Time Machine Verification Issue

benh78 wrote:
. . .
I still don't understand why if the Airport extreme shares the drives using the AFP protocol just like my MacMini would if I use that to share the drives.

It is quite odd, but Apple has never explained the difference. It's been that way for at least three years, so while it's possible they're working on a fix, there's no indication of it.

I do like the idea of having 2 different backup destinations e.g a shared hard drive and a portable drive that can be taken off site.

Absolutely. And it's also best to use a different app: since all hardware fails, sooner or later, and no backup app is perfect, either.

Since this thread seems to be fairly visible and ongoing, I will add my own tale of TM verification woe here!

We have three Macs: a Mac mini G4 1.42 GHz running Leopard, a MacBook 2,1 (late 2006) running Snow Leopard and a shiny new MacBook Pro 7,1 (mid-2010) Core i7 also running Snow Leopard. All have had Time Machine running since we bought a Time Capsule 500 GB about 2 years ago.

I've noticed that the problems with verification have only occurred on the two machines running Snow Leopard. The humble MM running Leopard now has over 12 months of backup history (which ironically seems to make navigating the TM interface very slow). I've had to restart TM backup three times on the MB, and as of last night, twice on the MBP. One verification failure occurred suspiciously soon after accessing the TC over the net via "Back to My Mac" (i.e. as soon as we returned home and booted up the MB). The others had no obvious cause, AFAICS - no clear temporal association with OS X updates.

My irritation is not so much the losing of data, because I know that I can archive the offending sparseimages to another disk, and I've not had problems accessing individual files. It's that it rather defeats the object of Time Machine: frequent, zero-configuration, automatic incremental backup with an intuitive GUI. And if my Mac's HD fails or my laptop is stolen between the occurrence of an error and its detection, will I be able to restore the entire system?

Here we go!

My irritation is not so much the losing of data, because I know that I can archive the offending sparseimages to another disk, and I've not had problems accessing individual files. It's that it rather defeats the object of Time Machine: frequent, zero-configuration, automatic incremental backup with an intuitive GUI.

This is exactly why I chose a Mac after 10 years of Windows. Let me restate my request @Apple:

"Let me choose via Time Machine on a backup to backup basis to direct the backup to location A or B. With an intuitive GUI." or

"Give me the possibility to put aside the offending sparseimages from the GUI instead of simply deleting them." or even better

"Repair the offending sparseimages from the GUI. I somehow can access files within in it. Should be possible to cut out error files instead of throwing away everything"

Just my 2 cents ...

Will post over at Apple Feedback.

RedGreenInBlue wrote:
. . .
I've noticed that the problems with verification have only occurred on the two machines running Snow Leopard.

Yes, the verification was added in May or so, with the 10.6.3v1.1 update, for backups done via a network, so you'll only see the message on Macs running that or later, and only when it finds a problem.

My irritation is not so much the losing of data, because I know that I can archive the offending sparseimages to another disk, and I've not had problems accessing individual files.

But you can't fix whatever's wrong, which means you cannot restore some items, and you may not be able to do a full restore.

The only real difference is, now you know when it finds a problem; on previous versions, there is no verification, so you don't know there's a problem until you try to restore something and find your backups are corrupted beyond repair.

Harald Felgner wrote:
. . .
"Give me the possibility to put aside the offending sparseimages from the GUI instead of simply deleting them."

Perhaps. But starting over means a new, full backup is required. In most cases, there isn't enough room for that, as the damaged sparse bundle is too large. And since it's damaged beyond repair . . .

"Repair the offending sparseimages from the GUI. I somehow can access files within in it. Should be possible to cut out error files instead of throwing away everything"

But that's the whole point: Disk Utility can't repair whatever it is. I've also tried +Disk Warrior+ on one, and it couldn't fix it, either.

Apple needs to prevent the problem. They never comment on such things, but it's a pretty safe bet they've got some folks working on that.

Pondini wrote:
Yes, the verification was added in May or so, with the 10.6.3v1.1 update, for backups done via a network, so you'll only see the message on Macs running that or later, and only when it finds a problem.

Hmm - yes. For some reason I had assumed that Snow Leopard was causing the problem, not revealing it - a failure of critical thinking on my part. Thanks for the clarification!

I feel increasingly inclined to get a copy of Disk Warrior. IIANM, Disk Utility isn't going to be a sensitive test for errors in the backup sparsebundle. If it were that simple, then surely Apple needn't have waited until 10.6.3 to add the verification feature to Time Machine. (Though I will now go and run Disk Utility anyway just out of curiosity...)

RedGreenInBlue wrote:
. . .
I feel increasingly inclined to get a copy of Disk Warrior.

Yes, it's probably a good investment. Often it can fix things Disk Utility can't, but not always. I've had Time Machine backups that DU couldn't fix; in some cases DW could, but in others, it couldn't.

