But this WAS my backup!

February 22, 2009 3:02 PM

How can I repair any broken files resulting from power loss during defragmentation? It seems that most file recovery applications want to move everything to a new disk, but this is not a good option for me because I don't have any other drives large enough. I was using iDefrag on my terabyte (My Book) external hard drive. It had gotten almost 21 hours in, and somehow the power cable got unplugged and the battery died. To make a long story short, iDefrag can't see the disk at all, Disk Utility sees the hard drive but not any of the data or the partition itself, and verify and repair are not selectable.

So this is
Mac OS 10.5.6, Macbook Pro, My Book 1tb external hard drive, iDefrag.

Why would you defrag an HFS+ external hard drive, you ask? I'm about to set up Boot Camp, and I want some extra space for Windows-compatible storage, but it won't make an NTFS partition because the free space isn't consecutive.

I have a feeling that there isn't much to repair, and all the data (including backups of every computer in the house, including some long since reformatted, as well as my 30gb+ iTunes library that I just moved there) should still be there, I just don't know how to make anything see the hard drive in the first place.

I do have access to another My Book 1tb (this one is NTFS), but I don't know if it would have enough free space either (and it's my dad's)

posted by N2O1138 to computers & internet (6 comments total)

Looking through the other applications on my boot disk, Diskwarrior sounds like it might do what I need, but I'm hesitant because it could possibly make things worse. Can anyone recommend it (or confirm my suspicions)?
posted by N2O1138 at 3:13 PM on February 22, 2009

1. Go to a big-box store that sells hard drives and buy one.
2. Use it as a restore target. Then wipe the old backup and transfer back to that.
3. Wipe the new hard drive and return it.

For whatever it's worth, OS X has a built-in file defragging feature.
posted by adamrice at 3:49 PM on February 22, 2009

To do this using normal recovery tools, you really do need a drive that's larger than the one you're trying to fix. The imaging tool needs to copy everything because: 1) it's safer to do the work on a copy, and 2) before it finds your files, it can't tell which parts of your disk are free and which actually contain recoverable info.
posted by zippy at 4:30 PM on February 22, 2009

Diskwarrior won't make things worse. I think it might be exactly what you need. In any case, Diskwarrior allows you to mount a preview of what your repaired disk will look like before you commit any repairs to disk.
posted by pmbuko at 7:12 PM on February 22, 2009

Diskwarrior seems to have worked perfectly! It didn't take very long either (maybe 20-25 minutes)
posted by N2O1138 at 7:46 PM on February 22, 2009

Glad you got it fixed but I should point out that it's not a backup if it's the only copy of the data, simply because it's on an external drive. Anything you don't want to lose should be on two different physical drives at the least.
posted by 6550 at 8:35 AM on February 23, 2009