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 currently located on the machine home.fi.muni.cz and is exported using NFS and SMB protocols
• on the bundle /data/ login with user data, which is currently located on the machine home.fi.muni.cz and is exported using NFS and SMB protocols; the quota 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/mail with mail (does not apply to employee mailboxes on anxur machine)
• on the machines aisa.fi.muni.cz and anxur.fi.muni.cz on the volumes /tmp and /var/tmp for temporary files

Quota limits disk space as well as 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). After the timeout, 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 you to exceed the hard limit. If an operation causes the hard limit to be exceeded, it will not complete and will end with an error.

Checking the status of quotas

All set limits on volumes can be found 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 -v . Example:

aisa$ quota -v
Disk quotas for user login (uid 5555):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
/dev/mapper/vg0-tmp
                    820  2000000 4000000             194   50000   80000
/dev/mapper/vg0-mail
                      4  150000  180000               1      50     100
/dev/mapper/vg0-vartmp
                     72  2000000 4000000               9   50000   80000
home.fi.muni.cz:/export/usrdata/xnahoda
                   1024  100000000 150000000               5  600000  700000
home.fi.muni.cz:/export/home/xnahoda
                1912792  2000000  3000000            8717   80000  100000

nymfeXY$ quota -v
Disk quotas for user login (uid 5555):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
home.fi.muni.cz:/export/home/xnahoda
                2100500* 2000000 3000000   6days     8718   80000  100000
home.fi.muni.cz:/export/usrdata/xnahoda
                   1024  100000000 150000000               5  600000  700000

The examples show quota detection on the aisa and nymph machines. The first three columns are in kilobytes, and the last three specify the number of files. Quotas for volumes can be seen at aisy /tmp (/dev/mapper/vg0-tmp) , /var/mail (/dev/mapper/vg0-mail) , /var/tmp (/dev/mapper/vg0-vartmp) and then for home.fi.muni.cz:/export/usrdata/xnahoda and home.fi.muni.cz:/export/home/xnahoda .

The last line is usually the most important, as it displays quota information in the home directory, even if another person's login is displayed xnahoda. This is because from one physical home machine they are using the program automounter the home directories of other logged-in users and the command are also mounted as separate volumes quota by default, it prints a quota only for the first mount point found on one physical device. Thus, despite the slightly misleading description, the information displayed in this way is relevant and actually indicates the quota for the current user's home directory.

In the second example, we similarly see first the quota on the home directory (with a different login for the same reasons as described above) and the quota on the directory /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 timeout 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/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.

How do I know 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, arranges them by size, and lists the 10 largest. 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 .