2011 iMac and Slow Time Machine Incrementals

[basher]

Anyone with a 2011 iMac configured with SDD + HDD expriencing slow incremental backups via Time Machine.

I tried resetting PRAM, repartitioning my firewire backup drive. And rebooted several times. Also, my system updates are current.

The problem occurs with three different drives and also via USB or firewire.

 

[Detrius]

There are any number of possibilities, and as a technician, my first thought is bad hard drive. Obviously, there are software possibilities, too but when people complain, it's more often a bad hard drive.

 

[basher]

Yeah, I was thinking it was a bad firewire drive. But when I got the same poor results from additional drives under time machine I kind of started to think it has to be something other than hardware. Also file copies are running really fast.

Any other things to check are greatly appreciated.

 

[Wiggo]

Antivirus software? I've read many complaints like this solved by turning off antivirus software.

 

[DJHack]

Anyone with a 2011 iMac configured with SDD + HDD expriencing slow incremental backups via Time Machine.

I tried resetting PRAM, repartitioning my firewire backup drive. And rebooted several times. Also, my system updates are current.

The problem occurs with three different drives and also via USB or firewire.

I have to admit that since I've rigged up my new iMac to time capsule it seems to always be backing up! I'm haven't really watched how long but, as opposed to my MBP, the iMac sees to always be running backup which would suggest it's taking longer.

It s the same time capsule as MBP backed up too and the MBP wasn't slow?

 

[Sjhonny]

What's slow? like 200 KiB/s ... 1 MiB/s ... 10 MiB/s ?
could be large amounts of very small files

 

[basher]

Not running any AV software. I did read something about spotlight sometimes causing trouble.

The problem is really strange. The initial backup would run fast. It would take about 2.5 hours to backup 200GB via firewire. Then after that the incrementals would just crawl to about 8k every 5 minutes.

Right now I'm seeing how things go now that I told spotlight to not reference the Time Machine drive. So far the initial backup is taking about 34 seconds for a GB worth of data. And that's hooked up to USB.

 

[basher]

PROBLEM SOLVED - 2011 iMac and Slow Time Machine Incrementals

Problem solved.

After trying repair disk on all drives only to find out there were no issues I decided to take a look at permissions across my drives.

As it turns out on the HDD in my SDD+HDD set up my user account had the wrong group assigned to them. Somehow all files in my user account on the HDD were set to a group of 'admin'.

To fix the issue I sent in to terminal and issued a chgrp command to set them to 'staff'. Once the chgrp was complete I reformatted my time machine drive and started a fresh backup.

The initial backup of 205GB worth of data to a firewire drive took 2 hours and one minute. After that hourly backups started and were taking under 10 minutes to complete. I guess even though there were no files changed during the hourly backups, because I was sleeping, Time Machine still needs time to coordinate if there are changes in files.

During my troubleshooting I did learn how valuable and easy it is to use the Console utility. Filtering on 'backupd' really gave me a good feel for how long things were taking.

Thanks to those that replied to this thread!

Basher

 

[Detrius]

Problem solved.

... I reformatted my time machine drive and started a fresh backup.

I'd like to point out that this is what fixed your problem. It wasn't permissions causing the problem. Permissions will absolutely never ever slow things down. They will cause things to fail, but it is conceptually impossible for permissions to slow things down.

 

[basher]

I'd like to point out that this is what fixed your problem. It wasn't permissions causing the problem. Permissions will absolutely never ever slow things down. They will cause things to fail, but it is conceptually impossible for permissions to slow things down.

So I guess the other 5 times I formatted(including deleting partitions and setting GUID table) the drive before changing permission were faulty.

 

[Detrius]

So I guess the other 5 times I formatted(including deleting partitions and setting GUID table) the drive before changing permission were faulty.

I'm inclined to think it's coincidence and something else must have changed. e.g. bad sectors on the drive may have gotten mapped out. I have no remotely plausible explanation for why permissions would make a dramatic speed difference, and I challenge you to find someone else who does have an explanation.

(Permissions are like the on-off wall switch for your light. It's either on or it's off. The switch doesn't change the speed of light, and it doesn't change the color.)