my debian system is using tmfs for a few things, notably /tmp
and it's using a rather small size for it. And it's nowhere to be found in my /etc/fstab
i guess i could just add the entry in fstab and it will take effect, but i'd really like to understand what is going on.
mount:
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,relatime,size=10240k,nr_inodes=219602,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=207432k,mode=755)
/dev/disk/by-uuid/xxx on / type ext4 (rw,noatime,errors=remount-ro,user_xattr,acl,barrier=1,data=ordered)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,relatime,size=414864k)
tmpfs on /run/shm type tmpfs (rw,nosuid,nodev,relatime,size=414864k)
/dev/md0 on /DATA type ext4 (rw,noatime,errors=remount-ro,user_xattr,acl,barrier=1,data=ordered)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,nosuid,nodev,noexec,relatime)
fstab:
proc /proc proc defaults 0 0
UUID=xxx / ext4 noatime,errors=remount-ro 0 1
UUID=zzz none swap sw 0 0
/dev/md0 /DATA ext4 noatime,errors=remount-ro 0 0
I can understand /sys /proc /dev being kicked off by something else than fstab, and i can also understand the benefits of /tmp and /run being a fstmp... but where is that defined?
Where does those mounts come from?
/etc/init.d/mountoverflowtmp
which is designed to mount a tmpfs on/tmp
even when/etc/fstab
doesn't call for one in case there is very little space available on/
. It seems unlikely that this is what you are encountering (how much free space do you actually have in/
?) but can you check for that? It is the only thing that I can see in the init scripts that could be responsible for that./
. will check that script to see if there's more hints. thanks! EDIT: you're right... found this part "If root is read only, default to mounting a tmpfs on /tmp, unless one is due to be mounted from fstab." very weird behaviour... don't know why it would need /tmp before the fs checks and remount as rw.S35mountall.sh
or earlier, which comes beforeS37mountoverflowtmp
in sequence./etc/fstab
is far from the canonical place to list everything that will ever be mounted and has been for a long time.