GPT partitions not 4k aligned by 10.1-RC1 installer
Mark Martinec
Mark.Martinec+freebsd at ijs.si
Fri Oct 10 02:06:54 UTC 2014
Today I did a quick install of a 10.1-RC1 from an installation
ISO DVD. Apart from choosing a ZFS filesystem, other options were
left to their default. In particular, the align-to-4k ZFS options
was left enabled.
Guess what, the ZFS really ended up with ashift 12,
but neither the swap nor the zfs partition is 4k aligned:
# gpart show /dev/ada0
=> 34 625142381 ada0 GPT (298G)
34 1024 1 freebsd-boot (512K)
1058 8388608 2 freebsd-swap (4.0G)
8389666 616752749 3 freebsd-zfs (294G)
I find this unacceptable and surprising,
regardless of what the underlying media is.
Now that even Windows is aligning partitions to 1 MiB,
and SSD erase block is often cited as 1 MiB ...
Worried about space waste of half of one JPG photo?
Mark
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