Time machine backup fails with 'sparsebundle' error

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Time machine backup fails with 'sparsebundle' error

Time Machine couldn't complete the backup to "freenas".

The backup disk image "/Volumes/TimeMachine iMac-1/Vicki Passmore's iMac.Sparsebundle" could not be accessed (error(null).

The '-1' above is suspicious because the only mounted volume is TimeMachine iMac but I've no idea what to do about it

This error occurrs on our 2011 27" iMac running OS X 10.10.3 backing up (over Gb network) to a FreeNas volume and it used to be fine. A MacBook Pro is backing (wirelessly) up to its own volume on the same FreeNas and has done since the beginning without a problem.

Earlier I was able to resolve this problem by 'Remove Disk' & 'Stop Using This Disk" in the Time Machine preferences and then re-selecting the same disk. Gradually the frequency of 'sparsebundle' failures increased and now this fix no longer works.

I have turned Time Machine off and on. I have shut down both FreeNas and iMac and restarted

I have been scouring the web for answers to this problem and it seems that related problems occur a lot but there are no reports of problems with OS X 10.10.Yosemite and not with FreeNas and there seem to be no questions, let alone answers, since about mid 2014.

I have stopped short of trying Garth's terrifyingly complex command line repairs http://www.garth.org/archives/2011,08,27,169,fix-time-machine-sparsebundle-nas-b ased-backup-errors.html in the hope that a less scary solution exists.

Would be eternally grateful for any answers out there,

tim

iMac, OS X Yosemite (10.10.3), 8Gb Ram. FreeNas on HP Proliant 54L

Posted on May 20, 2015 4:41 AM

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Answer 1

rkaufmann87

Level 10

140,802 points

May 20, 2015 6:04 AM in response to MothyP

http://pondini.org/TM/A8.html

or

http://pondini.org/TM/C17.html

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Answer 2

Linc Davis

Level 10

209,547 points

May 20, 2015 7:19 AM in response to MothyP

A third-party NAS is unsuitable for use with Time Machine, especially if it's your only backup. I know this isn't what you want to hear. I know that Time Machine accepts the NAS as a backup destination. I know that the manufacturer says the device will work with Time Machine, and I also know that it usually seems to work. Except when you try to restore, and find that you can't.

Apple has published a specification for network devices that work with Time Machine. None of the third-party NAS vendors, as far as I know, meets that specification. They all use the incomplete, obsolete Netatalk implementation of Apple Filing Protocol.

If you want network backup, use as the destination either an Apple Time Capsule or an external storage device connected to another Mac or to an 802.11ac AirPort base station. Only the 802.11ac base stations support Time Machine, not any older model.

Otherwise, don't use Time Machine at all. There are other ways to back up, though none of them is anywhere near as efficient or as well integrated with OS X. I don't have a specific recommendation.

If you're determined to keep using the NAS with Time Machine, your only recourse for any problems that result is to the manufacturer (which will blame Apple, or you, or anyone but itself.)

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Answer 3

MothyP Author

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May 20, 2015 2:20 PM in response to Linc Davis

Many thanks for the reply Linc, although your response is more than a little troubling - the NAS is our only back-up. The weird thing is that it has worked fine on the iMac in the past. I have been able to go back to old versions of files (not a full restore I realise) and our MBP seems to behave.

I'll take a look at those links later.

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Answer 4

rkaufmann87

Level 10

140,802 points

May 20, 2015 3:20 PM in response to MothyP

MothyP wrote:

Many thanks for the reply Linc, although your response is more than a little troubling - the NAS is our only back-up. The weird thing is that it has worked fine on the iMac in the past. I have been able to go back to old versions of files (not a full restore I realise) and our MBP seems to behave.

I'll take a look at those links later.

The issue is OS X does not support NAS's, therefore TM was never intended to be a backup solution using a NAS. Apple clearly states to connect an EHD directly to a Mac, a NAS solution is never mentioned by Apple.

Your issue may be either your NAS provider has not updated their software to work on the version of OS X you use or you have not kept the NAS software up-to-date. In short, when using a NAS, you are pretty much on your own when attempting to use TM. My suggestion is for a smooth backup solution is to follow Apple's instructions.

While TM is a good solution, when it comes to backing up, a redundant backup solution is wise. What I mean is all HD's will fail and you don't want your only backup to fail. Many experienced users on these forums use multiple backups, for example one solution can be to use TM and a second solution could be to create a bootable clone (using Carbon Copy Cloner or SuperDuper) on a second EHD. That way if one EHD fails you have a backup.

Finally, it is also wise to test your backups on a regular basis just to ensure they are working as expected.

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