Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I've move a zfs filesystem from a pool made of a bunch or mirror vdevs to another pool made of two raidz1s with the following command

# zfs send -R pool/project@moving | zfs recv tank/project

As far as I understood the manpage, '-R' moves all the metadata as well, including the compression algorithm etc., which is exactly what I see:

# zfs get compression pool/project
NAME            PROPERTY     VALUE     SOURCE
pool/project    compression  lz4       local
# zfs get compression tank/project
NAME            PROPERTY     VALUE     SOURCE
tank/project    compression  lz4       received

So why is the the filesystem on the target pool (tank) over 20% bigger than on the source pool (pool). It's a diference of almost 6TB and I'm curious, where I lost that.

share|improve this question
    
Show the filesystem sizes, please... zfs list –  ewwhite Jul 21 at 11:30
    
Oh, you're right, 'zfs list' show actually the same size. But why does 'zpool list' show this: # zpool list NAME SIZE ALLOC FREE EXPANDSZ CAP DEDUP HEALTH ALTROOT pool 36.2T 27.9T 8.33T - 77% 1.00x ONLINE - tank 36.2T 34.7T 1.57T - 95% 1.00x ONLINE - –  Richard Pena Jul 21 at 11:57
    
Curious. Why are you moving to RAIDZ? –  ewwhite Jul 21 at 12:44

1 Answer 1

up vote 1 down vote accepted

ZFS mirrors are usually much better than RAIDZ(1/2/3) for a variety of reasons (performance, expansion, sanity). This confusion about displayed size is one of them.

Please see: Why is my RAIDZ2 pool larger than the expected size calculation?

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.