User Management / Disk Space Quotas

Setting quotas

• Setting quotas for user and group (in your favorite editor $EDITOR)
  edquota -u USER_NAME
  edquota -g GROUP_NAME
• Changing grace period (default is 7 days, it is quite ok)
  edquota -t
• To rapidly set the same quotas for many users, you should first edit quotas for one user by hand, and the rest might use him as a template:
  edquota -p TEMPLATE_USER USER_NAME
  edquota -p TEMPLATE_USER ‘perl -F: -ane 'print "$F[0]\n" if ($F[2] > 499 && $F[2] < 10000)' /etc/passwd’

  later command will set the quotas as have TEMPLATE_USER for all the rest system users from /etc/passwd with UID more or equal to 500 and less than 10000. FIXME: users' UID range is still under consideration.

Note!  Right after system installation quotas should be switched on first, see below!

Monitoring quotas

• Watch quotas
  repquota -v /export
  repquota -v /export/grid

  You should see all your users, something like:

    [root@kvartsi etc]# repquota -v /export/
    *** Report for user quotas on device /dev/cciss/c1d0p2
    Block grace time: 7days; Inode grace time: 7days
                            Block limits                File limits
    User            used    soft    hard  grace    used  soft  hard  grace
    ----------------------------------------------------------------------
    root      -- 1310828       0       0          12559     0     0
    cscadmin  --    5032       0       0             55     0     0
  
    Statistics:
    Total blocks: 8
    Data blocks: 1
    Entries: 3
    Used average: 3.000000
  

  Right after installation quotas are on, but all zero.

• Watch quota for particular user
  quota -v -s USER_NAME

Enabling quotas at front-end

You need to perform this step only once, right after install. The kernel should have support for quotas (version 2), and rpc.rquotad server, to provide quotas over NFS, should be running.

Before making changes, make sure that nobody is using the filesystems (quotacheck will try to remount it read-only). Further are instructions for /export and /export/grid at front-end:

1. Add 'usrquota' and 'grpquota' options to /etc/fstab:

   LABEL=/export       /export       ext3   defaults,usrquota,grpquota  1 2
   LABEL=/export/grid  /export/grid  ext3   defaults,usrquota,grpquota  1 2

2. Remount filesystems
   mount -o remount /export
   mount -o remount /export/grid
3. Build a table of current disk usage (for current filesystem)
   quotacheck -vicug /export
   quotacheck -vicug /export/grid

   After this step files aquota.user and aquota.group should be located at filesystem root with quotas.

4. Switch the quotas on:
   quotaon -vug /export
   quotaon -vug /export/grid

The only possible way to check that quotas work, try to exceed them, set them for some user USER_NAME, let's say 200MB. Then try to fill it over.

You should get the error, about exceeding quotas. Try the same command on some of compute nodes, to get the same result over NFS. Don't forget to remove ~USER_NAME/output after you are done.