SOLVED Accessing A Damaged Disk?

[Tannerhead]

Hi folks, thanks for any advice you can share.

I'm trying to access an external hard drive. OSX reports one of the volumes on that drive is damaged. I'd like to try to repair that volume, or wipe it clean and start over.

The obstacle is that when OSX sees that drive, it automatically reboots the entire machine. I've confirmed this by attaching the damaged external drive to a 2nd machine, where the same thing happens, automatic reboot. Thus, I can't aim Disk Utility at the damaged drive.

I have the damaged drive backed up, so it's not a crisis. But I would like to rescue that drive if possible.

I'm guessing there may be a way to turn off the automatic reboot of OSX, but if so, I don't know what that method is.

Many thanks for any advice!

 

[TonyAguila]

Hi folks, thanks for any advice you can share.

I'm trying to access an external hard drive. OSX reports one of the volumes on that drive is damaged. I'd like to try to repair that volume, or wipe it clean and start over.

The obstacle is that when OSX sees that drive, it automatically reboots the entire machine. I've confirmed this by attaching the damaged external drive to a 2nd machine, where the same thing happens, automatic reboot. Thus, I can't aim Disk Utility at the damaged drive.

I have the damaged drive backed up, so it's not a crisis. But I would like to rescue that drive if possible.

I'm guessing there may be a way to turn off the automatic reboot of OSX, but if so, I don't know what that method is.

Many thanks for any advice!

First thing to try is, with the errant drive disconnected from the Mac, restart into Safe Mode (power up and immediately hold down the Shift key). Then reconnect the drive. If this didn’t cause a reboot, you can proceed to starting Disk Utility and either try to repair it with First Aid, or simply erase it.

If successful doing either, restart normally and see if the automatic reboot is gone. If it persists, then the problem is probably a hardware fault on the part of the external drive and would probably not worth the expense of getting it fixed.

 

[Tannerhead]

Thanks a lot for the safe mode tip, much appreciated.

It looks like I won't be able to save the drive. But I am able to get the data off of it. That turned out to matter because it appears my last backup went awry and some of the files were corrupted.

So I'm off to buy another Firewire drive or two. Should you have any advice there, I'd be happy to hear it. Otherwise, thanks again, you really helped.

Have a good one!

 

[TonyAguila]

Thanks a lot for the safe mode tip, much appreciated.

It looks like I won't be able to save the drive. But I am able to get the data off of it. That turned out to matter because it appears my last backup went awry and some of the files were corrupted.

So I'm off to buy another Firewire drive or two. Should you have any advice there, I'd be happy to hear it. Otherwise, thanks again, you really helped.

Have a good one!

I would always have a dual Time Machine setup, both constantly connected and alternating backups hourly. The size would depend on how much data you have to back up, but the advantage to Time Machine is that, one, it will keep multiple versions of your data so that you can retrieve files from the day’s hourly backups, not just the newest ones, and two, it keeps daily backups of the previous days, and will automatically remove the oldest files when the drives start to run low on space.

My setup consists of two 12-terabyte hard drives because of the amount of data I keep. The initial backup onto a blank drive usually takes up close to four terabytes of space. 12 terabytes should maintain about a year and a half’s worth of backup which is good enough for me. I used to use 8-terabyte drives, but when the 12s finally earned reliability ratings equal to the 8s, I decided to switch both to 12.

When you first set up the drives, do a default erase/format. Depending on the version of macOS you are running, if you can select APFS, it will work best for TM. Do not encrypt at that point. When you first assign the drives to Time Machine, it will give you the option to do the encryption, which I recommend.

I also like redundant backups, so in addition to Time Machine, I also do regularly scheduled backups using Carbon Copy Cloner, 24/7. But if I had to make a choice, I would go with Time Machine first. And I suggest not reformatting the old drive yet. You could end up fixing it later.

Note to all users: I’m finding strange glitches in macOS Sonoma 14.1. While typing the above text, the backspace would sometimes delete multiple characters. I would have undo several times to restore previous text, so a single backspace deletes more that the last character, and the deleted characters are from several previous words/phrases. It keeps happening, even now, so please forgive any “typos” here. I may have to downgrade to 14.0, at least.

 

[Tannerhead]

Thanks much for your backup advice Tony. Your plan sounds wise. I'd be in better shape right now if I had been doing what you suggest.

I've been using SuperDuper for years, and normally it's great. In this case though, the Smart Update feature got confused in thinking there wasn't enough space on the target disk. But there would have been had SuperDuper erased the files it was supposed to erase.

I made the issue worse by trying to manually copy over the remaining files, not realizing that the failed SuperDuper backup had left the disk in a corrupted state, and I should have just wiped that disk clean and started over.

I'm shopping for new disks now, and when I get them I'll need to set up a better backup mechanism.

 

[TonyAguila]

Thanks much for your backup advice Tony. Your plan sounds wise. I'd be in better shape right now if I had been doing what you suggest.

I've been using SuperDuper for years, and normally it's great. In this case though, the Smart Update feature got confused in thinking there wasn't enough space on the target disk. But there would have been had SuperDuper erased the files it was supposed to erase.

I made the issue worse by trying to manually copy over the remaining files, not realizing that the failed SuperDuper backup had left the disk in a corrupted state, and I should have just wiped that disk clean and started over.

I'm shopping for new disks now, and when I get them I'll need to set up a better backup mechanism.

You probably got the impression that I’m passionate about backups. You also mentioned SuperDuper. I should point you towards Carbon Copy Cloner instead. Not that I don’t think SD is any good. I maintain updates of both and pay for upgrades whenever they come up. I also maintain paid updates to Chronosync and FoldersSynchronizer. CCC probably lost points to some users because when macOS started with the 2-volume scheme we are now familiar with (i.e. system and data volumes), some users could not live with having non-bootable clones. Even when CCC added the feature of being able to clone to bootable backups, I decided it was not as solid and reliable as the previous scheme.

So you may want to try the CCC approach. Clone just the data partition/volume. To do a restore, you will first create a clean volume and install macOS onto it. Then instead of proceeding with a new setup all over again, just migrate the data from the clone created with CCC. This way, you have a pristine system volume, and then all your previous data will be added to it. It might seem to be a hassle, but your macOS system will be in “brand-new” shape. I think you can get a fully functional version of CCC on a trial basis, before buying. If you like it, you can later pay for a license.

Good luck with your “new” system. Cheers!