ZFS shows 42.22TiB available, but only gives the VM 25.

[Moe247365]

So bare with me. I am a quadriplegic and type with my eyes. I have 6 10tb drives in RAIDz1 I expected with formatting I would lose about 14. The VM only gets 25, please help

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~# zfs get all Movies/vm-101-disk-0
NAME                  PROPERTY              VALUE                  SOURCE
Movies/vm-101-disk-0  type                  volume                 -
Movies/vm-101-disk-0  creation              Thu May 14 12:33 2020  -
Movies/vm-101-disk-0  used                  42.2T                  -
Movies/vm-101-disk-0  available             39.6T                  -
Movies/vm-101-disk-0  referenced            2.60T                  -
Movies/vm-101-disk-0  compressratio         1.00x                  -
Movies/vm-101-disk-0  reservation           none                   default
Movies/vm-101-disk-0  volsize               25.9T                  local
Movies/vm-101-disk-0  volblocksize          8K                     default
Movies/vm-101-disk-0  checksum              on                     default
Movies/vm-101-disk-0  compression           off                    default
Movies/vm-101-disk-0  readonly              off                    default
Movies/vm-101-disk-0  createtxg             38057                  -
Movies/vm-101-disk-0  copies                1                      default
Movies/vm-101-disk-0  refreservation        42.2T                  local
Movies/vm-101-disk-0  guid                  5941070236655668434    -
Movies/vm-101-disk-0  primarycache          all                    default
Movies/vm-101-disk-0  secondarycache        all                    default
Movies/vm-101-disk-0  usedbysnapshots       0B                     -
Movies/vm-101-disk-0  usedbydataset         2.60T                  -
Movies/vm-101-disk-0  usedbychildren        0B                     -
Movies/vm-101-disk-0  usedbyrefreservation  39.6T                  -

 

[LnxBil]

Sorry, what is the question? Your volume is thick-provisioned with 25.9T.

 

[Moe247365]

Sorry, what is the question? Your volume is thick-provisioned with 25.9T.

Why does ProxMox only allow me, to give 25.9 of 42.22TiB available to the VM?

 

[fabian]

try recreating the volume with a bigger volblocksize (you can set it in the storage.cfg), it's probably the overhead caused by small volblocksize and raidZ. you probably want to tune your OS inside the VM afterwards (e.g., tell the file systems used there that they should use a bigger block size, tune databases and similar software, etc.pp.)

please also note that you should not fill up a zpool to more than about 80%, after that water mark you'll lose a lot of performance.

 

[LnxBil]

Why does ProxMox only allow me, to give 25.9 of 42.22TiB available to the VM?

As I already said: It is thick provisioned, as you can see here:

~# zfs get all Movies/vm-101-disk-0
NAME                  PROPERTY              VALUE                  SOURCE
[...]
Movies/vm-101-disk-0  refreservation        42.2T                  local
[...]
Movies/vm-101-disk-0  usedbyrefreservation  39.6T                  -

You can try to clear it by running this command:

zfs set refreservation=none Movies/vm-101-disk-0