XFS – How to Remove a Project ID from XFS Project Quota

disk-space-utilizationquotaxfs

I successfully use xfs project (or directory) quota. However I just discovered that I am unable to remove quota information once I don't need it anymore.
For example, I had 3 projects with project id 1, 2, 3. I removed the directory of the project with id 2, and now xfs_quota continues to tell me that there is is a project with id 2, and it has quota. The reported used space is 0, which is correct since the directory was removed. This is not a real problem. Whenever I reuse project id 2 I will set new quota, but I'd still like to remove this useless information from the filesystem.

/etc/projects

1:/web/perso/usera
3:/web/perso/userc

/etc/projid

usera:1
userc:3

And here is what xfs_quota reports.

root@server # xfs_quota -xc "report -a -p -h" 
Project quota on /web (/dev/vdb1)
                        Blocks              
Project ID   Used   Soft   Hard Warn/Grace   
---------- --------------------------------- 
#0         588.3M      0      0  00 [------]
usera        5.5M    14G    14G  00 [------]
#2              0   980M     1G  00 [------]
userc      574.6M    14G    14G  00 [------]

How can I tell xfs that it does not need anymore to keep track of project id 2 ?

Best Answer

Setting limits to 0 while the project is still in /etc/{projid,projects}removes the project from metadata. After that it can be removed from /etc/{projid,projects}.

xfs_quota -x -c 'limit -p bsoft=0 bhard=0 foo' /path

I came across this by chance.

Related Solutions

Enabling quota and doing quotacheck on reboot

Ubuntu takes care of installing the startup script and periodic quota warnings. Look at the filelist of the quota package, /etc/init.d/quota turns quotas on:

on=/sbin/quotaon
# snip
ALLFLAGS=-aug
# snip
$on $ALLFLAGS

The cron file at /etc/cron.daily/quota runs /usr/sbin/warnquota. Note that quota's are working realtime, warnquota mails the user if they've exceeded their soft limit.

Linux – XFS Adding Quotas – Skip Quota check on first mount/boot

If you use xfs, you will always have that problem:

(quotaon manpage)

   "XFS filesystems are a special case - XFS considers quota information as
   filesystem  metadata  and  uses  journaling  to  provide a higher level
   guarantee of consistency.  There are two components  to  the  XFS  disk
   quota  system:  accounting  and  limit  enforcement.   XFS  filesystems
   require that quota accounting be  turned  on  at  mount  time.   It  is
   possible  to  enable and disable limit enforcement on an XFS filesystem
   after quota accounting is already turned on.  The default is to turn on
   both accounting and enforcement."

Also , from xfs_quota manpage:

   disable [ -gpu ] [ -v ]
          Disables  quota  enforcement,  while  leaving  quota  accounting
          active. The -v option (verbose) displays  the  state  after  the
          operation has completed.

   off [ -gpu ] [ -v ]
          Permanently  switches quota off for the filesystem identified by
          the current path.  **Quota can only be  switched  back  on  subse‐
          quently by unmounting and then mounting again.**

As it has to get quota accounting up to date it will be checking the whole volume, 14Tbytes will take a long time.

One option is to disable limit enforcement but it will still need to check quota accounting and it might still take much time, if you want to try, don't mount it at boot time by setting the 'noauto' flag and then disable it from a shell.

I suppose that you are not wondering to change the filesystem type, what would allow you to manage quotas 'online' , or even creating an image (with xfsdump or xfscopy) of that volume, applying quotas to it once mounted and then, via rsync, update its contents with the one online, that would also work as a backup, but that second option would also take much time.

Sorry for the bad news, I hope someone may give you a better solution.

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