Mac boot volume found corrupt - need advice on how to backup before reinstall

patto_chan

I have had my first major problem on a Mac in years. Am running 10.6.5 on a Core2Duo MacBook Pro. When I booted up today I just get a screen telling me to reboot.
I booted off the install DVD and used disk utility to try to verify/repair the boot partition.
Verify Disk stopped at "Invalid node structure. The volume OSX was found corrupt and needs to be repaired."
Repair disk stopped at: "The volume OSX could not be repaired. Disk Utility can't repair this disk. Backup as many of your files as possible, reformat the disk and restore your backed-up files."

Ugh.

On the plus side I am a regular user of Time Machine so will be able to backup nearly everything to its pre-crash state. However, there are several media files I excluded from the Time Machine backup because of their size. I would like to back them if I could before hitting the reformat/reinstall button. But the boot partition contents are no longer readable even when I boot from an external drive.
When I boot from the OS X install DVD and use Terminal I can navigate thru the folders on the boot partition leading me to believe I can still get at those files but how to effect a selective backup in this scenario? i.e. while booting off the install DVD?

Liameter

Well, the advice is a bit silly. Obviously you have to make your backup copies BEFORE you have problems. The files that you excluded from "Time Machine" need to be loaded from your alternative backup disk. If you didn't bother to make one then your only hope now is something like Data Rescue from Prosoft:
http://www.prosofteng.com/products/data_rescue.php

You must recover them onto an external Hard Drive. On the plus side, you'll be able to use this for your future backups, so it will be money well spent!

One simple fix that might work is to run "Disk Warrior":
http://www.alsoft.com/diskwarrior/

Liameter

Another point to ponder: the average life of a Hard Drive in any computer (not just Mac) is 3 years, although you might easily get 5 or more. I believe that using the HDD for recording large video files might reduce the life further.

So, even if you retrieve the files and reformat the HDD successfully, don't expect it to work reliably. I'd recommend budgeting for a replacement ASAP.

If you handle video, it's probably a good idea to use an external Firewire drive for the video files, an external USB drive for data, and use the internal one just to hold your system software and applications.

Again, this applies to ALL computers but especially to the iMac because it's so darn difficult to replace the internal HDD.

alexlyons

Recording video to the drive does not shorten it's life. No question

You're best bet to get the files back is this:

Install OS X to a separate Hard Drive, boot to that drive and get the files of your current drive, onto this new drive. This new drive should be your new boot drive, so get a size that suits you. Install it into the MBP. Then wipe the old dive.

The old drive, while unreliable, can act as a backup to these large media files if money is an issue, ideally a second new HD would be there backup.

Liameter

alexlyons wrote: »

Recording video to the drive does not shorten it's life. No question

You may be right, however recording long files causes the drive to get hotter than usual. In my experience heat reduces life of components.

alexlyons

Liameter wrote: »

You may be right, however recording long files causes the drive to get hotter than usual. In my experience heat reduces life of components.

What you're trying to say is that prolonged usage of the drive can cause it to heat up. Heat can reduce the lifetime but not always. Bottom line is you should always have a backup of anything you don't want to loose, ideally 2 or 3 with one off site.

When buying a computer, the budget for it should include whatever is needed to properly backup any important data

patto_chan

Thanks for advice. To clarify, my OS X volume won't mount and so I cannot view or transfer files using the Mac Finder even if I boot from another drive.
I have made some progress however.
With my Time Machine backup external hard drive attached I have booted off the OS X install CD. The Mac OS X Installer allows me to use other applications if required - such as Disk Utility or Terminal. Although my defunct OS X partition won't respond to Disk Utility it's file structure is still visible and navigible from within Terminal when I use those lovely Unix commands (cd, ls -lrt, cp and so on).
Therefore, using Unix commands I have accessed the directory which I had excluded from my Time Machine and selectively copied over the files I want to keep (but had excluded from my Time Machine backup schedule) to another partition on my external backup drive. Example: cd /Volumes/OSX/filepath/filename /Volumes/External_partition_name/filename
Seems to be working so far.

FWIW, this hard drive is only a year old. As per previous suggestion I swapped out the original hard last year and keep it as a permanent backup. May need to consider yet another replacement drive.