On Thu, 1 Jan 2009, Kostas Georgiou wrote: > On Thu, Jan 01, 2009 at 01:17:38AM -0600, Mike McGrath wrote: > > > On Thu, 1 Jan 2009, James Antill wrote: > > > > > On Wed, 2008-12-31 at 14:42 -0600, Mike McGrath wrote: > > > > Lets pool some knowledge together because at this point, I'm missing > > > > something. > > > > > > > > I've been doing all measurements with sar as bonnie, etc, causes builds to > > > > timeout. > > > > > > > > Problem: We're seeing slower then normal disk IO. At least I think we > > > > are. This is a PERC5/E and MD1000 array. > > > > > > > > When I try to do a normal copy "cp -adv /mnt/koji/packages /tmp/" I get > > > > around 4-6MBytes/s > > > > > > This _might_ not be "IO" in a normal sense, -a to cp means: > > > > > > file data + file inode + ACLs + selinux + xattrs [+ file capabilities] > > > > > > ...esp. given that you aren't getting large IOWait times, you might want > > > to strace -T the cp and do some perl/whatever on the result to see what > > > is eating up the time. > > > > Even with non cp type things (like a bacula backup) it just doesn't seem > > as fast as I would expect it to be. I've never actually done trending at > > this level / scale on a filesystem / drive before. So I really don't have > > a good baseline except that it just seems slow to me. > > > > Other then the much faster direct block access and the large file reads, I > > don't have much else to go on that makes me think its slow. > > Do writes show the same pattern? If you use selinux/ACLs/xattrs the default > inode size of 128 can cause slowdowns (#205161 for example). > > Can you run blktrace+seekwatcher (both in EPEL) to get an idea on > what is going on? An iostat -x -k /dev/sde 1 output will also be > helpfull. > Here's a seekwatcher of a find I ran: http://mmcgrath.fedorapeople.org/find2.png I had to kill it, I'll have a more full run soon. Doing some other tests now. -Mike _______________________________________________ Fedora-infrastructure-list mailing list Fedora-infrastructure-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-infrastructure-list
