Are you seeing high IO wait CPU use, or high IO wait times on IO? Adrian 2009/8/2 smaugadi <adi@xxxxxxxxxxxx>: > > Dear Adrian, > Well my conclusion that this is an IO problem came from the fact that I see > huge IO waits as the volume of traffic increase (with tools such as mpstat), > when using ramdisk there is no such issue. > I have configured the SSD drive with ext2, no journal, noatime. Used the > “noop” I/O scheduler. > In /etc/fstab > /dev/sdb1 /cache ext2 defaults,noatime 1 2 > > hdparm results: > hdparm -t /dev/sdb1 > > /dev/sdb1: > Timing buffered disk reads: 304 MB in 3.01 seconds = 100.93 MB/sec > ---- > hdparm -T /dev/sdb1 > > /dev/sdb1: > Timing cached reads: 4192 MB in 2.00 seconds = 2096.58 MB/sec > > Any ideas? > > Regards. > > > > Adrian Chadd-3 wrote: >> >> 2009/8/2 smaugadi <adi@xxxxxxxxxxxx>: >>> >>> Dear Adrian, >>> During the implementation we encountered issues with all kind of >>> variables >>> such as: >>> Limit of file descriptors (now the squid is using 204800). >>> TCP port range was low (increased to 1024 65535) TCP timers (changed >>> them) >>> The ip_conntrack and hash size were low (now 524288 262144 respectively) >>> >>> Now we are at a point that IO is the only issue. >> >> What profiling have you done to support that? For example, one of the >> issues I had which looked like IO performance was actually because the >> controller was completely unhappy. Upgrading the firmware on the >> controller card signficantly increased performance. >> >> But I think you need to post some further information about the >> problem. "IO" can be rooted in a lot of issues. :) >> >> >> Adrian >> >> > > -- > View this message in context: http://www.nabble.com/Squid-high-bandwidth-IO-issue-%28ramdisk-SSD%29-tp24775448p24776193.html > Sent from the Squid - Users mailing list archive at Nabble.com. > >
