[Bug 1057054] Re: poor performance after upgrade to Precise
peter.petrakis at canonical.com
Thu Sep 27 17:49:04 UTC 2012
Then the only possible actors left are the actual initramdisk contents e.g.
zcat <initrd> | cpio -id and examine all the scripts (init, conf/modules) to determine
how it could be loaded. The absence of the module reference in all of /etc and
/usr/share/initramfs-tools/ tell me that whatever is loading that module is doing
so as a side effect or an administration artifact e.g. someone wrote a udev rule and forgot.
Another possible source and this is also way out in left field is if modules.dep
was compromised and scsi_sh_rdac was added as dependency of another module
and thus loaded indirectly.
root at nashira:/lib/modules/2.6.32-41-generic# grep scsi_dh modules*
Binary file modules.dep.bin matches
root at nashira:/lib/modules/2.6.32-41-generic# vim modules.dep
root at nashira:/lib/modules/2.6.32-41-generic# vim modules.builtin
concerning boot probe, scsi discovery is asymmetric, there's no expectation
of order. Performance tuning is where I get off, I also don't know much about
iSCSI transport, though yeah, jumbo frames it probably wise.
If you're seeing those messages before the file system is mounted then
the actors are definitely *in the ramdisk*, you just need to find them.
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to multipath-tools in Ubuntu.
poor performance after upgrade to Precise
Status in “multipath-tools” package in Ubuntu:
I had a Lucid x64 server working with a Dell MD3000i with 4 paths and
worked as expected. I added the "prio rdac" line to the conf file,
then upgraded to Precise, and removed the old mpath_rdac line and
reboot one more time, just to be sure. I did this based on a section
as a "sanity check" test, I'm doing 'pv < /dev/mapper/dellsas1 >
/dev/null' (friendly names enabled). On Lucid i'd get about 100MB/s
After upgrading to Precise I get an almost solid 768kB/s. If I
instead use the 4 underlying /dev/sd* devices, 2 give errors as
expected, and 2 run at about 100MB/s as expected so iscsi seems to be
working correctly and multipath not.
To manage notifications about this bug go to:
More information about the foundations-bugs