Role of empty /rpool/ROOT/pve-1 dir ?

[RolandK]

Hello,

can someone explain the role/purpose of /rpool/ROOT/pve-1 directory ?

while learning zfs, i came across this and i always wondered, what this directory means or is all about. to be honest, it confused me a little bit.

ok, there is that dataset rpool/ROOT/pve-1 and it's mounted as "/", and /rpool/ROOT/pve-1 is the original/initial mountpoint

but - if i create another dataset rpool/ROOT/pve-2 and set mountpoint to /mnt/pve-2 , there is no directory /rpool/ROOT/pve-2 left, so it looks like /rpool/ROOT/pve-1 is just an orphan which can/should better be deleted !?

 

[RolandK]

oh, and by the way , that should better be "dataset" or "filesystem", not volume in those proxinstall error messages.

a volume or zfs volume (zvol) is something different.

# grep -r zfspoolname . |grep volume ./proxinstall: die "unable to create zfs $zfspoolname/ROOT volume\n"; ./proxinstall: die "unable to create zfs $zfspoolname/data volume\n"; ./proxinstall: die "unable to create zfs $zfspoolname/ROOT/$zfsrootvolname volume\n";

 

[UdoB]

Good mornin,

on a fresh system of mine "pve-1" contains the root-Filesystem and it is mounted to "/":

~# zfs list rpool/ROOT/pve-1
NAME               USED  AVAIL     REFER  MOUNTPOINT
rpool/ROOT/pve-1  4.37G   851G     4.37G  /

~# mount | grep pve-1
rpool/ROOT/pve-1 on / type zfs (rw,relatime,xattr,noacl)

When I create a new data-set it is mounted automatically:

~# zfs create rpool/ROOT/pve-test
~# zfs list rpool/ROOT/pve-test
NAME                  USED  AVAIL     REFER  MOUNTPOINT
rpool/ROOT/pve-test    96K   851G       96K  /rpool/ROOT/pve-test

~# mount | grep pve-test
rpool/ROOT/pve-test on /rpool/ROOT/pve-test type zfs (rw,relatime,xattr,noacl)

IF it is being mounted is crontrolled by some properties:

~# zfs get all  rpool/ROOT/pve-1 | grep mount
rpool/ROOT/pve-1  mounted               yes                    -
rpool/ROOT/pve-1  mountpoint            /                      local
rpool/ROOT/pve-1  canmount              on                     default

Best regards

 

[RolandK]

yes, but what do you want to tell me ?

i'm asking what's the purpose of a directory which apparently has no purpose, which is no mountpoint and which probably should not exist at all.

it's confusing.

if your /dev/sdb is mounted to /mnt/usb-stick , wouldn't you wonder/ask when there is an empty/orphan /mnt/sdb ? would you leave it there?

/rpool/ROOT/pve-1 is the default mountpoint of rpool/ROOT/pve-1 and that is normally getting removed when moving the zfs mount to a different location.

so why does this mountpoint still exist in every proxmox installation ?

can it safely being deleted ?

i'm also asking because if want to learn more on zfs.

 

[UdoB]

yes, but what do you want to tell me ?

it's confusing.

I just stated what a zfs-only install looks like - on my machine. ;-)

Probably I would delete it because it is obviously not used, and I would not expect problems. But I am not in a position to guarantee this...!

 

[RolandK]

i'd be curious why it exists at all. i tried to find that out, but via looking at proxmox installer source, i get no clue...