>
> filemon.pl ? That tool was available also for the Solaris {SPARC,x86}
> too, wasn't it? I think I remember using that 11 years ago :)The filemon.pl I was describing I got it from here: Determining If There is an I/O Bottleneck in LVM http://www-128.ibm.com/developerworks/blogs/page/aixpert?entry=determining_if_there_is_an [OT] Not so sure Solaris has this also but its a very neat tool in doing perf tuning at least for AIX system. > > Anyway, iostat(1) on RHEL 5.1 (fresh install, unpatched) would tell me > that my /dev/hda2 (i.e. /dev/dm-0) and /dev/hdb1 (ie. /dev/dm-1) were > at 100% utilization. Top(1) would show that all my CPUs were pegged > with 100% wait states. It was pretty insane. > > Then I saw that multiple processes of kryptd were hogging the CPUs. In > the background, I was mkfs'ing a 500GB SATA2 HDD with XFS, while the > 1TB SATA2 HDD (both set at 3Gb i/o speeds) were mkfs'ed with EXT3. And > oh yeah, I was also burning to DVD a copy of the Solaris 10 x86 > installer (yeah, I got a license for that too ;) with a SATA2 DVD > writer too (all three SATA2 channels on the motherboard are taxed). > > Using taskset(1), I checked each of the kcryptd's CPU affinity, and > found out that they would each bind themselves automagically to one > selected CPU. That wasn't funny. I did remember then that in Fedora 8, > the kryptd's CPU affinity mask was set to F, or bound to all CPU's. So > I manually taskset'ed each kcryptd to only three CPUs, and reserved > one CPU for me, then lo and behold! My system became more stable. > > I tried to live with RHEL 5.1 for most of the night, hacking up a > script to manually bind any krcyptd that I find to three CPU's, but > that was annoying. So I could just get on with my life, I went with > Fedora 9, installed VMware on it and everything else I wanted, patched > it all up, and never looked back. Using my Fedora 9 right now, there's > no performance hit at all that can be felt --unless I do my strings(1) > then grep(1) on 100+GB files again, but that's another story. > > And of course I checked kcryptd behavior on my current Fedora 9. > They're all set with CPU affinity mask of F. Then Red Hat may have a fixed for that issue already.... my speculation up2date have the automagic fix available. but according to your next thread you are using an eval copy.......plus xfs which is outside the scope of supported ext3 I have been bitten by a lot of bugs RHEL 4 64 bit install using the installer CDs...called support and re-configured up2date it automagically fixed all the bugs I encountered.....TCO+SLA met the clients expectations.... -- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ sometimes truth is stranger than fiction -bad religion- http://www.bloglines.com/blog/mailist ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ I don't think the computers will take over the world. I have a bucket of water. _________________________________________________ Philippine Linux Users' Group (PLUG) Mailing List http://lists.linux.org.ph/mailman/listinfo/plug Searchable Archives: http://archives.free.net.ph
