Why might a partition show up in `mount` but not `df`?
If I compare this
$> sudo mount | grep sdb
/dev/sdb1 on /windows type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096)
/dev/sdb2 on /store type ext4 (rw)
with this
$> sudo df -h | grep sdb
/dev/sdb1 94G 59G 35G 63% /windows
I see /dev/sdb2 is missing. But if I run this:
$> df -h /dev/sdb2
Filesystem Size Used Avail Use% Mounted on
/dev/sdb2 367G 342G 6.2G 99% /store
It's there. Why might this be happening?
I do not have a /etc/udev/rules.d/99-hide-disks.rules
file. Also note
$> grep store /etc/fstab
# /store was on /dev/sdb3 during installation
UUID=760630a7-223f-42e4-aecf-de92e32f12b9 /store ext4 defaults 0 2
Full output of df
:
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda5 14287344 7560960 5977584 56% /
none 4 0 4 0% /sys/fs/cgroup
udev 8140000 8140000 0 100% /dev
tmpfs 1631016 68292 1562724 5% /run
none 5120 4 5116 1% /run/lock
none 8155080 23212 8131868 1% /run/shm
none 102400 24 102376 1% /run/user
/dev/sda7 73385208 4711820 64922580 7% /home
/dev/sdb1 97650684 61264484 36386200 63% /windows
/dev/sda2 97280 32492 64788 34% /boot/efi
/store/var/tmp 384466988 357170340 7743728 98% /var/tmp
/home/me/.Private 73385208 4711820 64922580 7% /home/me
Full output of mount
:
/dev/sda5 on / type ext4 (rw,noatime,errors=remount-ro,discard)
proc on /proc type proc (rw,nodev,noexec,nosuid)
sysfs on /sys type sysfs (rw,nodev,noexec,nosuid)
none on /sys/fs/cgroup type tmpfs (rw,uid=0,gid=0,mode=0755,size=1024)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
none on /sys/firmware/efi/efivars type efivarfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,nodev,noexec,nosuid,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,nodev,noexec,nosuid,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)
none on /dev/.bootchart/proc type proc (rw,relatime)
/dev/sda7 on /home type ext4 (rw,noatime,discard)
/dev/sdb1 on /windows type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096)
/dev/sda2 on /boot/efi type vfat (rw)
/dev/sdb2 on /store type ext4 (rw)
/store/tmp on /tmp type none (rw,bind)
/store/var/tmp on /var/tmp type none (rw,bind)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,nodev,noexec,nosuid)
systemd on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,noexec,nodev,none,name=systemd)
/home/.ecryptfs/me/.Private on /home/me
Solution 1:
The reason why
sudo df -h | grep sdb
did not output any line related to sdb2
on your system is because the output of sudo df -h
did not contain any reference to sdb2
. To verify this, look through the output of df -h
manually. There is a reference to sdb1
and to /store/var/tmp
, but nothing about sdb2
. (It is only listed when /dev/sdb2
is provided explicitly as an argument to df
, as in your third code snippet.) This is technically the question you asked.
Implicit in the question is also why df -h
does not output a line related to /dev/sdb2
when it clearly is mounted. To find that out would require more information about your system; for example, see this 2014 bug report for Red Hat explaining that changes in /etc/mtab
can create duplicates that df
tries to reduce. This could cause mounted partitions not to surface.