[Snic-users] Triolith and Gamma unavailable October 19th/20th

[Mats Kronberg]

Dear NSC users,

On October 19th and 20th, both Triolith and Gamma will be unavailable.

Start of downtime: 2016-10-19 08:00 CEST
Estimated duration of downtime: 24-48h

During this stop NSC will perform maintenance and testing, e.g

- A major software upgrade of the Centre Storage (/home, /proj)
  system, including tuning and benchmarking after the upgrade.
- Hardware maintenance of Centre Storage (a tricky problem best
  repaired while the system is shut down)
- Infiniband subnet manager testing

If you have any questions regarding this, please contact support at nsc.liu.se.


Details
-------

All login nodes (including ThinLinc) and compute nodes will be
unavailable during this time, and will be restarted during the stop.

Queued jobs will only start if the timelimit requested (i.e "sbatch -t
DD-HH:MM:SS") is less than the time remaining before the start of the
downtime.

If you need to run jobs in the week before the downtime, you might
need to shorten your jobs.

Jobs that are in the queue before the downtime will remain in the
queue, and will be started normally after the downtime.


Opportunities
-------------

If your project has a low priority due to having run a lot recently,
you might find it much easier than usual to get short jobs started in
the days immediately before downtime as they don't have to compete
with longer jobs. However, please note that core hours used for such
jobs will still be counted, so your priority will be even less after
the downtime if you take advantage of this.

If your project has a need to run wide and short jobs (i.e jobs using
many nodes for a short period of time) for e.g scaling tests, this is
a very good opportunity to do that. Please contact support at nsc.liu.se
and describe your needs (e.g number of jobs and their sizes) and we'll
get back to you with more information. Please note that such jobs are
not "free", the core hour cost to your project is the same as always,
but this is a possibility to run such jobs without inconveniencing
other users (see
https://www.nsc.liu.se/support/batch-jobs/triolith/#flatjobs)


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