GPT disks not aligned as documented

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GPT disks not aligned as documented

Postby TAC109 » Thu Feb 09, 2017 5:06 pm

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.
TAC109
 
Posts: 215
Joined: Tue Sep 06, 2011 3:41 pm

Re: GPT disks not aligned as documented

Postby TeraByte Support » Fri Feb 17, 2017 6:43 am

it's the default as documented. you'd look at a partinfo listing to
determine the alignment. hanging on disk io in ifl and then chkdsk in
winodws would point to something else since alignment wouldn't cause hangs.

"Tom Cole" wrote in message news:13279@public.image...

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.

TeraByte Support
 
Posts: 2313
Joined: Thu May 05, 2011 3:37 pm

Re: GPT disks not aligned as documented

Postby TAC109 » Tue Feb 28, 2017 6:54 pm

Yes I agree that it is not an alignment problem.

I have repeated the original resize with 'align on 1MiB boundaries' checked and unchecked many times and determined that the lockup occurs randomly at different times with no obvious cause. The lockup always occurs on the last phase of the resize when IFL would normally be doing the final check.

I have attached a photo showing the IFL lockup.

To eliminate possible hardware problems I have run MemTest86 overnight on this machine with 0 errors reported. I have also run a few IFL full backups with verify byte-for-byte switched on and these have completed successfully.

Note that I am using the x64 version of IFL as this is the only version that will load on my SP4.
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TAC109
 
Posts: 215
Joined: Tue Sep 06, 2011 3:41 pm

Re: GPT disks not aligned as documented

Postby TeraByte Support » Tue Feb 28, 2017 9:00 pm

have you left it, could be just the ui.

"TAC109" wrote in message news:13315@public.image...

Yes I agree that it is not an alignment problem.

I have repeated the original resize with 'align on 1MiB boundaries' checked
and unchecked many times and determined that the lockup occurs randomly at
different times with no obvious cause. The lockup always occurs on the last
phase of the resize when IFL would normally be doing the final check.

I have attached a photo showing the IFL lockup.

To eliminate possible hardware problems I have run MemTest86 overnight on
this machine with 0 errors reported. I have also run a few IFL full backups
with verify byte-for-byte switched on and these have completed successfully.

Note that I am using the x64 version of IFL as this is the only version that
will load on my SP4.

TeraByte Support
 
Posts: 2313
Joined: Thu May 05, 2011 3:37 pm

Re: GPT disks not aligned as documented

Postby TAC109 » Tue Feb 28, 2017 10:08 pm

I had 'left it' for a minute or two many times. Nothing. Had to reboot by
holding down the power button for 10 seconds.

TeraByte Support wrote:
> have you left it, could be just the ui.
>
> "TAC109" wrote in message news:13315@public.image...
>
> Yes I agree that it is not an alignment problem.
>
> I have repeated the original resize with 'align on 1MiB boundaries' checked
> and unchecked many times and determined that the lockup occurs randomly at
> different times with no obvious cause. The lockup always occurs on the last
> phase of the resize when IFL would normally be doing the final check.
>
> I have attached a photo showing the IFL lockup.
>
> To eliminate possible hardware problems I have run MemTest86 overnight on
> this machine with 0 errors reported. I have also run a few IFL full backups
> with verify byte-for-byte switched on and these have completed successfully.
>
> Note that I am using the x64 version of IFL as this is the only version that
> will load on my SP4.



TAC109
 
Posts: 215
Joined: Tue Sep 06, 2011 3:41 pm


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