The EOS quota system provides user, group and project quota similiar to filesystems like EXT4, XFS ... e.g. quota is expressed as max. number of inodes(=files) and maximum volume. The implementation of EOS quota uses the given inode limit as hard quota, while volume is applied as soft quota e.g. it can be slightly exceeded.
Quota is attached to a so called ‘quota node’. A quota node defines the quota rules and counting for a subtree of the namespace. If the subtree contains another quota node in a deeper directory level quota is rooted on the deeper node.
As an example we can define two quota nodes:
Node Path Quota Node 1 /eos/lhc/raw/ Quota Node 2 /eos/lhc/raw/analysis/
A file like /eos/lhc/raw/2013/raw-higgs.root is accounted for in the first quota node, while a file /eos/lhc/raw/analysis/histo-higgs.root is accounted for in the second quota node.
The quota system is easiest explained lookint at the output of a quota command in the EOS shell:
eosdevsrv1:# eos quota
# _______________________________________________________________________________________________
# ==> Quota Node: /eos/dev/2rep/
# _______________________________________________________________________________________________
user used bytes logi bytes used files aval bytes aval logib aval files filled[%] vol-status ino-status
adm 2.00 GB 1.00 GB 8.00 - 1.00 TB 0.5 TB 1.00 M- 0.00 ok ok
The above configuration defines user quota for user adm with 1 TB of volume quota and 1 Mio inodes under the directory subtree /eos/dev/plain. As you may notice EOS distinguishes between logical bytes and (physical) bytes. Imagine a quota node subtree is configured to store 2 replica for each file, then a 1 TB quota allows you effectivly to store 0.5 TB (aval logib = 0.5 TB!).
Warning
All quota set via the ‘quota set’ command is defining the (physical) bytes and EOS displays the logical bytes value based on the layout definition on the quota node.
The volume and inode status is displayed as ‘ok’ if there is quota left for volume/inodes. If there is less than 5% left, ‘warning’ is displayed, if there is none left ‘exceeded’. If volume and/or inode quota is set to 0 ‘ignored’ is displayed. In this case a quota setting of 0 signals not to apply the quota however if both are ‘0’ the referenced UID/GID has no quota.
There are three types of quota defined in EOS: user, group & project quota!
User quota defines volume/inode quota based on user id UID. It is possible to combine user and group quota on a quota node. In this case both have to ‘ok’ e.g. provide enough space for a file placmment.
Group quota defines volume/inode quota based on group id GID. As described before it is possible to combine group and user quota. In this case both have to allow file placement.
Project quota books all volume/inode usage under the project subtree to a single project account. E.g. the recycle bin uses this quota type to measure a subtree size. In the EOS shell interface project quota is currently defined setting quota for group 99:
eosdevsrv1:# eos set -g 99 -p /eos/lhc/higgs-project/ -v 1P -i 100M
It is possible to set a physical space restriction using the space parameter nominalsize
# restrict the physical space usage to 1P
eosdevsrv1:# eos space config default space.nominalsize=1P
The restriction is only used, if the connected user is not in the sudoer list. The current usage and space setting is cached for 30s e.g. it might take up to 30s until any change may take effect.
Quota enforcement is applied when new files are placed and when files in RW mode are closed e.g. EOS can reject to store a file if the quota exceeds during an upload. If user and group quota is defined, both are applied.
To see your quota as a user use:
eosdevsrv1:# eos quota
To see quota of all users (if you are an admin):
eosdevsrv1:# eos quota ls
To see the quota node for a particular directory/subtree:
eosdevsrv1:# eos quota ls /eos/lhc/higgs-project/
The syntax to set quota is:
eos quota set -u <uid>|-g <gid> [-v <bytes>] [-i <inodes>] -p <path>
The <uid>, <gid> parameter can be numerica or the real name. Volume and Inodes can be specified as 1M, 1P etc. or a plain number.
A quota setting can be removed using:
eos quota rm -u <uid> |-g <gid> -p <path>
One has to specify to remove the user or the group quota, it is not possible to remove both with a single command.
Sometimes it is necessary to remove completely a quota node. This can be done via:
eos quota rmnode -p <path>
The command will ask for a security code. Be aware the quota is not recalculated from scratch if the deletion of a node would now leave the accounting to an upstream node.