|
In order to keep filesystems from filling up and disrupting work, we use filesystem quotas to limit usage in certain areas by user or group. This also helps us observe growth in disk usage over time so we can plan future expansion.
By default, the filesystem quotas are as follows:
filesystem | quota (maximum total data size allowed) | file limit (maximum number of files allowed) |
---|---|---|
| 100 GiB per user | none |
| varies by lab/group | none |
| varies by lab/group | none |
|
|
25 TiB per user |
2, |
500,000 files or directories |
/n/scratch_gpu
15 TiB per user*
none
* scratch_gpu
is only available for labs whose PI has a primary or secondary appointment in a pre-clinical HMS department.
Checking UsageChecking Usage
HMS Research Computing has retired the older tool for checking personal and group storage utilization and limits called quota
on August 8, 2023. The replacement tool called quota-v2
retrieves more comprehensive information than the previous quota
tool, executes faster, and runs on all O2 nodes (login, compute, and transfer cluster).
More information can be found in the extended quota-v2 documentation, which details the meaning of column and table in the quota-v2
output.
You can use the quota-v2
and du
commands to check filesystem usage.
Usage by User and Group
The quota-v2
command on O2 will show your usage and usage by groups of which you are a member for directories (accessible on O2) that have quotas imposed.
Type quota-v2
at the command prompt on any O2 system. The output will look something like:
Code Block |
---|
/home [i] Usage for mfk8 (As usageof 2022-10-04 16:28:47 EDT-0400) warning┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ┃ path limit ===== ┃ type ┃ username ----- ┃ usage ------- -----┃ storage limit ┃ userlast mfk8update ┃ (uid 5005) 75GiB 95GiB 100GiB * /n/groups [f]┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩ │ /home │ usageuser │ mfk8 warning limit ========= │ 44.76 GiB │ 100 GiB ----- ------- ----- group smith│ 2022-10-04 16:28:59 EDT-0400 │ ├────────────────────────────────────────────┼───────┼─────────────────────┼─────────────┼───────────────┼──────────────────────────────┤ │ /n/groups/smith │ user (gid 3204)│ mfk8 142GiB user mfk8 │ 18.67 GiB │ (uid 5005) │ 2022-10-04 16:28:47 EDT-0400 │ 17GiB├────────────────────────────────────────────┼───────┼─────────────────────┼─────────────┼───────────────┼──────────────────────────────┤ │ /n/groups/smith [f] │ group │ usage warning limit =================== │ 13.02 TiB │ 50 TiB ----- ------- -----│ 2022-10-04 16:28:47 EDT-0400 │ ├────────────────────────────────────────────┼───────┼─────────────────────┼─────────────┼───────────────┼──────────────────────────────┤ │ /n/scratch/users directory │ user │ mfk8 142GiB │ 56.43 GiB │ 25 TiB 200GiB clusters ======== [ f - itisimdcp05 as of 2021-05-10 13:00:01 ] based on default quota -- * [ i - itisimdcp10 as of 2021-05-10 13:00:00 ] usage exceeds limit --- !│ 2022-10-04 16:28:59 EDT-0400 │ └────────────────────────────────────────────┴───────┴─────────────────────┴─────────────┴───────────────┴──────────────────────────────┘ |
You will see a number representing your individual storage usage in your /home
directory on the "user" line above with the 100GiB quota. If you’re using /n/scratch
, you’ll see a line for your personal usage in your sub-directory within /n/scratch/users
.
Note: It is against RC policy to artificially refresh last access time of any file located under /n/scratch.
For more information on the "directory" line. Also, if scratch, please refer to the dedicated scratch wiki page.
If you are a member of a group directory, you'll have a line for your “user” usage above the "directorygroup" line showing all group members' usage.
If you have reached a quota limit, you will see an exclamation mark or !
at the end of the line for the directory that has exceeded the quotaextra “exceeded” table which denotes which paths have exceeded their quotas.
The quota data is updated on an hourly basis. You can tell how recent the data you're viewing is from the timestamp at in the bottom last column of the quota-v2
output. It is possible to hit a quota limit (e.g. in your home directory or your group directory) but not have the output from the quota-v2
command reflect this problem for about an hour due to the information being periodically updated.
scratch3 quotas
For data on /n/scratch3
, you need to use the scratch3_quota.sh command:
...
Note that "limit" is the total amount of space you are allowed to use. ("quota" is actually describing a "soft quota" where you get a warning but can still write. The /n/scratch3
filesystem doesn't use these.)
Note: It is against RC policy to artificially refresh last access time of any file located under /n/scratch3.
For more information on scratch3, please refer to the dedicated scratch3 wiki page.
scratch_gpu quotas
Research Computing is no longer providing the /n/scratch_gpu
filesystem. Please use /n/scratch3
instead.
Usage by Directory
Another way to check usage is to total the size of files in a directory using the du
command. For example, you might want to see how much space your sub-directory in your group's shared directory is consuming:
...
Note that
du
can take quite some time for directories containing large numbers (tens of thousands or more) of files, because it must check the size of every file to compute the total. In general, it is better to usequota
-v2 to find usage information, when possible, or at least to rundu
on sub-directories instead of top-level directories.
...
You can verify that you are over quota by running the quota-v2
command. If you see an !
a red exceeded
table at the end of a line of the output, then it means you have hit or exceeded a limit.
...
Use the commands above to confirm that you are above your quota, and delete data as needed to let you write new files again.
Note that the quota-v2
command results are only updated hourly. If you were writing files very rapidly, the quota-v2
command might not show a completely full quota. Also, deleting files won't immediately change the results from that command. If you delete 5 GiB of files, you should be able to write 5 GiB of new files in that location immediately, even if quota-v2
hasn't caught up yet.
You can delete a whole directory with a command like rm -rf dir
. Please be careful when using a command like this: you could delete all of your files!
...