Understand LXC container's storage size

[grobs]

Hi,

I have an LXC container that has a big storage defined in the web UI ("900G") but the filesystem seems not to have taken the last resizes commands into account.

Here is the current state of the storage:

On the container:

#df -h
Filesystem                    Size  Used Avail Use% Mounted on
rpool/data/subvol-183-disk-0   806G    643G  163G  80% /
none                           492K    4,0K  488K   1% /dev
tmpfs                           63G    200K   63G   1% /dev/shm
tmpfs                           63G    8,2M   63G   1% /run
tmpfs                          5,0M       0  5,0M   0% /run/lock
tmpfs                           63G       0   63G   0% /sys/fs/cgroup

On the Proxmox host:

# zfs list rpool/data/subvol-183-disk-0
NAME                           USED  AVAIL     REFER  MOUNTPOINT
rpool/data/subvol-183-disk-0   643G   163G      643G  /rpool/data/subvol-183-disk-0

# cat /etc/pve/local/lxc/183.conf
#production
arch: amd64
cpulimit: 0
cpuunits: 1000
hostname: xxx
memory: 24576
net0: name=eth0,bridge=vmbr2,gw=x.x.x.x,hwaddr=6A:75:2E:5D:15:79,ip=x.x.x.x/26,type=veth
onboot: 1
ostype: debian
rootfs: local-zfs:subvol-183-disk-0,size=900G
swap: 4096

# pveversion
pve-manager/6.3-6/2184247e (running kernel: 5.4.44-1-pve)

Could you please explain me that size difference (defined vs mesured)?

Regards

 

[oguz]

hi,

but the filesystem seems not to have taken the last resizes commands into account.

which command did you run to resize the disk?

 

[grobs]

I only have done it by the web UI (Resources > Resize disk).
I didn't obtain any error message.

I tried to reboot the container but notheing changed.

Other poentially interesting info: the container had a snapshot. Removing it made the container 100G larger (don't understand why).

Here is the config file before the snapshot removal:

# cat /etc/pve/local/lxc/183.conf
#production
arch: amd64
cpulimit: 0
cpuunits: 1000
hostname: xxx
memory: 24576
net0: name=eth0,bridge=vmbr2,gw=x.x.x.x,hwaddr=6A:75:2E:5D:15:79,ip=x.x.x.x/26,type=veth
onboot: 1
ostype: debian
parent: avant_reboot
rootfs: local-zfs:subvol-183-disk-0,size=900G
swap: 4096


[a_snapshot]
#
arch: amd64
cpulimit: 0
cpuunits: 1000
hostname: xxx
memory: 24576
net0: name=eth0,bridge=vmbr2,gw=x.x.x.x,hwaddr=6A:75:2E:5D:15:79,ip=x.x.x.x/26,type=veth
onboot: 1
ostype: debian
rootfs: local-zfs:subvol-183-disk-0,size=800G
snaptime: 1608128109
swap: 4096

 

[oguz]

Removing it made the container 100G larger (don't understand why).

do you see the correct size inside the container df -h after the snapshot removal?

what is the output from zfs list | grep CTID (replace CTID with yours)

 

[grobs]

do you see the correct size inside the container df -h after the snapshot removal?

No, I see 806G instead of 900G.

Before snapshot removal (I had done those commands and noted the results):

ON PROXMOX HOST :
# zfs list
NAME                           USED  AVAIL     REFER  MOUNTPOINT
rpool                          782G  62.9G      104K  /rpool
rpool/ROOT                    7.15G  62.9G       96K  /rpool/ROOT
rpool/ROOT/pve-1              7.15G  62.9G     7.15G  /
rpool/data                     775G  62.9G      144K  /rpool/data
rpool/data/subvol-108-disk-0  2.47G  3.53G     2.47G  /rpool/data/subvol-108-disk-0
rpool/data/subvol-123-disk-0  2.33G  2.67G     2.33G  /rpool/data/subvol-123-disk-0
rpool/data/subvol-125-disk-0  19.0G  19.0G     19.0G  /rpool/data/subvol-125-disk-0
rpool/data/subvol-167-disk-0  1.78G  3.22G     1.78G  /rpool/data/subvol-167-disk-0
rpool/data/subvol-183-disk-0   743G  62.9G      643G  /rpool/data/subvol-183-disk-0
rpool/data/subvol-184-disk-0  2.92G  4.08G     2.92G  /rpool/data/subvol-184-disk-0
rpool/data/subvol-197-disk-0  1.82G  9.18G     1.82G  /rpool/data/subvol-197-disk-0
rpool/data/subvol-199-disk-0  1.62G  3.38G     1.62G  /rpool/data/subvol-199-disk-0

ON CONTAINER :
# df -h
Filesystem                    Size  Used Avail Use% Mounted on
rpool/data/subvol-183-disk-0   706G    643G   63G  92% /
none                           492K    4,0K  488K   1% /dev
tmpfs                           63G    160K   63G   1% /dev/shm
tmpfs                           63G    8,2M   63G   1% /run
tmpfs                          5,0M       0  5,0M   0% /run/lock
tmpfs                           63G       0   63G   0% /sys/fs/cgroup

After snapshot removal:

ON PROXMOX HOST :
# zfs list
NAME                           USED  AVAIL     REFER  MOUNTPOINT
rpool                          682G   163G      104K  /rpool
rpool/ROOT                    7.15G   163G       96K  /rpool/ROOT
rpool/ROOT/pve-1              7.15G   163G     7.15G  /
rpool/data                     675G   163G      144K  /rpool/data
rpool/data/subvol-108-disk-0  2.47G  3.53G     2.47G  /rpool/data/subvol-108-disk-0
rpool/data/subvol-123-disk-0  2.30G  2.70G     2.30G  /rpool/data/subvol-123-disk-0
rpool/data/subvol-125-disk-0  19.0G  19.0G     19.0G  /rpool/data/subvol-125-disk-0
rpool/data/subvol-167-disk-0  1.78G  3.22G     1.78G  /rpool/data/subvol-167-disk-0
rpool/data/subvol-183-disk-0   643G   163G      643G  /rpool/data/subvol-183-disk-0
rpool/data/subvol-184-disk-0  2.92G  4.08G     2.92G  /rpool/data/subvol-184-disk-0
rpool/data/subvol-197-disk-0  1.82G  9.18G     1.82G  /rpool/data/subvol-197-disk-0
rpool/data/subvol-199-disk-0  1.62G  3.38G     1.62G  /rpool/data/subvol-199-disk-0

ON CONTAINER :
# df -h
Filesystem                    Size  Used Avail Use% Mounted on
rpool/data/subvol-183-disk-0   806G    643G  163G  80% /
none                           492K    4,0K  488K   1% /dev
tmpfs                           63G    200K   63G   1% /dev/shm
tmpfs                           63G    8,2M   63G   1% /run
tmpfs                          5,0M       0  5,0M   0% /run/lock
tmpfs                           63G       0   63G   0% /sys/fs/cgroup