[lustre-discuss] "Not on preferred path" error
Joe Landman
landman at scalableinformatics.com
Tue Sep 20 09:29:33 PDT 2016
On 09/20/2016 12:21 PM, Lewis Hyatt wrote:
> We do not know if it's related, but this same OSS is in a very bad
> state, with very high load average (200), very high I/O wait time, and
> taking many seconds to respond to each read request, making the array
> more or less unusable. That's the problem we are trying to fix.
This sounds like a storage system failure. Queuing up of IOs to drive
the load to 200 usually means something is broken elsewhere in the stack
at a lower level. Not always ... sometimes you have users who like to
write several million/billion small ( < 100 byte ) files.
What does dmesg report? Try to do a pastebin/gist of it, and point it
to the list.
Things that come to mind are
a) offlined RAID (most likely): This would explain the user load, and
all sorts of strange messages about block devices and file systems in
the logs
b) A user DoS against the storage: usually someone writing many tiny files.
There are other possibilities, but these seem more likely.
--
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics, Inc.
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