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? You have four 7.2K SATA stripe spindles. Do you mind posting the RAID10 strip/chunk size? The RAID geometry can be critical, not just for mail, but your entire VM setup. Also, what's your mdbox max file size? >> 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. 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. > Thanks again Stan... You bet. -- Stan