ZFS raidz missing lots of disk space

H

h00bi

Member
Dec 16, 2022
34
5
13
Hello,

i have a zfs pool with raidz(1) on 5x 960GB = 4,8TB Enterprise SSD. Should be roughly 4* 960GB = 3.84TB net capacity (showing 3,71TB)
1706524392481.png

1706524431201.png

There are less than 2,8TB VM disks, no CTs
1706524463015.png

blocksize is 8k, Thin provision is disabled.
EDIT: ashift=12

When i was trying to create a 2900GB drive instead of the 2500GB drive (2.68TB in picture3) i received out of space error messages.

Where is all the space going?
Should i change block size? Usage is mostly large files.

compression is off. Which numbers might go down if i enable lz4 compression and rewrite all files? does lz4 make sense without thin provisioning?
 
Last edited:
Have a look at this: https://pve.proxmox.com/pve-docs/chapter-sysadmin.html#sysadmin_zfs_raid_considerations

h00bi said:
compression is off
Click to expand...
This is a bad idea, as ZFS will also write out all zeroes.

from man zfsprops:
When any setting except off is selected, compression will explicitly check for blocks consisting of only zeroes (the NUL byte). When a zero-filled block is detected, it is stored as a hole and not compressed using the indicated compression algorithm.
Click to expand...
 
for most of the vm disks, 16K volblocksize is shown.
1706533010026.png

Datacenter -> Storage shows this:
1706532986459.png
 
Last edited:
You must log in or register to reply here.
Top Bottom