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time machine very slow with mountain lion

Time Machine backups seem very slow with Mountain Lion.

iMac, Mac OS X (10.7.4), 2.66 GHz Intel Core i5, 8 GB

Posted on Jul 27, 2012 7:36 AM

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650 replies

Jul 29, 2012 2:45 AM in response to 1tombhome

Just upgraded to ML yesterday, started the backup right after this upgrade and the estimated time increased to 35.654 days after 30 minutes of backup. after 1 hour it decreased to 20 days and after backing up 10GB (12 hours later) of the total of 41GB it stopped. Again started time machine and again about 30.000 days to backup all the information (31GB). After about 4 hours another 10GB is backed up and......yes it stopped again. Now I started the backup again and another 40.000 days is needed to backup😝. It seems there is a problem after 10GB op backup, it needs to check all former backed up information and then it start to backup again but a lot slower then with Lion. Normally with Lion it takes about 10 hours to create the first compleet backup, the incrementals took about a few minutes (max 1 hour when there are lots of changes).


Hopefully Apple will fix this problem.

Jul 29, 2012 4:33 AM in response to Contradel

I'm suffering from very slow backups under Mountain Lion. After installation it took an overnight session to backup what had changed since the upgrade, now it takes forever to backup even just a few megabytes. Also I am getting the 'cannot find disk' errors, never had them before Mountain Lion.


I'm running Mountain Lion on a mid 2010 MacBook Pro and backing up to a 2TB Time Capsule purchased almost exactly 12 months ago.


If anyone has any suggestions to fix this I'd be most grateful.


Regards,


Jamie

Jul 29, 2012 6:37 AM in response to AnKBe

Before you fully reinstall, delete the sparse-bundle from your backup device and let Mtn Lion create a brand new backup.


Whoa, there! That's some spectacularly bad advice!


For many people, their Time Machine backup is their one-and-only backup. And a couple common causes of the kinds of problems being described on this topic are a badly corrupt hard drive and a physically failing hard drive. How is someone going to feel if they delete their one-and-only backup, only to find that their original data is damaged beyond repair?


Certainly, deleting a Time Machine backup may sometimes be required, if the backup itself has become irreparably damaged. However, that should NEVER be done without having at least one additional, secondary backup, made with some other software (such as Carbon Copy Cloner).


I would advise anyone having difficulties with Time Machine to visit:


http://www.pondinin.org


Pondini is an extremely knowledgeable member of these forums, and he knows just about everything there is to know about Time Machine.

Jul 29, 2012 6:53 AM in response to AnKBe

Already tried that (formatting Time Machine device, which in my case is a SD card). It didn't work. I have all my documents in Dropbox anyway. Rest is just time.


So I tried a full reinstall via the restore partition. Downloading the rest of the OS took about 2 hours, little did I know, that apparently reinstalling the OS doesn't format the drive. All your documents and apps persists, only the system core files are being reinstalled. Unfortunately the Time Machine backup problem also still persists. I'm not about to try this one more time, with a force format of my main drive, I already wasted way to much time on this.


Hate to say it, but at this point, hearing how many got the same problem. I'm just going to wait for Apple to push a fix or instructions. Meanwhile I'm going to use "SuperDuper" which seems to backup all of the drive, faster than Time Machine backs up 500 MB. 😮

Jul 29, 2012 7:46 AM in response to thomas_r.

Sorry but I disagree with you. I periodically purge the sparsebundle to create a fresh backup. And in this case, it solved my time machine issue with Mountain Lion. And for the record, I'm on a new MBP purchased a month ago, and the backup was new when I got this machine.


Obviously there is risk to deleting/recreating the time machine backup. But in this case, that risk isn't any worse than the situation that is occuring with the Mtn Lion backups

Jul 29, 2012 8:03 AM in response to AnKBe

Obviously there is risk to deleting/recreating the time machine backup. But in this case, that risk isn't any worse than the situation that is occuring with the Mtn Lion backups


Yes, there is risk, which you didn't mention, and which is easily avoided by having secondary backups in place. And that risk is FAR worse than just slow backups... if someone is experiencing slow backups because their internal hard drive is failing, and they delete their one-and-only backup, they may very well never see some or even all of the data on the internal hard drive again.

Jul 29, 2012 8:09 AM in response to thomas_r.

Also what you didn't mention is if the drive is failing, it is likely that the backup is no good anyways. And in my case, deleting the 1 month old sparsebundle created under Lion solved my slow backup issue.


The original poster obviously knows what he's doing since he's already taken it upon himself to rework his backups, including reformatting his drive. I think he is more than capable of understanding the concept of deleting his sparsebundle.

Jul 29, 2012 8:43 AM in response to AnKBe

Also what you didn't mention is if the drive is failing, it is likely that the backup is no good anyways.


That is not necessarily the case, especially with an incremental backup system like Time Machine that allows you to go "back in time." If files become corrupt due to a failing hard drive, Time Machine may be able to let you restore to an earlier point, before the corruption.


And in my case, deleting the 1 month old sparsebundle created under Lion solved my slow backup issue.


That means that your backup was probably corrupt, and that solution was appropriate, as long as proper precautions were taken. That will not be the case for everyone, but it's a reasonable thing to try... again, as long as proper precautions are taken.


The original poster obviously knows what he's doing since he's already taken it upon himself to rework his backups, including reformatting his drive. I think he is more than capable of understanding the concept of deleting his sparsebundle.


You forget that you are addressing an entire community, and not just in the present but in the future as well. Countless people will come across your advice, even years in the future. If there is an aspect to that advice that is dangerous, it needs to be corrected, lest it lead someone down the wrong path. Deleting your Time Machine backup if you don't have any other backups is highly dangerous, for the reasons I've already mentioned.

Jul 29, 2012 10:36 AM in response to 1tombhome

My local Time Machine backups still function, a bit slower than before. But over the network backups, to a drive on another Mac are abysmal. And yes it worked *just fine* before I installed ML thank you. I ran Disk Utility on both Macs and it fixed up a few link issues, but the problem still remains: it's ridiculously slow and then just poops out for some reason; stopping after maybe 80-100 MBs, and that paltry amount of space takes hours over gigabit Ethernet.


As for Spotlight indexing being a cause, I did the trick of adding a drive to Privacy and removing it. The re-index took a couple hours (256 GB drive), but it has made no impact on Time Machine's performance that I can see.


Looking in the console while TM is running (after the re-index), there appears to be permission problems with Spotlight's mdworker and some of the files it's trying to copy. Running Repair Permissions from Disk Utility hasn't made a difference for that either.


I do have a fair amount of exclusions, I'm tempted to try removing them all and see if that helps.


Yeah, TM appears to be quite broken with this initial release of ML. 😟

Jul 29, 2012 11:38 AM in response to Pete Helme

That is exactly my experience. TM runs normally when backing up to a USB drive, but it is orders of magnitude slower (no exaggeration there) to a network drive over GigE. It used to work great with Lion.


One thing I happened to notice--in Apple's description of ML Server (additional $19.99), it says:


"OS X Server can act as a designated Time Machine backup location for all the Mac computers on your network. Centralizing your backup storage helps protect valuable data and free up disk space on individual drives. And it eliminates the need for separate backup drives altogether." (see http://www.apple.com/osx/server/features/ ).


So do you suppose network backups will work will work correctly in that case? I'm almost tempted to install ML Server on the Mini that is hosting the shared backup drive. I'm not paranoid enough to suggest that Apple intentionally broke something to get people to spend another $20, but it is interesting...

time machine very slow with mountain lion

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