Why is time machine backup slow?

Question

Why is time machine backup slow?

Hi there

I am trying to backup my MacBook Air to my Time Capsule and it is going very slowly. In total there is about 400GB data to back up. I started a fresh backup to the empty Time Capsule (2TB capacity) on Friday last and by Monday morning when I need to use my MacBook Air elsewhere it still had 55GB to go. I started the backup agin this morning (6 hours ago) and it has so far managed 778MB of the 55GB. So a quick calculation means that will take approx. another 17 days. I appreciate that I am doing this over WiFi which is slower than a wired connection but the Air has no network socket, but this is frankly ridiculous. Any ideas welcomed!!

MacBook Air, OS X El Capitan (10.11.6), MacBook Air Mid 2012

Posted on Sep 27, 2016 5:51 AM

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Answer 1

JimmyCMPIT

Level 7

29,306 points

Sep 27, 2016 6:07 AM in response to Mike Watkinson

So first off that initial backup is writing an index so its not just data here, data there.

secondly IMHO over wi-fi, terrible idea for a primary backup. a network backup should be a secondary, third choice for backup because you have introduced several points of failure and inherent latency issues and could cause problem with your backup. What your asking the software to do under the circumstances is why you are seeing these time estimates.

Use Time Machine to back up or restore your Mac - Apple Support

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Answer 2

Sep 27, 2016 6:31 AM in response to JimmyCMPIT

Ok - thanks for your reply. I understand that backing up using a wireless connection to the Time Capsule is going to be slower than a cabled connection, but to be fair I don't see 'don't use WiFi' in Apple's guidelines (which doesn't mean that it isn't there of course!) In terms of speed this is going way slower than if I backed up the whole lot to a cloud service via the exact same router, which is one reason for my question. With I have a MacBook Air I can't connect to the Time Capsule using an ethernet cable or USB, so WiFi is the option I have. Any further thoughts welcomed!

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Answer 3

Lexiepex

Level 6

14,108 points

Sep 27, 2016 7:44 AM in response to Mike Watkinson

Jimmy is right, 400GB over WiFi will take days at least. Then, additional backups will be unnoticed. It is not possible to connect a cable between your mac and the TimeCapsule to speed up things: it will not connect the disk.

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Answer 4

Oct 1, 2016 2:24 AM in response to Lexiepex

Hey guys - thanks for the responses - certainly helped me prepare for the long wait! It went quicker then the original production eventually taking about 8 hours - not too bad! But - now it should be making incremental backups yes? So TM reports 115.MB to back up, but has been stuck at 'Calculating time remaining' for over two hours. Any thoughts on why this is happening?

Thanks in advance.

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Answer 5

Lexiepex

Level 6

14,108 points

Oct 2, 2016 2:41 AM in response to Mike Watkinson

That slowness may happen in the beginning (TM is using only free cpu sycles, should go unnoticed), but it should not be so slow as you say; 5 minutes perhaps, but not hours to prepare.

Are you sure there is no issue with the TC?

When you look at the TC with Finder you should see the disk, only one folder called Data, nothing else. in the Data folder there is the Backup folder with all inremental folders in it.

In SystemPreferences->Spotlight: the TC should be in the Privacy tab, if not add it there.

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