Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Why is my Time Machine backup so slow?

In short: A backup of 2 Mbytes takes more than half an hour


Long version

I used Time Machine with my old iMac and of course I am using it with my new iMac (SSD + 2 TB). The Backup destination is an external FireWire drive with 2 TB, the same I used with the old iMac.


The first backup took some time (more than 700 GB), but this is normal, I assume. Now I have problems with the "small" delta backups. Just one example from the console output:


27.06.11 17:56:20 com.apple.backupd[8775] Starting standard backup

27.06.11 17:56:20 com.apple.backupd[8775] Backing up to: /Volumes/Archiv 1/Backups.backupdb

27.06.11 17:57:56 com.apple.backupd[8775] No pre-backup thinning needed: 855.7 MB requested (including padding), 883.02 GB available

27.06.11 18:06:31 com.apple.backupd[8775] Copied 226532 files (1.8 MB) from volume Speedy HD.

27.06.11 18:06:50 com.apple.backupd[8775] Copied 226781 files (1.8 MB) from volume Speedy Medien.

27.06.11 18:09:48 com.apple.backupd[8775] No pre-backup thinning needed: 871.3 MB requested (including padding), 882.92 GB available

27.06.11 18:17:59 com.apple.backupd[8775] Copied 178604 files (236 KB) from volume Speedy HD.

27.06.11 18:18:19 com.apple.backupd[8775] Copied 178853 files (236 KB) from volume Speedy Medien.

27.06.11 18:24:55 com.apple.backupd[8775] Starting post-backup thinning

27.06.11 18:33:17 com.apple.backupd[8775] Deleted backup /Volumes/Archiv 1/Backups.backupdb/Speedy/2011-06-26-171728: 883.00 GB now available

27.06.11 18:33:17 com.apple.backupd[8775] Post-back up thinning complete: 1 expired backups removed

27.06.11 18:33:18 com.apple.backupd[8775] Backup completed successfully.


As you can see from the log there is no single error message or warning but the backup of about 2 MBytes took 37 Minutes !! And this happens every hour. Most time of the day my iMac is backing up!! If I add some content to my iMac, (e.g. the backup of a new TV show with 3 GBytes) the backup is as fast as expected (at least the copy phase of Time Machine). Nevertheless every backup has a long preparation and a long cleanup phase. During these ridiculous long phases the activity of the external FireWire drive is very high, I hear the head of the drive positioning all the time.


I checked all discs with disk utility, repaired all rights, rebooted the iMac and switched the external drive off and on.


The backup source consists of the SSD and the HDD of my iMac. For the HDD I disable access rights management to share an iPhoto library easily between multiple users in our family.

iMac, Mac OS X (10.6.8), iMac mid 2011

Posted on Jun 27, 2011 10:40 AM

Reply
Question marked as Best reply

Posted on Jun 27, 2011 11:30 AM

In case you haven't found it, Pondini's website is a super resource on Time Machine.


Try this page - http://web.me.com/pondini/Time_Machine/D2.html

107 replies

Jul 1, 2011 12:53 PM in response to Pondini

Pondini wrote:


That's an "expired" backup. Time Machine doesn't keep all backups until space runs out; it "thins" them according to the schedule on the TM Prefs panel. It keeps all for 24 hours, then one per day for a month, then one per week as long as there's room.


The one it deleted was over 24 hours old: 2011-06-29-074504


:facepalm: Of course. I keep hoping stupidity is curable, then I come out with some really dumb thinking like my prior post. Thanks, James!


John

Jul 1, 2011 1:04 PM in response to NewBartleby

NewBartleby wrote:

. . .

(stupid newbie question: how do you copy a portion of the post you are replying to? I mean, to cite... nothing I tried worked... this is surely not my day!)

Two ways; copy the whole thing (by clicking the quote icon in the toolbar), then delete what you don't want.


Select and copy the section you want, then select the copied text and click the quote icon.

Jul 1, 2011 1:25 PM in response to TomRadfahrer

I still enjoy a fast backup. Some of my backups last night took 8 minutes. Way faster than before the deep traversal, but still too long. The reason for such a long backup was always the "post backup thinning", which took 7 minutes. Now, 24 hours are over and any backup which needs to be erased had been created after the deep traversal operation. As a result total backup time is between 50 seconds and 90 seconds.


Hopefully Apple will fix this error soon. I wish you luck.

Jul 1, 2011 11:28 PM in response to NewBartleby

Erasing the external disk (the backup destination) has no positive effect. I tried it two times and it does not work. It is not the external disk, which is corrupt! It is the internal SSD (the backup source)!


Time Machine has some sort of cached information, which helps TM to replicate complete tree of unchanged folders by a single multi-link. If this cache is corrupt, TM generates for every file and folder in such a tree a single hard link per file/folder. These are the thousands of files, which are seemed to be copied during a long backup.

Jul 2, 2011 3:01 AM in response to TomRadfahrer

TomRadfahrer wrote:


Erasing the external disk (the backup destination) has no positive effect. I tried it two times and it does not work. It is not the external disk, which is corrupt! It is the internal SSD (the backup source)!




Well I don't know what else to do... I repaired the SSD twice from a DVD boot.


