Why are the space values wrong?

OpenZFS
1

Hi!

Can someone explain to me why the values pertaining to space in my pool are wrong?

~$ zpool list
NAME         SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
flash_temp  3.62T  2.56T  1.07T        -         -     0%    70%  1.00x    ONLINE  -
tank        18.2T  10.2T  7.99T        -         -     5%    56%  1.00x    ONLINE  -

~$ fastfetch
# Only showing relevant info
Disk (/flash_temp): 391.05 GiB / 1.34 TiB (29%) - zfs
Disk (/flash_temp/nfsshare): 84.21 GiB / 1.04 TiB (8%) - zfs
Disk (/tank): 1.84 GiB / 6.26 TiB (0%) - zfs

I nuked the old Ubuntu Server installation I had running on my home server but forgot to do zpool export so I’ve speculated that it might be the issue why the system is reporting the wrong values - can someone confirm whether this might the issue or not?

Also, does anyone know if it’s possible to get the “real” values?

2

zpool list shows raw capacity BEFORE deducting for parity/redundancy.

Try zfs list instead.

3

Hi, Jim, and thanks for the reply.

There isn’t enough screen estate to display all the information when I run the zfs list command, due to overlay (k8s) on one of my pools. I may not have explained myself well in my original post (English isn’t my primary language), but what I meant was that certain applications, like fastfetch, don’t seem to report the “correct” values for disk space; they show the used space of the remaining free space without considering the total pool size.

For example, my pool is 18.2TB, with 56% already in use. fastfetch shows that I have used 1.84GiB/6.26TiB, instead of 10.19TiB/18.2TiB. Why doesn’t it report the “real” used space in relation to the total capacity?

4

Because they are not ZFS-aware and have no idea what the total pool capacity is; all they know is USED and FREE on each dataset. And unless you set a quota and/or refquota on a dataset, FREE for any given dataset is the same value as FREE for the pool as a whole, so there you go.