On Sat, Sep 27, 2008 at 01:46:39PM +1000, Rob Mueller wrote: > > > > >Where's the first place to look for this problem? I/O statistics > >show a higher read bandwidth while the backup is running, but writes > >still dominate. The backup would typically read all of the files in > >a single Cyrus partition. > > Some more information about your setup would be helpful. I deliberately omitted that information, hoping that somebody would know what happens on the server side when mutt says `selecting INBOX'. I don't want to redesign the server at this stage, at least not until I've isolated the problem. > 1. Make sure you have noatime (and nodiratime if applicable) set on your FS > 2. If on linux, use the deadline IO scheduler > 3. If you can, split your data and meta data onto separate volumes > (probably a lot of work) > 4. Install more RAM and use a 64-bit OS. x64_64 linux can cache many, many > more inodes and dentries in memory than x86 linux. > 5. Upgrade to the latest cyrus and enable the status cache Those are all good suggestions. I'll investigate some of them. -- -Gary Mills- -Unix Support- -U of M Academic Computing and Networking- ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
