GPT disks not aligned as documented
Posted: Fri Feb 10, 2017 12:06 am
I recently used IFL Partition Work to shrink the C: partition on my
Surface Pro 4 and set up some new partitions.
Subsequently I attempted to expand the c: partition to use up some
free space and the process hung. I eventually had to do a hard power
down.
After restoring the disk from a recent backup, I booted into Windows
and ran a chkdsk, which completed OK.
I then booted to IFL and shrank the C: partition again.
Next I rebooted into Windows (booted fine) and did another chkdsk
which hung. I eventually killed the DOS window.
All the above Partition Work shrinking was done WITHOUT setting 'Align
on 1MiB boundaries'.
After restoring the disk again, I set the 'Align on 1MiB boundaries'
and was able to complete the shrinking process without further
problems. Subsequent chkdsk's completed OK.
And now comes the problem:-
According to the BootitBM manual, page 64, 'Align on 1MiB boundaries',
'GPT drives are aligned on 1MiB boundaries regardless of this option's
setting'.
The SP4 SSD is set up as a GPT disk, so the setting (or not) of this
option should not have had an effect in this case.
Surface Pro 4 and set up some new partitions.
Subsequently I attempted to expand the c: partition to use up some
free space and the process hung. I eventually had to do a hard power
down.
After restoring the disk from a recent backup, I booted into Windows
and ran a chkdsk, which completed OK.
I then booted to IFL and shrank the C: partition again.
Next I rebooted into Windows (booted fine) and did another chkdsk
which hung. I eventually killed the DOS window.
All the above Partition Work shrinking was done WITHOUT setting 'Align
on 1MiB boundaries'.
After restoring the disk again, I set the 'Align on 1MiB boundaries'
and was able to complete the shrinking process without further
problems. Subsequent chkdsk's completed OK.
And now comes the problem:-
According to the BootitBM manual, page 64, 'Align on 1MiB boundaries',
'GPT drives are aligned on 1MiB boundaries regardless of this option's
setting'.
The SP4 SSD is set up as a GPT disk, so the setting (or not) of this
option should not have had an effect in this case.