Change volume size? DD command?

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Albert Yang

Member
Oct 26, 2017
72
1
8
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Hi

I was wondering if someone could shed some light on the issue im having, Currently I have proxmox running ZFS, i realized an issue as the VM storage shows differently from the host itself

on the vm storage shows


data 6.8T 4.5T 2.4T 66% /data
but on the zfs pool of that disks shows this, meaning that using 4.5tb really but its showing 8.57tb double space

rpool/data/vm-146-disk-1 8.57T 1.59T 8.57T -
then i realized the disk using 8k volblocksize, reading a bit seems that the lower the blocksize the better speeds but it seems to double the size of space. (correct me if im wrong)

So i read a bit that having the 16k blocksize or 32k is acceptable as its a storage

Then reading a bit more i would need to create another vm disk and DD

So im confused on how i can fix the blocksize, not sure if these steps would be correct?

would i first edit the storage.config and add this

zfspool: local-zfs
pool rpool/data
content rootdir,images
blocksize 32k
sparse 1
then on the webgui create the new disk and should give the block size i need

but im lost on the DD i didnt know that zfs pools can be DD normally dont they use zfs send or receive? but i guess in this case its within the same pool so not sure what the process here?

Thank you
 

dandanio

Active Member
Oct 10, 2017
182
70
28
Do you have compression or deduplication turned on? Or use snapshots? That would explain the hidden space usage.
# zfs list -t snapshot
and
# zfs get all | grep -E 'compressratio|dedup'
8k with large files (as vmdks are) is really not that significant.
 

Albert Yang

Member
Oct 26, 2017
72
1
8
30
Thanks for the reply only have 2 snapshots before messing up with the disk
root@pve:~# zfs list -t snapshot
NAME USED AVAIL REFER MOUNTPOINT
rpool/data/vm-146-disk-0@beforefixspace 664M - 49.6G -
rpool/data/vm-146-disk-1@beforefixspace 469M - 8.57T -

root@pve:~# zfs get all | grep -E 'compressratio|dedup'
rpool compressratio 1.03x -
rpool dedup off default
rpool refcompressratio 1.00x -
rpool/ROOT compressratio 1.07x -
rpool/ROOT dedup off default
rpool/ROOT refcompressratio 1.00x -
rpool/ROOT/pve-1 compressratio 1.07x -
rpool/ROOT/pve-1 dedup off default
rpool/ROOT/pve-1 refcompressratio 1.07x -
rpool/data compressratio 1.03x -
rpool/data dedup off default
rpool/data refcompressratio 1.00x -
rpool/data/vm-146-disk-0 compressratio 1.20x -
rpool/data/vm-146-disk-0 dedup off default
rpool/data/vm-146-disk-0 refcompressratio 1.20x -
rpool/data/vm-146-disk-0@beforefixspace compressratio 1.20x -
rpool/data/vm-146-disk-0@beforefixspace refcompressratio 1.20x -
rpool/data/vm-146-disk-1 compressratio 1.03x -
rpool/data/vm-146-disk-1 dedup off default
rpool/data/vm-146-disk-1 refcompressratio 1.03x -
rpool/data/vm-146-disk-1@beforefixspace compressratio 1.03x -
rpool/data/vm-146-disk-1@beforefixspace refcompressratio 1.03x -
rpool/data/vm-146-state-beforefixspace compressratio 1.29x -
rpool/data/vm-146-state-beforefixspace dedup off default
rpool/data/vm-146-state-beforefixspace refcompressratio 1.29x
-