IIANM, Disk Utility isn't going to be a sensitive test for errors in the backup sparsebundle. If it were that simple, then surely Apple needn't have waited until 10.6.3 to add the verification feature to Time Machine. (Though I will now go and run Disk Utility anyway just out of curiosity...)

There seem to be two different verifications. On every network backup, you should see a "QUICKCHECK ONLY; FILESYSTEM CLEAN" message. Usually, it only takes a few seconds.

Other times, you'll see that message twice; the second one takes much longer, roughly the time required to do +*Repair Disk,+* so it appears that's what it's doing. That one will also send a "Backup verification passed!" message (unless it finds a problem, of course). What triggers the second, longer one, is, naturally, a mystery too.

Pondini

Thanks for the advice I've put a 2tb USB drive on our home server mac mini partitioned 1tb for server and 2x500gb partitions for our 2 MacBooks. So hopefully that will stay reliable.

Ben

benh78 wrote:
Pondini

Thanks for the advice I've put a 2tb USB drive on our home server mac mini partitioned 1tb for server and 2x500gb partitions for our 2 MacBooks. So hopefully that will stay reliable.

Cool. Yes, that should be more reliable.

Pondini wrote:
I hate to have to tell you this, but Time Machine backups via an Airport Extreme to a USB disk are "iffy" and +*not supported by Apple.+*

I'm aware of the support article stating that it's not supported, but the fact attaching a disk to AEBS works for TM leaves bit of a bad feeling concerning how this is handled by Apple.

Should you happen to have an AirDisk mounted when you set up TimeMachine it will display the AirDisk as a valid backup target and start backing up to it without any warning whatsoever. No special instructions are needed for setup - only that the disk is mounted when setting up TM.

How it can be rationalized that a normal user that may not have ever read any of Apple support articles - much less the one stating that the configuration is unsupported - should be aware they did something wrong and unsupported?

In addition to the moral side of not supporting something that can be done that simply, at least in Finland there may be legal obligations as it falls well within something that "normal person" could conceivably be doing.

Brdgr wrote:
. . .
How it can be rationalized that a normal user that may not have ever read any of Apple support articles - much less the one stating that the configuration is unsupported - should be aware they did something wrong and unsupported?

You're not talking to Apple here. This is a user-to-user forum. The most anyone here can do is point out that it's not supported and offer alternatives.

In addition to the moral side of not supporting something that can be done that simply, at least in Finland there may be legal obligations as it falls well within something that "normal person" could conceivably be doing.

Then I guess you'd better either return your Airport or talk to an attorney about filing a lawsuit.

Pondini wrote:
You're not talking to Apple here. This is a user-to-user forum. The most anyone here can do is point out that it's not supported and offer alternatives.

I'm well aware of that.

The question was mostly rhetorical. I just raised the issue to question the attitude with which the issue is handled by Apple and apparently people here as well - the attitude that people that are backing up to AirPort disk are somehow stupid for doing that because it's clearly unsupported. All this without concerning at all that persons doing so may have just used the system as it appears to be intended to be used.

Then I guess you'd better either return your Airport or talk to an attorney about filing a lawsuit.

I do not understand that kind of confrontational attitude, just noted a fact concerning the situation.

And for what it's worth, I personally do not even have an AirPort disk connected to AEBS, much less having TM doing backups to one, so this does not currently affect me personally.

I find it somewhat amusing that even for this the solution is the allmighty lawsuit, which seems to be the catch-all solution for everything in the US and naturally you assume that the same applies everywhere.

I have the same problem with the "Time Machine completed a verification......must create a new backup for you" message. I am running a mac book on a wi fi with an Airport Extreme (1T). I payed the price to have a reliable system. I am having this message about every week. I did my last full backup on Dec 25th and had the same message yesterday, Dec 30.
I am also running an iMac on the same Airport Extreme and have had no problems with it's backups.

So....I don't think it has anything to do with hooking an external drive to the Airport.

I called Apple support yesterday and they seemed surprised that I was having this problem. We lost our phone connection so we never completed the trouble shooting.

Brdgr wrote:
. . .
The question was mostly rhetorical. I just raised the issue to question the attitude with which the issue is handled by Apple and apparently people here as well - the attitude that people that are backing up to AirPort disk are somehow stupid for doing that because it's clearly unsupported. All this without concerning at all that persons doing so may have just used the system as it appears to be intended to be used.

On the contrary, the link provided says that Apple doesn't make it clear. I'm just pointing out the facts (and the post you quoted started: "I hate to have to tell you this, but ...").

I find it somewhat amusing that even for this the solution is the allmighty lawsuit, which seems to be the catch-all solution for everything in the US and naturally you assume that the same applies everywhere.

You raised that, not me: *" at least in Finland there may be legal obligations"*

Pondini, thanks for the excellent guidance and documentation. For Time Machine to a shared drive on another Mac, is a separate partition for each source computer required?

Message was edited by: peterparker