This article explains that the /var directory is linked to /mfs/var when the hard disk is lost.
/var
/mfs/var
When the hard disk is missing, it is often incorrectly assumed that the /var directory is on the compact flash (CF) card. This article clarifies the Junos OS behavior; understanding this will help to retrieve logs from the Memory File System (MFS) file.
The /var directory is linked to /mfs/var when the hard disk is lost:
jtac@Router> show system storage Filesystem Size Used Avail Capacity Mounted on /dev/ad0s1a 851M 110M 732M 13% / devfs 1.0K 1.0K 0B 100% /dev devfs 1.0K 1.0K 0B 100% /dev/ /dev/md0 23M 23M 0B 100% /packages/mnt/jbase /dev/md1 80M 80M 0B 100% /packages/mnt/jkernel-8.5-20081017.0 /dev/md2 40M 40M 0B 100% /packages/mnt/jpfe-M320-8.5-20081017.0 /dev/md3 3.5M 3.5M 0B 100% /packages/mnt/jdocs-8.5-20081017.0 /dev/md4 28M 28M 0B 100% /packages/mnt/jroute-8.5-20081017.0 /dev/md5 8.8M 8.8M 0B 100% /packages/mnt/jcrypto-8.5-20081017.0 /dev/md6 37M 37M 0B 100% /packages/mnt/jpfe-common-8.5-20081017.0 /dev/md7 2.0G 8.0K 1.8G 0% /tmp /dev/md8 2.0G 9.0M 1.8G 0% /mfs <<<<<<<<<<<<memory proc="" procfs="" config="" ad0s1e="" dev="" disk=""> start shell % cd / % ls -al total 63 drwxr-xr-x 21 root wheel 512 Sep 13 03:09 . drwxr-xr-x 21 root wheel 512 Sep 13 03:09 .. drwxrwxr-x 2 root wheel 512 Mar 2 2009 .snap -rw-r--r-- 1 root wheel 6187 Apr 1 2007 COPYRIGHT dr-x------ 2 root wheel 512 Oct 17 2008 altconfig dr-x------ 2 root wheel 512 Oct 17 2008 altroot drwxr-xr-x 2 root wheel 512 Mar 2 2009 bin drwxr-xr-x 3 root wheel 512 Mar 2 2009 boot drwxr-xr-x 4 root wheel 512 Jan 17 06:03 config dr-x------ 2 root wheel 512 Oct 17 2008 data dr-xr-xr-x 3 root wheel 512 Sep 13 03:09 dev drwxr-xr-x 9 root wheel 2048 Jan 17 06:03 etc lrwxr-xr-x 1 root wheel 17 Mar 2 2009 kernel -> /packages/jkernel drwxr-xr-x 4 root wheel 512 Sep 13 03:09 mfs drwxr-xr-x 2 root wheel 512 Jan 12 2007 mnt drwxr-xr-x 2 root wheel 512 Mar 2 2009 modules drwxr-xr-x 3 root wheel 512 Mar 2 2009 opt drwxr-xr-x 3 root wheel 2048 Mar 2 2009 packages dr-xr-xr-x 1 root wheel 0 Jan 20 17:13 proc drwxr-xr-x 2 root wheel 512 Mar 2 2009 root drwxr-xr-x 3 root wheel 2048 Mar 2 2009 sbin lrwxrwxrwx 1 root wheel 8 Mar 2 2009 staging -> /var/tmp drwxrwxrwt 3 root wheel 512 Jan 15 14:03 tmp drwxr-xr-x 8 root wheel 512 Mar 2 2009 usr lrwxr-xr-x 1 root wheel 8 Sep 13 03:09 var -> /mfs/var <<<<<<<<<<< % cd /var/ % pwd /mfs/var <<<<<<<<<< % ls -al total 104 drwxr-xr-x 26 root wheel 512 Sep 13 03:09 . drwxr-xr-x 4 root wheel 512 Sep 13 03:09 .. drwxr-xr-x 4 root wheel 512 Sep 13 03:09 .downgrade drwxr-xr-x 2 root wheel 512 Sep 13 03:09 account drwxr-xr-x 4 root wheel 512 Sep 13 03:09 at drwxr-x--- 2 root wheel 512 Sep 13 03:09 backups drwxr-x--- 2 root wheel 512 Sep 13 03:09 crash drwxr-x--- 3 root wheel 512 Sep 13 03:09 cron drwxr-xr-x 10 root wheel 512 Jan 17 06:03 db dr-xr-xr-x 2 root wheel 512 Sep 13 03:09 empty drwxr-xr-x 6 root wheel 2048 Jan 17 06:03 etc drwx------ 2 root wheel 512 Sep 13 03:09 heimdal drwxr-xr-x 10 root wheel 512 Sep 13 03:09 home drwxr-xr-x 2 root wheel 512 Sep 13 03:09 jail drwxrwxr-x 5 root wheel 512 Sep 18 17:13 log drwxrwxr-x 2 root wheel 512 Sep 13 03:09 mail drwxr-xr-x 2 root wheel 512 Sep 13 03:09 msgs drwxr-xr-x 2 root wheel 512 Sep 13 03:09 named drwxr-xr-x 2 root wheel 512 Sep 13 03:09 preserve drwxr-xr-x 6 root wheel 2048 Jan 17 06:03 run drwxrwxr-x 2 root wheel 512 Sep 13 03:09 rwho drwxr-xr-x 2 root wheel 512 Sep 13 03:09 sdb drwxr-xr-x 7 root wheel 512 Sep 13 03:09 spool drwxrwxrwt 4 root wheel 512 Oct 22 00:16 tmp drwxr-xr-x 3 root wheel 512 Sep 13 03:09 transfer drwxr-xr-x 2 root wheel 512 Sep 13 03:09 yp % cd log % ls -al total 900 drwxrwxr-x 5 root wheel 512 Sep 18 17:13 . drwxr-xr-x 26 root wheel 512 Sep 13 03:09 .. -rw-r--r-- 1 root wheel 0 Sep 13 03:09 aprobed -rw-r----- 1 root wheel 0 Sep 13 03:09 auditd -rw-r--r-- 1 root wheel 12598 Sep 13 03:10 chassisd -rw-rw---- 1 root wheel 264481 Jan 20 17:11 cli -rw-r--r-- 1 root wheel 798 Oct 22 00:16 cosd -rw-r--r-- 1 root wheel 5870 Oct 22 00:16 dcd -rw-r--r-- 1 root wheel 0 Sep 13 03:09 dfwc -rw-r--r-- 1 root wheel 0 Sep 13 03:09 dfwd -rw-r--r-- 1 root wheel 0 Sep 13 03:09 eccd drwxr-xr-x 2 root wheel 512 Sep 13 03:09 ext drwxrwxrwt 3 root wheel 512 Sep 13 03:09 flowc drwxrwxrwt 3 root wheel 512 Sep 13 03:09 ggsn -rw-r--r-- 1 root wheel 105 Sep 13 05:17 httpd -rw-r--r-- 1 root wheel 255 Sep 13 03:10 inventory -rw-r--r-- 1 root wheel 6518 Sep 13 03:10 irsd.trace -rw-r--r-- 1 root wheel 514 Sep 13 03:10 kmd -rw-r--r-- 1 root wheel 1831 Sep 13 03:10 ksyncd -rw-r--r-- 1 root wheel 40 Sep 13 03:10 l2tpd_cfg -rw-rw---- 1 root wheel 0 Sep 13 03:10 link.up.down -rw-r--r-- 1 root wheel 98 Sep 13 03:10 lmpd -rw-r--r-- 1 root wheel 912 Sep 13 03:10 mastership -rw-rw---- 1 root wheel 31292 Jan 20 17:11 messages -rw-r--r-- 1 root wheel 320 Oct 22 00:16 pf -rw-r--r-- 1 root wheel 98 Sep 13 03:10 pgmd -rw-r----- 1 root wheel 1590 Oct 22 00:16 sampled -rwxr--r-- 1 root wheel 68422 Jan 20 14:28 smartd.trace -rw-r--r-- 1 root wheel 75 Jan 15 14:03 snapshot %