Determining the Source of a Given File System Mount on Unix [migrated]
- by phobos51594
Background
Recently I have run into a bit of a snag on my home FreeBSD server. I recently upgraded it to the latest stable release, and I have noticed some strange behavior with the /var partition. Originally, I had the system configured such that /var had its own partition with /var/run and /var/log in memory disks (/tmp, too).
After the upgrade, I notice there is a new, fourth memory disk mounting directly to /var that I had not set up manually and is not in my fstab. It is only 28 megs or so in size and is causing problems when trying to update my ports collection. The ramdisk mounts atuomagically at boot and cannot be unmounted while in multi-user mode. If I drop to single user mode, I am able to unmount it without issue, however rebooting causes it to pop right back up.
System specifications have been included at the end of the post.
Question
Is there any way to determine exactly what is mounting a given memory disk (or any filesystem, for that matter) after it has been mounted?
Alternately, does anybody have any ideas what might have caused the new /var ramdisk to pop up?
System Specification
# uname -a
FreeBSD sarge 9.1-PRERELEASE FreeBSD 9.1-PRERELEASE #0: Thu Nov 22 14:02:13 PST 2012 donut@sarge:/usr/obj/usr/src/sys/GENERIC i386
# df
Filesystem 1K-blocks Used Avail Capacity Mounted on
/dev/da0s1a 515612 410728 63636 87% /
devfs 1 1 0 100% /dev
/dev/da0s1d 515612 287616 186748 61% /var
/dev/da0s1e 6667808 2292824 3841560 37% /usr
/dev/md0 63004 32 57932 0% /tmp
/dev/md1 3484 8 3200 0% /var/run
/dev/md2 31260 8 28752 0% /var/log
/dev/md3 31260 512 28248 2% /var <-- This
# cat /etc/fstab
# Device Mountpoint FStype Options Dump Pass#
/dev/da0s1a / ufs rw,noatime 1 1
/dev/da0s1d /var ufs rw,noatime 2 2
/dev/da0s1e /usr ufs rw,noatime 2 2
md /tmp mfs rw,-s64M,noatime 0 0
md /var/run mfs rw,-s4M,noatime 0 0
md /var/log mfs rw,-s32M,noatime 0 0
Thank you in advance for any assistance.
