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#25612 - 04/04/13 09:34 AM DiskWarrior and Time Machine
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
This has my feathers quite ruffled at the moment. At one point Alsoft claimed DiskWarrior was "compatible" with Time Machine drives. I can't find that statement anymore. Apparently they've been called out and have pulled it for legal reasons.

Here's the rub: Since the last core rewrite (2006) they are still using COCOA and so are restricted to 32bit ram access. Therefore, when DW goes through it's rebuild process, it can only use 2gb of ram, regardless of how much actual ram (or available hdd space for vm) that your computer has. It quickly (well, if you call 20 minutes) "runs out of memory" when trying to rebuild a time machine drive that's got more than a handful of backups on it, due to the special hard links taking up a lot of memory when DW runs.

So here I sit... with a time machine drive with io errors. Finder refuses to drag and drop it without giving me a useful error message. (could not be copied... yes permissions are enabled, formats are correct, etc) so I try to run dw to fix whatever is annoying Finder, and it won't do it. Finder drag and drop is the only way I know of to copy a time machine volume, due to those funky hard links it uses. Ditto and rsync both see them as actual destination files, and even ditto quickly fills a 500gb hdd trying to copy this 160gb.

So... anyone have any suggestions for saving this time machine backup?
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#25613 - 04/04/13 10:56 AM Re: DiskWarrior and Time Machine [Re: Virtual1]
dkmarsh Online

Moderator

Registered: 08/04/09

Quote:
Since the last core rewrite (2006) they are still using COCOA and so are restricted to 32bit ram access.

I'm guessing you meant to say CARBON.
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#25615 - 04/04/13 12:38 PM Re: DiskWarrior and Time Machine [Re: Virtual1]
artie505 Online


Registered: 08/04/09
Can't help with your issue, but...

Quote:
• Repairs Time Machine backup disks
Time Machine relies on a new directory structure called a directory hard link. DiskWarrior 4 version 4.1 and later repairs damaged directory hard links and can rescue a lost Time Machine backup.

Found here.
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#25616 - 04/04/13 12:44 PM Re: DiskWarrior and Time Machine [Re: artie505]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Quote:
• Repairs Time Machine backup disks
Time Machine relies on a new directory structure called a directory hard link. DiskWarrior 4 version 4.1 and later repairs damaged directory hard links and can rescue a lost Time Machine backup.


ya. they lie. this problem is running diskwarrior 4.4, the very latest and greatest.

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#25617 - 04/04/13 01:25 PM Re: DiskWarrior and Time Machine [Re: Virtual1]
artie505 Online


Registered: 08/04/09
And this...

Quote:
August 2009
DiskWarrior 4.2
Adds Mac OS X 10.6 (Snow Leopard) compatibility and additional repair capabilities. The update is also faster than previous versions and adds compatibility with the new 64-bit kernel.

Found here.

Maybe you ought to get involved in their forum?
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#25618 - 04/04/13 01:47 PM Re: DiskWarrior and Time Machine [Re: artie505]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
I've already read some accounts of multiple people trying to get Alsoft moving on this. They haven't had any success. This isn't a new issue, it's not something they're not aware of. It's probably just more work than they want to go through.

I've personally gone through several rounds with them on another issue that's been around since version 2. (can't run DW when logged in as root) Best summary: we don't see it as an important problem, live with it.
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#25619 - 04/04/13 01:51 PM Re: DiskWarrior and Time Machine [Re: Virtual1]
artie505 Online


Registered: 08/04/09
Originally Posted By: Virtual1
I've already read some accounts of multiple people trying to get Alsoft moving on this. They haven't had any success. This isn't a new issue, it's not something they're not aware of. It's probably just more work than they want to go through.

I've personally gone through several rounds with them on another issue that's been around since version 2

I dig; I've had similar lack of success trying to deal with their tech support. frown
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#25643 - 04/06/13 08:19 AM Re: DiskWarrior and Time Machine [Re: Virtual1]
MicroMatTech3 Offline


Registered: 08/04/09
Super Duper and Apple Software Restore run in Terminal can clone a Time Machine volume.

Here is some recycled text from the old MacFixIt forums. I have not tried ASR since:


Syntax:

sudo asr restore --source /Volumes/Old\ Disk --target /Volumes/New\ Disk -erase

To make a clone of a Time Machine volume using Apple Software Restore (asr) in Terminal:

First, turn Time Machine off using the Time Machine pane of System Preferences.

Type (or better yet, copy and paste into the Terminal window) the next line:

sudo asr restore --source

Note the space character after the second “e” character in the word “restore”.

Leave a space after the “e” character in the word “source”.

Drag the icon of the original Time Machine volume to the Terminal window. The pathname is pasted in for you, followed by a space character.

Type:

--target

Leave a space after the final “t” character in the word “target”.

Drag the icon of the volume you intend to use as the new Time Machine volume to the Terminal window. THIS VOLUME WILL BE ERASED.

