zfs send | zfs receive

For the record, I was doing a copy within a system recently:

# time zfs send storage/bacula@transfer | mbuffer | zfs receive storage/compressed/bacula-buffer
in @  0.0 kB/s, out @  0.0 kB/s, 4394 GB total, buffer 100% fullll
summary: 4394 GByte in 35 h 11 min 35.5 MB/s

real    2111m18.302s
user    11m44.831s
sys     258m59.151s

I was copying my Bacula Volumes from non-compressed ZFS to compressed ZFS.

# zfs list
NAME                                USED  AVAIL  REFER  MOUNTPOINT
storage                            7.12T  1.76T  1.75G  /storage
storage/bacula                     4.87T  1.76T  4.29T  /storage/bacula
storage/compressed                 2.25T  1.76T  46.9K  /storage/compressed
storage/compressed/bacula-mbuffer  2.25T  1.76T  2.25T  /storage/compressed/bacula-mbuffer
storage/pgsql                      5.50G  1.76T  5.50G  /storage/pgsql

The size taken went from 4.87T to 2.25T, for more than 50% compression. I’m happy with that.

However the throughput wasn’t great. However:

• The same HDD were reading and writing
• compression is a factor
• I only do this once

However, if it’s going go take me 35 hours to copy my backups, that’s a long time without backups. But I do think I’ll be able to take advantage of ZFS snapshot somehow. The initial copy was based upon a snapshot.