Slurm accounts, QOS and limits¶

The state of the Phoebe accounting database in September 2026. Check the current values with sacctmgr show qos and sacctmgr show assoc.

Accounts¶

All accounts hang directly under root with a fair-share weight of 1, and default to the normal QOS.

Account	Who	Users
`fzu_a_16`	FZU division 16	8
`fzu_a_29`	FZU division 29	13
`fzu_a_39`	FZU division 39	32
`ext_ceico`	external collaborators of CEICO	8
`ext_fzu`	external collaborators of FZU	3
`fzu_project001`	one special project	1

The accounts are only for internal accounting. The admin picks the account when adding a new user: the user's FZU division, or ext_ceico / ext_fzu for people from outside FZU. Users don't need to know their account or pass --account to their jobs.

Two associations in fzu_a_29 have their own group GPU limits: GrpTRES=gres/gpu=8 and GrpTRES=gres/gpu=4.

QOS¶

QOS	Priority	Per-user limit	Per-job limit	Associations with it as default
`normal`	256	16 A100 GPUs (`gres/gpu:a100=16`), 3000 running jobs	-	60
`manyjobs`	100	128 CPUs, 3000 running jobs; flag `OverPartQOS`	-	1
`newbie`	500	5 running jobs	-	0
`max400cpu`	0	3000 CPUs	-	2
`max500cpu`	0	1 CPU	-	1
`max64cpu`	0	64 CPUs	-	0
one per-user QOS (named after its user)	0	128 CPUs	-	0
`gpu_max2`	0	3 GPUs	16 CPUs, 3 GPUs, 504 GB	2

In the last 90 days, 20 042 jobs ran with normal, 64 with max400cpu and 10 with gpu_max2.

Add a user¶

Create the user in the accounting database and add them to an account:

sacctmgr create user name=UserName account=AccountName

The user gets the account's default QOS, normal.

Give a user another QOS¶

Allow the QOS and make it the user's default:

sacctmgr modify user name=UserName set qos=max64cpu defaultqos=max64cpu

Use qos+= instead of qos= to add a QOS without removing the others. Jobs already in the queue keep their old QOS; change them one by one:

scontrol update job=123456 qos=max64cpu

Create a QOS with a per-user limit¶

For example, at most 400 CPUs per user:

sacctmgr create qos cpu400
sacctmgr modify qos cpu400 set maxtresperuser=cpu=400

Change the per-user GPU limit¶

The GPU limit for everyone lives in the normal QOS:

sacctmgr modify qos normal set maxtresperuser=gres/gpu:a100=16