df command does not show LVM disk space

guertin · 09-09-2013, 07:33 AM

I've got a Fedora 19 box, with the local root and swap partitions managed with LVM. Everything works fine, but if I want to see how much space is available, "df" does not show the LVM volumes, only the local boot partition:

Quote:

# df -hl
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 477M 100M 348M 23% /boot

Here are the outputs of pvs, vgs, and lvs, just to confirm that everything there looks normal:

Quote:

# pvs
PV VG Fmt Attr PSize PFree
/dev/sda5 VolGroup lvm2 a-- 115.09g 672.00m

Quote:

# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup 1 2 0 wz--n- 115.09g 672.00m

Quote:

# lvs
LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert
lv_root VolGroup -wi-ao--- 104.75g
lv_swap VolGroup -wi-ao--- 9.69g

Just as a shot in the dark, I tried re-resizing the filesystem on the volume, but that did nothing:

Quote:

# resize2fs /dev/VolGroup/lv_root
resize2fs 1.42.7 (21-Jan-2013)
The filesystem is already 27459584 blocks long. Nothing to do!

What's going on? How can I make the LVM volumes show up with df?

zhjim · 09-09-2013, 07:46 AM

df only shows info for mounted filesystems.

guertin · 09-09-2013, 08:11 AM

Quote:

Originally Posted by zhjim

df only shows info for mounted filesystems.

This is the root filesystem. It is mounted. :-)

Quote:

/etc/fstab:

/dev/mapper/VolGroup-lv_root / ext4 defaults 1 1
/dev/sda3 /boot ext4 defaults 1 2
/dev/mapper/VolGroup-lv_swap swap swap defaults 0 0

Quote:

# mount /
mount: /dev/mapper/VolGroup-lv_root is already mounted or / busy

Quote:

# df -hl
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 477M 100M 348M 23% /boot

guertin · 09-09-2013, 09:07 AM

Quote:

Originally Posted by guertin

This is the root filesystem. It is mounted. :-)

Although, now that I think of it, it doesn't show up with the mount command, either:

Quote:

# mount
sysfs on /sys type sysfs (rw)
/dev/sda3 on /boot type ext4 (rw)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
vmware-vmblock on /var/run/vmblock-fuse type fuse.vmware-vmblock (rw,nosuid,nodev,default_permissions,allow_other)
<plus a few NFS-mounted systems>

Edit: Though it is present in /proc/mounts:

Quote:

# cat /proc/mounts
rootfs / rootfs rw 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
<snip>
/dev/mapper/VolGroup-lv_root / ext4 rw,relatime,data=ordered 0 0
<snip>
/dev/sda3 /boot ext4 rw,relatime,data=ordered 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
vmware-vmblock /var/run/vmblock-fuse fuse.vmware-vmblock rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other 0 0

So, I guess I should amend my problem to: a mounted LVM volume does not show with either the df or mount commands.

guertin · 09-09-2013, 09:33 AM

OK, one more interesting tidbit. If I try "mount -va":

Quote:

# mount -va
/ : ignored
/boot : already mounted
swap : ignored
/dev/shm : successfully mounted
mount: devpts is already mounted or /dev/pts busy
/sys : already mounted
mount: proc is already mounted or /proc busy

The / and swap volumes are ignored. Why "ignored" instead of "already mounted", as with /boot and /sys?

zhjim · 09-09-2013, 09:51 AM

I have no idea what so ever. Running mount v.2.20.1 and df v.8.13 on debian both print info about my root parition. Mount -av also gives as you predicted already mounted error.