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Storage and quotas

In our network you will find disk quotas for machines with Unix OS and Windows OS .

Unix

On Unix machines, each user has the following storage available, limited by a disk quota:

  • on the bundle /home/ login with the home directory, which is located on the machine home.fi.muni.cz and is exported using NFS and SMB protocols; storage is backed up
  • on the bundle /data/ login with user data, which is located on the machine home.fi.muni.cz and is exported using NFS and SMB protocols; the quota here is an order of magnitude higher than in the home directory, but the volume is not backed up and access to it may be slower
  • on the machine aisa.fi.muni.cz on the volume /var/spool/mail with mail (does not apply to employee mailboxes on the Anxur machine)
  • on the machines aisa.fi.muni.cz and anxur.fi.muni.cz on the volumes /tmp and /var/tmp for temporary files

See also the possibility of remote connection of these storages .

If you are interested, you can read more about our disk storage solution in our blog post .

The quota limits the disk space and the number of files stored. The limitation of each of these resources is given by the soft quota, the hard quota and the time limit, the meaning of which is as follows. After exceeding the soft quota, the user is set a time limit until which he can work normally. However, the system notifies him of the exceeded quota - a notification e-mail is sent and the notification is also displayed in the order statement quota (see below). When the timeout expires, the user is restricted from accessing the quota-exceeded volume (it is not possible to create new files and increase the size of existing files), and the user must delete sufficient data and / or files to restore access. The system will not allow the hard limit to be exceeded. If an operation causes the hard limit to be exceeded, it will not complete and will result in an error.

Checking quota status

You can find all the set limits on the volumes in Faculty administration in the My Account - Overview section. To find out the current occupancy values and space limits and number of files on a specific machine, enter the command quota . Example:

aisa$ quota
Disk quotas for user login (uid 55555):
Filesystem       space   quota   limit  grace  files  quota  limit  grace
/var/spool/mail  12K     147M    176M   0      2      50     100    0
/var/tmp         0K      1954M   3907M  0      0      50000  80000  0
/tmp             4K      1954M   3907M  0      2      50000  80000  0
/home/login      47408K  3907M   4883M  0      5841   160k   200k   0
/data/login      4K      97657M  144G   0      2      600k   700k   0

nymfeXY$ quota
Disk quotas for user login (uid 55555):
Filesystem       space   quota   limit  grace  files  quota  limit  grace
/home/login      4882M*  3907M   4883M  6d     5841   160k   200k   0
/data/login      4K      97657M  144G   0      2      600k   700k   0

The examples show quota detection on the Aisa and Nymph machines. The first three columns indicate the size, followed by a delay, and then the same for the number of files. Aisy quotas can be seen at Aisa /var/spool/mail , /var/tmp , /tmp and then /home/login and /data/login .

The penultimate line is usually the most important because it displays quota information in the home directory.

In the second example, we similarly see the quota on the home directory and the quota on the directory first /data/login with user data. This example also shows how to command quota informs about quota overrun. The number exceeded is followed by an asterisk and the running time limit is displayed in the grace column.

When the quota is exceeded

When the quota is threatened to be exceeded, we automatically send a message to the faculty address. After exceeding the quota on the volume aisa:/var/spool/mail the mailbox is moved to the home directory and the user is also informed by a message.

If the home directory quota is exceeded, then graphical login to the system may mysteriously fail. However, if you do not encounter a hard quota on your home directory and you do not have an expiration date after exceeding the soft quota, you will be notified of a quota problem and will be notified by email. Login via text interface ( Ctrl-Alt-Fn ) or SSH should always work for you.

How do I find out which files take up the most space

Log in to your account (eg using ssh) and run the following from the command line:

$ du -kax | sort -n | tail -n 10
323316  ./.cpanm/work/1329993381.18167
340828  ./mail/misclass
350480  ./.Spotlight-V100/Store-V1
350488  ./.Spotlight-V100
367740  ./.cpanm/work
367820  ./.cpanm
414276  ./prog
627336  ./.ccache
2420912 ./mail
7762344 .

This command lists the space used in kB in all directories and files (even hidden ones) in the home directory, sorts them by size, and lists the 10 largest. Or you can also use the interactive tool ncdu :

$ ncdu

In this case, we could delete some unnecessary files:

$ rm -rf .ccache .cpanm/work

You can do the same for a volume /data/ login You just need to get into it before executing the command du switch:

$ cd /data/
login
$ du -kax | sort -n | tail -n 10
...

The above command du however, it may not always reveal the cause of the quota being filled. The listing shows only the space used by the files in the given directory, but the quota is calculated over the entire volume ( /home resp. /data ) and the owner of the file is decisive. If the data from the statement of orders quota and du significantly different, this may mean that some files owned by the current user are located in another user's directory (or vice versa). In this case, it is necessary to remember where they can be located and, if necessary, ask the user to access / delete the files. If you've tried the options here and are still unsure, contact the administrator at unix@fi.muni.cz .