How to safely free up disk space

This article provides information on how to safely free up disk space on the MX80 platform.

During a Junos upgrade on the MX80 platform, the following warning message may be generated:

WARNING: The /var filesystem is low on free disk space.
WARNING: This package requires 557888k free, but there
WARNING: is only 158640k available.

WARNING: The /var filesystem is low on free disk space.

WARNING: This package requires 557888k free, but there

WARNING: is only 158640k available.

By checking the file system, you might notice that the /var file system lacks free space:

lab@MX80-a> show system storage 
Filesystem       Size       Used       Avail        Capacity      Mounted on
/dev/da0s1a      885M       122M       692M         15%           /
devfs            1.0K       1.0K       0B           100%          /dev
/dev/md0         41M        41M        0B           100%          /packages/mnt/jbase
/dev/md1         178M       178M       0B           100%          /packages/mnt/jkernel-ppc-12.2R1.8
/dev/md2         34M        34M        0B           100%          /packages/mnt/jpfe-MX80-12.2R1.8
/dev/md3         6.5M       6.5M       0B           100%          /packages/mnt/jdocs-12.2R1.8
/dev/md4         54M        54M        0B           100%          /packages/mnt/jroute-ppc-12.2R1.8
/dev/md5         12M        12M        0B           100%          /packages/mnt/jcrypto-ppc-12.2R1.8
/dev/md6         2.8G       10.0K      2.6G         0%            /tmp
/dev/md7         2.8G       11M        2.6G         0%            /mfs
/dev/da0s1e      98M        272K       90M          0%            /config
procfs           4.0K       4.0K       0B           100%          /proc
/dev/da1s1f      2.8G       2.1G       445M         83%           /var

lab@MX80-a> show system storage

Filesystem Size Used Avail Capacity Mounted on

/dev/da0s1a 885M 122M 692M 15% /

devfs 1.0K 1.0K 0B 100% /dev

/dev/md0 41M 41M 0B 100% /packages/mnt/jbase

/dev/md1 178M 178M 0B 100% /packages/mnt/jkernel-ppc-12.2R1.8

/dev/md2 34M 34M 0B 100% /packages/mnt/jpfe-MX80-12.2R1.8

/dev/md3 6.5M 6.5M 0B 100% /packages/mnt/jdocs-12.2R1.8

/dev/md4 54M 54M 0B 100% /packages/mnt/jroute-ppc-12.2R1.8

/dev/md5 12M 12M 0B 100% /packages/mnt/jcrypto-ppc-12.2R1.8

/dev/md6 2.8G 10.0K 2.6G 0% /tmp

/dev/md7 2.8G 11M 2.6G 0% /mfs

/dev/da0s1e 98M 272K 90M 0% /config

procfs 4.0K 4.0K 0B 100% /proc

/dev/da1s1f 2.8G 2.1G 445M 83% /var

There is only 445M free space on the /var file system.

You can use the following CLI command to clean up the hard disk:

request system storage cleanup dry-run

1	request system storage cleanup dry-run

By using the dry-run statement, Junos will list (but not delete) all the large files on the hard disk:

lab@MX80-a> request system storage cleanup dry-run 

List of files to delete:

Size        Date                            Name
63.1K       Jul 22 04:40                    /var/log/authd_sdb.log.0.gz
248.5K      Nov 22 12:17                    /var/log/chassisd.0.gz
60.2K       Dec 18 11:31                    /var/log/clicommand.0.gz
277.5K      Oct 23 16:15                    /var/log/clicommand.1.gz
<snipped>

lab@MX80-a> request system storage cleanup dry-run

List of files to delete:

