add'l ideas to cure slow Time Machine backup

Never occured to me to run AppleJack's repair functions individually to determine which one was helping. I just ran them all in "auto" mode. Should backups ever slow down again, I will do so and report back.

Prior to trying AppleJack, I used Disk Utility (repair disk and repair permissions) and OnyX (Automation function minus "Display of Folder" and "Spotlight Index"). Neither program helped even a little.

The only thing I can remember AppleJack reporting on was a large number of files needing permissions repair, but it always finds the same batch of files to repair every time (as does Disk Utility), so I figure Apple just set some wonky permissions.

Hoping to never have anything to report back on. ;-)

Craig

Craig Patton wrote:

. . .

The only thing I can remember AppleJack reporting on was a large number of files needing permissions repair, but it always finds the same batch of files to repair every time (as does Disk Utility), so I figure Apple just set some wonky permissions.

There are a bunch that can be ignored: http://support.apple.com/kb/TS1448

No doubt they both use the diskutil UNIX command, for both Verify Disk and Repair Disk Permissions, so there's no difference.

Shouldn't have anything do do with caches, since Time Machine excludes them automatically.

Pomdidni wrote:

....

"No doubt they both use the diskutil UNIX command, for both Verify Disk and Repair Disk Permissions, so there's no difference."

Just wondering...

Would running in "Single User Mode", as AppleJack does, allow the cleaning/repairing of files that other utlities cannot modify?

Craig Patton wrote:

. . .

Would running in "Single User Mode", as AppleJack does, allow the cleaning/repairing of files that other utlities cannot modify?

I don't think so, at least not OnyX.

The thing you have to be careful about is not to delete a cache for an app that's running. OnyX quits all apps, so it's not a problem.

I don't use single user mode much, or Applejack, so don't know if either (or both) does that.

After my last AppleJack run and posting here, back ups were fine for several weeks then jumped up to the 5-10 minutes range. This time I ran AppleJack's functions one at a time to try to determine which function was the cure. As the list below shows, only the "auto" run fixes the slow back ups. This is odd as "auto" should be the same as running all the functions individually in sequence. Apparently it is not.

I tested TM twice after each AppleJack run as experience has shown that the first back up after fixing the problem would be somewhat better, but the second backup would really fly.

The key appears to be "Event store UUIDs don't match for volume: Ext 500(boot volume) Node requires deep traversal:/ reason:must scan subdirs|new event db|". Just how running AppleJack in the auto mode triggers this while running each function individually does not is a mystery me.

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Back ups before AppleJack runs

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

Node requires deep traversal:/Users/nikko/Pictures/iPhoto Library/Database/apdb reason:contains changes|must scan subdirs|fsevent|missed reservation|

No pre-backup thinning needed: 1020.8 MB requested (including padding), 465.00 GB available

Copied 19221 files (139.9 MB) from volume Ext 500.

No pre-backup thinning needed: 919.9 MB requested (including padding), 464.85 GB available

Copied 13853 files (51.2 MB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 9 minutes 47 seconds

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After AppleJack disc repair...

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

No pre-backup thinning needed: 901.7 MB requested (including padding), 464.86 GB available

Copied 19156 files (12.7 MB) from volume Ext 500.

No pre-backup thinning needed: 858.6 MB requested (including padding), 464.84 GB available

Copied 13772 files (70 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 5 Min 53 seconds

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After AppleJack permissions repair...

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

No pre-backup thinning needed: 859.0 MB requested (including padding), 464.84 GB available

Copied 19241 files (454 KB) from volume Ext 500.

No pre-backup thinning needed: 858.5 MB requested (including padding), 464.83 GB available

Copied 13860 files (6 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 6 minutes 56 seconds

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After AppleJack cache clean (sys & 501)

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

Ownership is disabled on the backup destination volume. Enabling.

No pre-backup thinning needed: 859.2 MB requested (including padding), 464.83 GB available

Copied 19384 files (553 KB) from volume Ext 500.

No pre-backup thinning needed: 858.5 MB requested (including padding), 464.82 GB available

Copied 14015 files (115 KB) from volume Ext 500.

Starting post-backup thinning

Deleted backup /Volumes/Ext 2000/Backups.backupdb/MacDaddy's iMac/2012-08-10-115441: 464.83 GB now available

Post-back up thinning complete: 1 expired backups removed

Backup completed successfully.

ET: 8 minutes 18 seconds

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After AppleJack cache clean (sys & 502)

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

Ownership is disabled on the backup destination volume. Enabling.

No pre-backup thinning needed: 859.1 MB requested (including padding), 464.83 GB available

Copied 19384 files (474 KB) from volume Ext 500.

No pre-backup thinning needed: 858.6 MB requested (including padding), 464.82 GB available

Copied 14015 files (115 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 6 minutes 21 seconds

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After AppleJack cache clean (sys & 503)

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

Ownership is disabled on the backup destination volume. Enabling.

No pre-backup thinning needed: 859.1 MB requested (including padding), 464.82 GB available

Copied 19384 files (467 KB) from volume Ext 500.

No pre-backup thinning needed: 858.6 MB requested (including padding), 464.81 GB available

Copied 14015 files (8 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 6 minutes 25 seconds

-------------------------------------------------------------------------------- -------------------------------------------------

After AppleJack cache clean (sys & 504)

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

Ownership is disabled on the backup destination volume. Enabling.

No pre-backup thinning needed: 859.2 MB requested (including padding), 464.81 GB available

Copied 19384 files (552 KB) from volume Ext 500.

