I am very new for Linux Mail Server administration.
The mail server limits each client storage maximum size by Quota.

I have now two questions regarding to Quota management.
As first, I feel that when sometime and some client may reach to the limit, the server may fall into hung-up like status. Each occasion I need to reboot the server to let server wack up. When such an occasion occur I check every clients disk consuming size by using "repquota -a" command, then usually I can find some users.

Then now, as second question, even though "repquota" shows client's information being over given Quota blocks as like;

[root@kin ccc]# repquota -v /dev/sda9
(username) -- 1962916 1800000 2000000 66 0 0

Now, on the other hand, because this /dev/sda9 is the storage give to client to keep Dovecot IMAP protocol messages on the server, thus I check the client's folder by using "du -a" as shown as;

[root@kin ccc]# du -a (username)
.....
(IMAP Folder and files listed with consumed size)
.....
631684 (username)

Above is just one of example where I have experienced.

Here, I would like to summary my questions as follows.
(1) May excess over Quota Limit cause for Server un-stable running?
The Server runs Red Hut Linux Enterprise V5 and Dovecot IMAP.
(2) Is it normal that both of repquota and du command are different size shown?

Because of these questions, I am wondering what and how I should do to solve my server's unstable running status. Kindly please provide me any direction where I should go to.

Thanks and regards.
Y.Nakano

Hello Nakano

I don't have Red Hut Linux Enterprise V5 and Dovecot IMA but nobody else has replied yet ...

Surely hitting a user's quota limit affects a service that is creating files for users! A well-programmed service would detect file creation error (for any reason, including quota limit) and take graceful action rather than hang or become unstable.

Regards the du/repquota discrepancy ...

Check the man page for your specific repquota. Most man pages say it reports in kilobytes, others do not specify the unit. The quota suite works in "blocks". Each file system is formatted with a particular blocksize, usually 1 kB. I don't know if the quota system works in fixed-size (1 kB) blocks or in the block size of each file system. What is the block size on the /dec/sda9 file system?

Please confirm that you running [root@kin ccc]# du -a <username> in a directory on /dev/sda9 that contains a directory called <username> which contains only files belonging to <username>, including any hidden (.*) files?

Are you absolutely sure that <username> has no other files on the /dev/sda9 file system?

What does du report with the --apparent-size option?

Does Dovecot IMA create sparse files?

Best

Charles