Size Date Name

63.1K Jul 22 04:40 /var/log/authd_sdb.log.0.gz

248.5K Nov 22 12:17 /var/log/chassisd.0.gz

60.2K Dec 18 11:31 /var/log/clicommand.0.gz

277.5K Oct 23 16:15 /var/log/clicommand.1.gz

You can find many large files, especially under the /var/sw/pkg folder. During the Junos upgrade, the system will place a backup copy of the installation package under the /var/sw/pkg folder:

lab@MX80-a> file list /var/sw/pkg detail 

/var/sw/pkg:
total blocks: 1617740
-rw-r--r-- 1 root wheel 138921158 Sep 14 14:09 jbundle-ppc-10.3R1.9.tgz
-rw-r--r-- 1 root wheel 137224120 Sep 14 14:43 jbundle-ppc-10.3R4.4.tgz
-rw-r--r-- 1 root wheel 127618347 Sep 21 11:16 jbundle-ppc-12.2R1.8.tgz
-rw-r--r-- 1 root wheel 145973437 Sep 14 14:01 jinstall-ppc-10.3R1.9-domestic-signed.tgz
-rw-r--r-- 1 root wheel 144286989 Sep 14 14:37 jinstall-ppc-10.3R4.4-domestic-signed.tgz
-rw-r--r-- 1 root wheel 133832306 Sep 21 11:08 jinstall-ppc-12.2R1.8-domestic-signed.tgz
-rw-r--r-- 1 root wheel 109 Sep 21 11:16 rollback
total files: 7

lab@MX80-a> file list /var/sw/pkg detail

/var/sw/pkg:

total blocks: 1617740

-rw-r--r-- 1 root wheel 138921158 Sep 14 14:09 jbundle-ppc-10.3R1.9.tgz

-rw-r--r-- 1 root wheel 137224120 Sep 14 14:43 jbundle-ppc-10.3R4.4.tgz

-rw-r--r-- 1 root wheel 127618347 Sep 21 11:16 jbundle-ppc-12.2R1.8.tgz

-rw-r--r-- 1 root wheel 145973437 Sep 14 14:01 jinstall-ppc-10.3R1.9-domestic-signed.tgz

-rw-r--r-- 1 root wheel 144286989 Sep 14 14:37 jinstall-ppc-10.3R4.4-domestic-signed.tgz

-rw-r--r-- 1 root wheel 133832306 Sep 21 11:08 jinstall-ppc-12.2R1.8-domestic-signed.tgz

-rw-r--r-- 1 root wheel 109 Sep 21 11:16 rollback

total files: 7

Usually, this will not be a issue, when the system storage has enough space. But, for the MX80 platform, the /var file system has only about 3GB of total space. When there are a lot of backup installation packages, the free space will be relatively low. As these are only backup package files, you can delete these files to free up more disk space:

lab@MX80-a> file delete /var/sw/pkg/j* 

lab@MX80-a> file list /var/sw/pkg 

/var/sw/pkg:
rollback

lab@MX80-a> file delete /var/sw/pkg/j*

lab@MX80-a> file list /var/sw/pkg

/var/sw/pkg:

rollback

Now you will have enough free disk space:

lab@MX80-a> show system storage 
Filesystem         Size       Used      Avail      Capacity       Mounted on
/dev/da0s1a        885M       122M      692M       15%            /
devfs              1.0K       1.0K      0B         100%           /dev
/dev/md0           41M        41M       0B         100%           /packages/mnt/jbase
/dev/md1           178M       178M      0B         100%           /packages/mnt/jkernel-ppc-12.2R1.8
/dev/md2           34M        34M       0B         100%           /packages/mnt/jpfe-MX80-12.2R1.8
/dev/md3           6.5M       6.5M      0B         100%           /packages/mnt/jdocs-12.2R1.8
/dev/md4           54M        54M       0B         100%           /packages/mnt/jroute-ppc-12.2R1.8
/dev/md5           12M        12M       0B         100%           /packages/mnt/jcrypto-ppc-12.2R1.8
/dev/md6           2.8G       10.0K     2.6G       0%             /tmp
/dev/md7           2.8G       11M       2.6G       0%             /mfs
/dev/da0s1e        98M        272K      90M        0%             /config
procfs             4.0K       4.0K      0B         100%           /proc
/dev/da1s1f        2.8G       1.4G      1.2G       53%            /var