Unexpected result of partial disk restore
Posted: Sun Jun 23, 2019 8:54 pm
There has been a lot of discussion recently about restoring a system to new hardware. Someone was told, I think, to do a full disk backup and later, if necessary, do a full disk restore to a new disk.
This got me thinking. I don't typically do a full disk backup. I back up my BIBM partition, my Windows partition and an extended partition containing two data volumes. I specifically don't include a copy of the Windows partition or another currently unused large primary partition. The point here is that the partitions that are included are all explicitly specified as individual partitions.
I have always considered my backup to have two purposes: 1) Restoration of the Windows partition in the case of a botched update or bad software install or something and 2) backup of data which can be restored to new hardware or a new Windows install.
I've always expected that in case of disk failure, I'd have to re-install Windows and applications.
The above mentioned discussions made me decide to do a test without any expectation of getting the results I did.
I first made a whole disk backup which I expected to use to recover from my failed tests.
I then deleted all partitions except the Windows partition and converted the disk to GPT just to have something significantly different than the normal state of the disk. After verifying that this GPT disk booted, I used Partition Work to delete the Windows partition and noted that Partition Work still claimed to be listing GPT partitions even though there weren't any.
Then I restored my normal backup described above specifying full disk, whole disk or whatever it is noting that partial disk was indicated.
To my amazement, after the restore completed, Partition Work indicated that it was listing EMBR partitions and booting caused booting of BIBM and Windows 10.
Even though I explicitly backed up individual partitions, clearly(?) something other than those partitions was backed up and restored.
This got me thinking. I don't typically do a full disk backup. I back up my BIBM partition, my Windows partition and an extended partition containing two data volumes. I specifically don't include a copy of the Windows partition or another currently unused large primary partition. The point here is that the partitions that are included are all explicitly specified as individual partitions.
I have always considered my backup to have two purposes: 1) Restoration of the Windows partition in the case of a botched update or bad software install or something and 2) backup of data which can be restored to new hardware or a new Windows install.
I've always expected that in case of disk failure, I'd have to re-install Windows and applications.
The above mentioned discussions made me decide to do a test without any expectation of getting the results I did.
I first made a whole disk backup which I expected to use to recover from my failed tests.
I then deleted all partitions except the Windows partition and converted the disk to GPT just to have something significantly different than the normal state of the disk. After verifying that this GPT disk booted, I used Partition Work to delete the Windows partition and noted that Partition Work still claimed to be listing GPT partitions even though there weren't any.
Then I restored my normal backup described above specifying full disk, whole disk or whatever it is noting that partial disk was indicated.
To my amazement, after the restore completed, Partition Work indicated that it was listing EMBR partitions and booting caused booting of BIBM and Windows 10.
Even though I explicitly backed up individual partitions, clearly(?) something other than those partitions was backed up and restored.