I have a 3 x 1 TB mirror-0 array, and I'm migrating the data to a second 2 x 2 TB mirror-0 array, using rsync.
The only differences between the mirrors are:
1. The version of FreeBSD which created it (FreeBSD 10.4-STABLE versus FreeBSD 12.0-STABLE). Note that the original array has had "zpool upgrade" done since moving to 12.0-STABLE.
2. The logical size of the array (1TB versus 2TB)
3. The ashift value (ashift=9 versus ashift=12)
4. The use of different partitioning schemes (MBR adaXs1 versus GPT adaXp1)
This is how it looks once the data is copied:
The two arrays have identical compressatio/logicalused/localreferenced values (as expected, since the data is the same), but for some reason the new array consumes an extra 312GB (about +46%) of space.
I know that ashift=12 will result in less free space, but I don't believe the penalty should be this large?
Any ideas? Thank you.
The only differences between the mirrors are:
1. The version of FreeBSD which created it (FreeBSD 10.4-STABLE versus FreeBSD 12.0-STABLE). Note that the original array has had "zpool upgrade" done since moving to 12.0-STABLE.
2. The logical size of the array (1TB versus 2TB)
3. The ashift value (ashift=9 versus ashift=12)
4. The use of different partitioning schemes (MBR adaXs1 versus GPT adaXp1)
This is how it looks once the data is copied:
Code:
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
db 928G 673G 255G - - 75% 72% 1.00x ONLINE -
dbnew 1.81T 985G 871G - - 0% 53% 1.00x ONLINE -
NAME PROPERTY VALUE SOURCE
db used 673G -
db referenced 673G -
db compressratio 2.11x -
db logicalused 1.37T -
db logicalreferenced 1.37T -
NAME PROPERTY VALUE SOURCE
dbnew used 985G -
dbnew referenced 985G -
dbnew compressratio 2.11x -
dbnew logicalused 1.37T -
dbnew logicalreferenced 1.37T -
The two arrays have identical compressatio/logicalused/localreferenced values (as expected, since the data is the same), but for some reason the new array consumes an extra 312GB (about +46%) of space.
I know that ashift=12 will result in less free space, but I don't believe the penalty should be this large?
Any ideas? Thank you.