PDA

View Full Version : SD confused about volume names after breaking RAID config?


xochi
11-30-2006, 01:34 PM
I have a weird situation : Normally, SD remembers the last copy settings when you restart it (source volume, destination volume, and options). However in some cases it seems to have trouble remembering the destination volume. When I start SD, it selects the source volume, but the destination volume popup is unselected (even though I can manually select the volume in the destination popup).

One possible clue -- I'm using two identical drives "Alpha" (boot drive) and "MirrorAlpha" (the backup drive). Previously, both drives were set to be part of a software RAID-1 configuration, named "Alpha". However, I was unable to boot from a RAID configuration, so I repartitioned both drives.

In fact, I've seen some messages in the console log from SD saying "Can't find destination volume 'Alpha' " -- which is weird, since the "Alpha" is the name of the SOURCE volume, not the destination.

My theory: a drive that was part of a RAID-1 set is somehow keeping it's RAID set name, instead of it's new name after being re-partitioned? Does SD use some sort of internal volume identifier rather than the volume's name? If so, might this be causing the volume name confusion? Is there any way to fix this?

dnanian
11-30-2006, 01:36 PM
Did you reformat each drive after you split the raid? They might both have the same UUID...

xochi
11-30-2006, 03:07 PM
I didn't check the UUIDs before this, so I can't say whether they were the same or different beforehand, though this is a good theory. In any case, I repartitioned the backup drive, and verified that both now have different UUIDs (shown by clicking the "Get Info" button in Disk Utility). Now it seems to work properly. Thanks!

Maybe SD should check for, and warn, if it sees drives with identical UUIDs?

dnanian
11-30-2006, 05:00 PM
We do if the source and destination have the same UUID. But some have reasons for having two drives with the same UUID...

xochi
12-01-2006, 12:15 PM
We do if the source and destination have the same UUID. But some have reasons for having two drives with the same UUID...

The actual bug I was seeing was that SD was this:

Open SD
Choose Source drive = "Alpha"
Choose Dest drive = "MirrorAlpha"
Do a backup.
Quit SD.
Restart SD.
At this point, the source drive would be selected as "Alpha" but the dest drive would be blank (even though "MirrorAlpha" was in the dest popup list, it just wasn't selected). In addition, the Console showed a message "Unable to find Dest drive 'Alpha'".

So, perhaps is there an actual bug in SD here? It seems that SD should not have mixed up "Alpha" with "MirrorAlpha" in that way. If, indeed two drives were mounted with identical UUIDs, I would argue that SD should have shown an error if the UUID was not matching the drive name that it was expecting.

dnanian
12-01-2006, 12:16 PM
We've got a logged error that it could default back to the name of the drive, but in general this is not something that happens very much, so it's got a low priority.