On Wed, Oct 27, 2010 at 01:06:18PM +0200, Ivan Voras wrote: > On 10/27/10 12:55, David Wolfskill wrote: > > > That *is* a problem, as I cannot justify a migration to a branch > > of FreeBSD that imposes about a 23% penalty in elapsed time on this > > workload. I want folks at work to have more reason to want to use > > (newer branches of) FreeBSD, not less. > > That is understandable,
:-} > I'm only saying that given the symptoms - some > "waiting" that is not accounted in system or user time and with NFS > mostly ruled out (maybe a better test would be to extract a local > tarball *to* the NFS server), I could run that test, sure.... > the next suspect is the disk system. In > case you never tried "diskinfo -vt", its results look like this: > > outside: 102400 kbytes in 1.222998 sec = 83729 kbytes/sec > middle: 102400 kbytes in 1.448580 sec = 70690 kbytes/sec > inside: 102400 kbytes in 2.531694 sec = 40447 kbytes/sec > > note 2x drop in performance between outer and inner tracks. OK, but I'm not sure how that's likely to work for a multi-spindle RAID 0 group.... > It's not > certain, especially since your results are repeatable and you always use > exactly the same file system, For the NFS tests just done. For the "real" tests, the same file system was used when I ran the tests on the same machine; (obviously) different machines have different (local) file systems. (Still, similarly- configured 4-spindle RAID 0 groups were used for the target file systems on each machine.) > but it's possible. Have you tried the sysctls I've posted? Err... Not yet, no. I just got up & read your message. I leave for work in just over 3 hours. :-} [While it is possible to login from home, it's a liitle more awkward than (say) logging in to the FreeBSD cluster, and this is the time of day when I reboot my laptop a few times -- it's presently running 9.0-CURRENT #23 r214372 & building 9.0-CURRENT #23 r214413; it just finished building & smoke-testing FreeBSD 8.1-STABLE #14 r214413.] Peace, david -- David H. Wolfskill da...@catwhisker.org Depriving a girl or boy of an opportunity for education is evil. See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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