OSCER users,


OSCER scheduled maintenance outage Wed Feb 28 8am-midnight.

Systems affected: supercomputer, OURdisk, OURcloud, 
OURRstore tape archive.

Details are earlier in this e-mail thread.



Before the scheduled maintenance outage starts on 
Wed Feb 28 8:00am:

Jobs that wouldn't finish before the scheduled maintenance 
outage starts won't be able to start at all, until after the 
scheduled maintenance outage has ended (planned for 
Wed night at midnight).

Because, by this approach, such jobs can run for 
the full wall clock time limit that they've requested.

So, if you want a job to run before the scheduled 
maintenance outage begins, then in your batch scripts, 
you might need to reduce the amount of wall clock 
time limit you request.

(Once the maintenance period ends, this won't apply 
any more.)

If you have jobs that you've already submitted that are 
pending in the queue, then you might want to reduce 
their requested wall clock time limit, to give them 
a chance to start before the scheduled maintenance 
outage begins.

The command is:

scontrol update JobId=######## TimeLimit=DD-HH:MM:SS

except REPLACE ######## with the job ID number, and 
REPLACE DD-HH:MM:SS with 2-digit number of days, 
2-digit number of hours (beyond the number of days), 
2-digit number of minutes (beyond the days and hours) 
and 2-digit number of seconds (beyond the days, hours 
and minutes).

You have to pick a wall clock time limit short enough that 
the job can run to its time limit before the start of the 
scheduled maintenance outage.

For example, suppose job 123456 had requested 48 hours of 
wall clock time limit, but now there are less than 48 hours 
before the start of the scheduled maintenance outage.

So job 123456 won't be able to run until after the 
scheduled maintenance outage ends.

But, we could change the requested wall clock time limit 
for job 123456 to, for example, 30 hours, like this:

scontrol update JobId=123456 TimeLimit=01-06:00:00

In that case, job 123456 would have a *CHANCE
(but *NOT A GUARANTEE*) to run before the outage starts.


From: OSCER users <[log in to unmask]> on behalf of Neeman, Henry J. <[log in to unmask]>
Sent: Thursday, February 22, 2024 10:57 AM
To: [log in to unmask] <[log in to unmask]>
Subject: OSCER scheduled maintenance outage Wed Feb 28 8am-midnight

OSCER users,

OSCER will hold a scheduled maintenance outage Wed Feb 28 8am-midnight.

Systems affected: supercomputer, OURdisk, OURcloud, OURRstore tape archive.

The OSCER team will perform the following maintenance items (time permitting), 
in the following priority order:

(1) Shift to a new user database instance.

(2) Update Linux on OURdisk.

(3) Decommission our one older OURdisk monitor node (we have 
5 newer monitor nodes, which are already in production alongside 
the one older one, and the recommendation is to have either 3 or 5).

(4) Time permitting, upgrade one of the condominium compute nodes to 
25GE (from its current 10GE).

(5) Time permitting, reconfigure the routing of the supercomputer's 
Infiniband-to-Ethernet gateway appliances, and shift onto these 
IB-to-Ethernet gateway appliances the network traffic of 
(i) one compute node (for testing) and (ii) one of our scratch subsystems.

(6) Time permitting, shift all nodes to the IB-to-Eth gateway appliances.

We apologize for the inconvenience -- as always, our goal is to make 
OSCER resources even better!


Henry Neeman ([log in to unmask])
Director, OU Supercomputing Center for Education & Research (OSCER)
Associate Professor, Gallogly College of Engineering
Adjunct Associate Professor, School of Computer Science
OU Information Technology
The University of Oklahoma

Engineering Lab 212, 200 Felgar St, Norman OK 73019
405-325-5386 (office), 405-325-5486 (fax), 405-245-3823 (cell),
[log in to unmask] (to email me a text message)