I'll try a re-index of Spotlight (I've seen that this, oddly, solved other TM problems) on Monday. If this fails...


Should I report this to Apple? How?


Thanks!

Jul 2, 2011 8:38 AM in response to NewBartleby

I have reported my situation to Apple. Here in the U.S., it can be done by calling a toll free number, but I prefer the option on Apple's support website, where I identify my previously registered product, describe the problem in text, and have them call me on the phone number of my choice.


That method is quicker and gets more rapidly to the people who have the appropriate skills.


May be different on Apple Spain's website of course.


The Apple rep was very knowledgeable and had me run software called "Capture Data" which collected log information for the technical people, which I emailed back. May take several days to hear back, but I'm in no real hurry. I'd prefer they have time to look at it and get a considered diagnosis.


I would definitely report it to Apple.

Jul 2, 2011 8:59 AM in response to John Kitchen

John Kitchen wrote:

. . .

The Apple rep was very knowledgeable and had me run software called "Capture Data"

You were fortunate to get to that one -- some are, shall we say, less expert. 😉



I would definitely report it to Apple.

Yes. And by all means, report back. If there's a fix, please give us the details, so others may benefit.

Jul 2, 2011 9:20 AM in response to Pondini

Pondini wrote:


John Kitchen wrote:

. . .

The Apple rep was very knowledgeable and had me run software called "Capture Data"

You were fortunate to get to that one -- some are, shall we say, less expert. 😉



I would definitely report it to Apple.

Yes. And by all means, report back. If there's a fix, please give us the details, so others may benefit.


I think the reason I got to this guy was in part because I explained what had been happening, and I explained the steps I had taken to diagnose and attempt repair and they exactly matched what the first level support person would have me do.


And guess how I learned what to do? In part from this community! So thanks!!


The next level support person confirmed that the actions I had taken were correct, such as


Repair on source and target partitions

Start a whole new Time Machine backup to an erased partition (not cleaned out via Finder)

Reviewing the system.log with the widget or Console etc


He said that I had done everything that he would normally walk me through, so had me run Capture Data and send the results to him. He said he might come back and ask me to run it again while Time Machine was "Finishing backup..." or "Cleaning up...", so I offered to do this anyway, and he accepted that offer. I have since sent both these Capture Data sets.


This person suggested that there may be an association of my TM issues with the 10.6.8 upgrade, and told me that the engineering people are very interested in identifying things that get broken in new releases, so my data will get quick attention.


And I know that things shouldn't get broken when a new release comes out, but this is complex stuff, and with all the testing resources that money can buy, some bugs will always slip through to be caught by us masses in the real world. Several decades in this industry repeatedly taught me that!


I will certainly let you know what the outcome is when it happens. Probably some time next week.


Until then, have fun.

Jul 4, 2011 8:28 AM in response to John Kitchen

Apparently the problem went away.


What I did: repaired disk/permissions from SSD (from a DVD boot), repaired HDD disk, erased TM external harddisk, repaired external harddisk (just in case), boot from SSD.


First backup (full) took less than three hours (as expected), first and second incremental took about five minutes. Still should be a bit faster, but these times are totally acceptable (before, it took about one hour for each incremental).


The only suspicious thing was that the disk utility found some wrong permissions on the SSD. Everything else was OK.


So far I am happy, I will report again if the incremental backup times start growing again. Hopefully not.


Thanks to you all! Still very interested in what Apple has to say about this. I found many others with similar problems in other forums.


Regards from Barcelona.

Jul 4, 2011 8:34 AM in response to NewBartleby

NewBartleby wrote:

. . .

What I did: repaired disk/permissions from SSD (from a DVD boot),

You need to do that again, but using Disk Utility on your Mac, not while booted from anohther source. This is because it uses information stored on your Mac about your installed apps. See About Disk Utility's Repair Disk Permissions feature for details.



first and second incremental took about five minutes. Still should be a bit faster,

Look at the size of the backups. If they seem too large, see #D4 in Time Machine - Troubleshooting for some common culprits and ways to determine exactly what's getting backed-up.


If the size seems reasonable, but they still seem too slow, see #D2 there, especially the green box.

Jul 4, 2011 9:25 AM in response to Pondini

Pondini wrote:

What I did: repaired disk/permissions from SSD (from a DVD boot),

You need to do that again, but using Disk Utility on your Mac, not while booted from anohther source. This is because it uses information stored on your Mac about your installed apps. See About Disk Utility's Repair Disk Permissions feature for details.


Ok, I did it again. Told me:

ACL found but not expected on "private/var/db/launchd.db/com.apple.launchd".

Repaired "private/var/db/launchd.db/com.apple.launchd".


Should I be concerned?



Pondini wrote:

Look at the size of the backups. If they seem too large, see #D4 in Time Machine - Troubleshooting for some common culprits and ways to determine exactly what's getting backed-up.


If the size seems reasonable, but they still seem too slow, see #D2 there, especially the green box.


They seem perfectly normal. I just think that they could be A BIT faster than my previous iMac considering this has an SSD, but I am being stupid since the main difference for the incremental backup was a lot of photos and movies I placed in the hard disk. :-)


Hey, Pondini, great work! Thank so much for the troubleshooting guide you compiled and all your help.


Regards

Why is my Time Machine backup so slow?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.