[Dovecot] Significant performance problems

[Chris Hobbs]

  On 10/6/10 6:28 PM, Rick Romero wrote:
> Is your disk a virtual disk as well?  Have you checked performance?  
> Something like:
> | hdparm -tT /dev/sda|
>
> On a ZFS RAID 10 of 10 7200RPM SATA drives, I get about 100MB/s
>
> At work we have an EMC SAN, and I get like 350MB/s on that beast - but 
> if this is just a vhd on a Windows box, that could be an issue..
>
The disks are virtual on an EMC iSCSI san. I know you're supposed to run 
hdparm when things are quiet, but trying it now (somewhat quiet) I get:

on the NFS server:
  Timing cached reads:   11844 MB in  2.00 seconds = 5928.81 MB/sec
  Timing buffered disk reads:  176 MB in  3.00 seconds =  58.62 MB/sec

on the dovecot server (where indexes are stored):
  Timing cached reads:   12310 MB in  2.00 seconds = 6162.13 MB/sec
  Timing buffered disk reads:  230 MB in  3.02 seconds =  76.22 MB/sec

-- 
Chris Hobbs
Director, Technology
New Haven Unified School District

--
This message was scanned by ESVA and is believed to be clean.