The pathname is pasted in for you, followed by a space character.

Type:

-erase

Press the Return key, and enter your administrative password at the prompt.

The result should be two volumes with identical names but different UUID numbers

sudo asr restore --source /Volumes/G-MINI --target /Volumes/G-Drive_Q_232 -erase


MMT3sMBPC2D:~ MMT3$ sudo asr restore --source /Volumes/G-MINI --target /Volumes/G-Drive_Q_232 -erase
Validating target...done
Validating source...done
Erase contents of /dev/disk2s2 (/Volumes/G-Drive_Q_232)? [ny]: y
Erasing target device /dev/disk2s2...done
Validating sizes...
Not enough space on /dev/disk2s2 to restore
MMT3sMBPC2D:~ MMT3$

New attempt, using the 100 GB G-Drive_Q_100 with a new, much smaller Time Machine having only 4 backups. ( I will explain why I had to make a new Time Machine later, but I urge you NOT to try to make the amount of data you need to clone smaller by deleting any Time Machine backups, either using the Finder (always an error) or the Time Machine interface. I attempted to remove one old backup from my Time Machine last night, intending to remove several more so that the entire volume would fit on G-Drive_Q_232. After a few hours, the selected backup was still there and still able to be selected, so I started the removal process again. This morning, I found that my Time Machine had folders for all of the backups. Instead of deleting the one backup, almost everything from every backup was gone. The total number of files was 70. I noticed that something was wrong when Disk Utility took about six seconds to verify the volume, and did not mention checking multi-linked files. That is because there were no links. TechTool Pro found the same result.


MMT3sMBPC2D:~ MMT3$ sudo asr restore --source /Volumes/G-MINI --target /Volumes/G-Drive_Q_100 -erase
Password:
Validating target...done
Validating source...done
Erase contents of /dev/disk2s2 (/Volumes/G-Drive_Q_100)? [ny]: y
Erasing target device /dev/disk2s2...done
Validating sizes...done
Restoring ....10....20....30....40....50....60....70....80....90....100
Verifying ....10....20....30....40....50....60....70....80....90....100
Remounting target volume...done


Copying the Time Machine volume began at 12:53 EDT and was finished at 1:57 P.M. EDT. Verification began at 1:57 EDT and was completed at 2:33 EDT. So in my example, verification took a bit more than half as long as copying.

Verifying the new volume with Disk Utility:

Verifying volume “G-MINI”
Checking Journaled HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking multi-linked files.
Checking Catalog hierarchy.
Checking Extended Attributes file.
Checking multi-linked directories.
Checking volume bitmap.
Checking volume information.
The volume G-MINI appears to be OK.
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#25691 - 04/09/13 04:08 PM Re: DiskWarrior and Time Machine [Re: MicroMatTech3]
ganbustein Offline


Registered: 08/04/09
Cloning a volume using Apple Software Restore (the asr command in Terminal) will clone any catalog damage too. If the reason you want to make the clone is to repair damage, that's not going to help.

SuperDuper will make a file-level copy, handling multi-linked files correctly, and will produce a copy without catalog damage even if the source has catalog damage. (But if the source catalog is damaged, the copy may not finish, and even if it finishes the new copy may have other non-catalog inconsistencies that make it unusable.)

As of Snow Leopard, a simple Finder drag-copy from one volume to another also correctly clones a Time Machine backup. (Same caveats as for SuperDuper. If the original has catalog damage, the copy my never finish, or may be unusable. But there will be no catalog damage in the copy even if the original had catalog damage.)

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#25692 - 04/09/13 05:09 PM Re: DiskWarrior and Time Machine [Re: ganbustein]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: ganbustein
Cloning a volume using Apple Software Restore (the asr command in Terminal) will clone any catalog damage too. If the reason you want to make the clone is to repair damage, that's not going to help.

Good point. Also related to this, most disk imaging tools will abort image creation if an IO error is encountered. That's the more frequent problem I have with time machine backup drives. People check in their machine for slowness, and I find that time machine is getting io errors or slow blocks on the TM drive when running, so it has to be replaced. Naturally people want to keep their backup history. There have been a flood of low quality (like Western Digital Passport) external 2.5" usb drives, specifically marketed as time machine backups. Those have a very high failure rate due to io errors. It's possible they're just getting handled a little more, bumped on the tables etc, and that's leading to the high failures. I think it's a combination of the two.

And related to that, I was shown a very clever idea recently. For those with a little 2.5" form factor usb or fw time machine drive and an imac, having one of those tethered to your imac (often with a 6" cable) begs for it to get bumped and knocked by keyboards, mice, etc. Apply several strips of velcro to the bottom of the case, the soft (loop) type. Then apply the hook type to the foot of the imac, between the hinge and the hole. Attach your drive. Keeps cables off the table and totally out of sight, and protects the drive. It's not going anywhere anyway.
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