On 2013-05-03 11:10 PM, Stan Hoeppner <s...@hardwarefreak.com> wrote:
On 5/3/2013 9:21 AM, Charles Marcus wrote:
On 2013-05-03 8:34 AM, Stan Hoeppner <s...@hardwarefreak.com> wrote:
I assume /var will hold user mail dirs.
Yes, in /var/vmail
Do /var/ and /snaps reside on the same RAID array, physical disks?
Yes - vmware host is a Dell R515, with ESXi installed to mirrored
internal SATA drives, with 8 drives in RAID 10 for all of the VMs. All
storage is this local storage (no SAN/NAS).
Your RAID10 is on a PERC correct?
Correct... it is a PERC H700 (integrated)
You have four 7.2K SATA stripe spindles.
Actually, no, I have 6 15k 450G SAS6G hard drives (Seagate Cheetah
ST3450857SS) in this RAID10 array...
:)
Do you mind posting the RAID10 strip/chunk size? The RAID geometry can be
critical, not just for mail, but your entire VM setup.
I just used the defaults when I created it (crossing fingers hoping that
wasn't a huge mistake). But - I'm not sure how to provide the answer to
the question (is my ignorance showing yet?)...
Also, what's your mdbox max file size?
Haven't settled on that yet. I was thinking of using the defaults there
too. I try to stay with defaults whenever possible, especially if I
don't know enough to know why I would want to change something.
How about the other filesystems I snipped? If you have a large number
of filesystems atop the same RAID, some of them being XFS, this could
create a head thrashing problem under high load increasing latency and
thus response times.
Ouch...
Don't fret yet.
This ESXi host also hosts 2 server 2008R2 vms...
So, what, 3 production VMs total? That shouldn't be a problem,
unless... (read below)
Would you mind posting: ~$ xfs_info /dev/vg/var
meta-data=/dev/mapper/vg-var isize=256 agcount=4, agsize=45875200
...
meta-data=/dev/mapper/vg-snaps isize=256 agcount=4, agsize=262144 blks
Ok, good, mkfs gave you 4 AGs per filesystem, 8 between the two. This
shouldn't be a problem.
Cool...
However, ISTR you mentioning that your users transfer multi-GB files, up
to 50GB, on a somewhat regular basis, to/from the file server over GbE
at ~80-100MB/s. If these big copies hit the same 4 RAID10 spindles it
may tend to decrease IMAP response times due to seek contention. This
has nothing to do with XFS. It's the nature of shared storage.
I think you're confusing me/us with someone else. This is definitely not
something our users do, not even close. We do deal with a lot of large
email attachments though. I used to have a max size of 50MB, but reduced
it to 25MB about 8 months ago (equivalent of google's max size)...
So, looks like I'm fine with what I have now...
Thanks again,
--
Best regards,
Charles
