What does it mean "the volume has the wrong case sensitivity for a backup"?

Most likely the new disk needs formatting. Some are factory-formatted as case-sensitive. Macs normally don't use those. Just erase and format it as Mac OS Extended. That should allow you to use it with for your backup data.

Most likely, your backups were on a case-sensitive disk (especially if you let Time Machine format it for you). If so, the drive you copy them to must also be case-sensitive.

Click the partition (indented, under the main line for the old TM disk) via Disk Utility (in your Applications/Utilities folder). The Format is shown towards the lower left:

Format the new drive the same way. See #1 in Using Disk Utility for instructions.

Thanks for popping in. Didn't know that TM formats disks as case-sensitive.

Yeah, apparently because someone may want to back up a case-sensitve volume. We try to advise folks to format drives as case-ignorant themselves, but . . .

So, TM defaults to case-sensitive formatting? That's strange, since Macs normally don't use that for anything.😕

Yes, I understand that, but the operative word is "normally."

If TM formatted the drive as case-ignorant, and a user did backups from the OSX drive for a period of time, then wanted to also back up a case-sensitive volume, it would be impossible. The user would have to erase the drive, losing all the previous backups, or start over with a different one.

By formatting it as case-sensitive, TM can back up case-sensitive and/or case-ignorant drives.

There's only one pretty rare situation where a problem arises: if you've changed the capitalization of some names and try to restore the old versions. If the case-sensitivity on both volumes is the same, TM (actually, the Finder) gives you this prompt (one for each file, unless you check the box):

If the OSX drive is case-ignorant, and the backups are case-sensitive, however, it puts up this one:

One message only, no matter how many files there are, and no names, not even in the log. So in a few cases, involving many files, it can be a significant hassle.

As always, thanks for the lesson.

Glad this thread exists. I was having this exact problem.

Thank you for this! I was having this exact same problem. Hadn't yet thought to look at the formatting on the original drive. Thank you!

I have run into this issue as well, but unfortunately my data is too important to just format over. Did anyone find a resolution that would permit you to keep and use the backup of your data before formatting the drive?

Thanks for any help or guidance you might offer.

CR

It can probably be dealt with, but in some cases it's quite difficult and time-consuming.

What, exactly, is your situation, and how are the drives in question formatted? Are any of them network drives?

Are you trying to make backups, restore from backups, copy a set of backups, or what?

What kind of Mac do you have, and what version of OSX it is running?

iMac 27" running latest mountain lion 10.8

No network drives; seagate 1.5TB formatted case sensitive. The backups are irreplaceable since apple has deleted my original drive and data.

My primary drive was just replaced by apple under warranty. The drive hadn't failed but was one that apple had identified as a drive that was likely to fail. I am trying to restore a backup from the 1.5TB. finder sees the backups but gives me the case sensitive error when I try to restore from the drive.

I tried to copy them from this drive to the desktop but got the same error.

crichards wrote:

. . .

I am trying to restore a backup from the 1.5TB. finder sees the backups but gives me the case sensitive error when I try to restore from the drive.

How are you restoring? Are you doing a full system restore, after starting from your Recovery HD? If not, that's your best bet. See Time Machine - Frequently Asked Question #14 for instructions and the gory details.

Or are you doing something else (if so, what)?

How are your internal HD and the exernal HD formatted?

I've tried restoring both ways. Comman R on power on and by just launching tm

The internal drive is the standard Mac format. I believe it was OS extended journaled.

The external says case sensitive.

crichards wrote:

I've tried restoring both ways. Comman R on power on

And then selecting Restore From Time Machine Backup from the Utilities Menu?

If so, that should work. If that's what you're doing, are you getting the message after going through the various windows that follow that selection? If so, was it on the Select a Destination window?

and by just launching tm

That would be after setting-up a user account; and that won't do a full system restore.