On Tue, Apr 28, 2009 at 6:20 AM, Fajar A. Nugraha <fajar@xxxxxxxxx
> On Tue, Apr 28, 2009 at 7:59 PM, Antoine Benkemoun
>> Thank you for your answer. Sorry for the headers !
>> 4MB/s read speed is just plain ridiculous for a hard drive or is it just me
> I don't think its the transfer rate. Its the IOPS thats causing your problems.
> This link (from Googling "one disk iops")
> indicates max IOPS for one disk is lower then your current numbers
> (180). So I guess you're IOPS bound. Adding more disk with the right
> setup would increase the number of IOPS you can handle.
> Since the IOPS are mostly read, you MIGHT be able to reduce it by
> giving domU more RAM, enough to hold the torrent it's running. So
> instead of having 8 domUs with 256 MB each, try using only 1 or 2
> domUs with 1 GB memory.
>> These domains are actually stored on LVM so that's already in place but
>> iostat doesn't seem to differenciate...
> Weird. I swear in shows up on RHEL. Could be they have vendor-specific
> patch. What does /proc/partitions and /proc/diskstats show, does it
> have "dm" entries?
> Anyway, from the output of "xm top" you should also be able to
> determine which domU uses most I/O (look in VBD_RD column). In general
> bittorrent IS very I/O intensive. If you want to limit the amount of
> I/O a domU can use (so that whatever they do they never made the
> entire system crawl down), you might be interested in dm-ioband.
> Haven't used it myself, but it looks good.