large database verifications, or defrags cause a significant performance hit on my filer.
Help as always appreciated.
M.
[udpate: I ran a "reallocation measure -o" on my Exchange vol, and it says "reallocation check is 9, threshold is 4. Consider running reallocate". I guess this is answering my question for me?]