[Snic-users] Slow file system access on NSC Centre Storage (/home, /proj)

[Mats Kronberg]

Performance should now be back to normal. If you see any remaining
problems, please email support at nsc.liu.se.

We have identified the likely source of the problem, and will in the
coming days/weeks make changes and work with the storage vendor to try
to prevent the same thing happening again.


Technical details:

One user created over 3.2 million files during a short period today.
Each file consumes one "inode", and the number of inodes is limited.
The system will automatically create new inodes on demand when too few
are available, but apparently it created them slower than they were
used up, and this resulted in slow performance or "hangs", especially
when creating new files or directories.

Short-term, we will manually create more inodes to get a larger margin
for "bursts" of this kind. Long-term, we'll work with the storage
vendor to find out why the system did not perform as expected.

-- 
Mats Kronberg, NSC Support <support at nsc.liu.se>