No pre-backup thinning needed: 858.6 MB requested (including padding), 464.80 GB available

Copied 14015 files (8 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 6 minutes 24 seconds

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After AppleJack preferences validation

No corrupt prefs found for 501, 502, 503 or 504

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

No pre-backup thinning needed: 859.3 MB requested (including padding), 464.80 GB available

Copied 19384 files (592 KB) from volume Ext 500.

No pre-backup thinning needed: 858.6 MB requested (including padding), 464.79 GB available

Copied 14015 files (8 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 6 minutes 22 seconds

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After applejack VM clean out

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

No pre-backup thinning needed: 859.3 MB requested (including padding), 464.79 GB available

Copied 19384 files (556 KB) from volume Ext 500.

No pre-backup thinning needed: 858.7 MB requested (including padding), 464.78 GB available

Copied 14015 files (12 KB) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 6 minutes 59 secnds

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First backup after "applejack auto restart"

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

Ownership is disabled on the backup destination volume. Enabling.

Event store UUIDs don't match for volume: Ext 500

Node requires deep traversal:/ reason:must scan subdirs|new event db|

No pre-backup thinning needed: 859.9 MB requested (including padding), 464.77 GB available

Copied 863 files (454 KB) from volume Ext 500.

No pre-backup thinning needed: 858.7 MB requested (including padding), 464.76 GB available

Copied 301 files (353 bytes) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 2 minutes 26 seconds

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Second backup after "applejack auto restart"

Starting standard backup

Backing up to: /Volumes/Ext 2000/Backups.backupdb

No pre-backup thinning needed: 858.7 MB requested (including padding), 464.76 GB available

Copied 301 files (30 KB) from volume Ext 500.

No pre-backup thinning needed: 858.7 MB requested (including padding), 464.76 GB available

Copied 301 files (427 bytes) from volume Ext 500.

Starting post-backup thinning

No post-back up thinning needed: no expired backups exist

Backup completed successfully.

ET: 0 minutes 6 seconds

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Craig Patton wrote:

. . .

The key appears to be "Event store UUIDs don't match for volume: Ext 500(boot volume) Node requires deep traversal:/ reason:must scan subdirs|new event db|".

That means that Time Machine can't use the File System Event Store, a hidden log of changes kept by OSX on each disk/partition. Instead, it must "scan" every directory (folder) on your system, and compare it to your backups, to figure out what's changed and needs to be backed-up. Since even a small installation of OSX contains several hundred thousand folders, that takes much more time. See the blue box in How Time Machine works its Magic for details.

Usually, that's caused by such things as an abnormal shutdown or disconnection, a failed or cancelled backup, etc. Sometimes just starting up from a different boot volume will do it, sometimes not. See the blue box in #A6 of Time Machine - Troubleshooting for details.

In this case, it may be that no individual operation caused too many changes, but the combination did.

Note that in the first log you posted, it was not the OSX volume that needed a scan, but your iPhoto library, indicating that the iPhoto app was open during the previous backup in a way that prevented Time Machine from backing-up its changes.

By the way, if you're running these things regularly, for no particular reason, you may be causing more harm than good. Other than the "VM restart" which I'm not familiar with since I don't do Windoze, none of those processes are recommended unless you're having a problem.

Regular cache cleaning in particular will make your Mac run more slowly, not faster -- the whole purpose of a cache is to speed things up by not having to retrieve the same information again. On occasion, they do get damaged, and need to be deleted, but only if you're having a problem. If, for example, you find your browser very sluggish, but other things are running fine, clear your browser cache via the browser.

Thanks for the info. I don't run AppleJack as routine maintenance. I only use it when TM back ups get slow. I dislike the cache cleaning function as I realize it slows the system down, but "Applejack Auto" is the only way I know of to speed up my sluggish TM back ups.

The "blue boxes" explain many of the triggers for the deep traversal, but fall short of recommending a way to safely cause one. Is there a safe way to trigger that deep traversal in TM without resorting to AppleJack?

Better yet, would be a way to prevent the sluggish back ups. The key to prevention probably has something to do with those 20,000 files that come to only 500KB, but I have no idea what causes that.

As an aside, I might mention that I have for some time now been running from a portable FW800 external drive (Ext 500) as the internal drive in my iMac failed and the prices are still too high on replacements. "Timing (in Thailand) is everything".

Thanks again for the help.

Craig Patton wrote:

. . .

The "blue boxes" explain many of the triggers for the deep traversal, but fall short of recommending a way to safely cause one. Is there a safe way to trigger that deep traversal in TM without resorting to AppleJack?

Usually, folks don't want them; they want to avoid them. 😉

Starting from another source (a clone or your Install disc) and running Repair Disk will usually do it.

Better yet, would be a way to prevent the sluggish back ups. The key to prevention probably has something to do with those 20,000 files that come to only 500KB, but I have no idea what causes that.

As posted earlier, we've seen a small number of folks on 10.6.8 with slow backups and very large numbers of files reported. After trying all the other fixes, it appeared to be a problem with their installations of OSX.

Some of them reported fixing it by installing the 10.6.8 "combo" update, per Installing the ''combo'' update and/or Reinstalling OSX. If that didn't help, installing a fresh version of OSX (that won't disturb anything else), per the same article, often did.

A very few reported that didn't help; but reinstalling OSX again, then only going back to 10.6.7, instead of 10.6.8, did. (If you do that, be aware of the 3rd item in #D5 of Time Machine - Troubleshooting.)