Slow backups w/Time Machine and an External HD

Tech Support
6

Time Machine is designed to work with a drive that is connected continuously (or frequently, like daily). Connecting just once a week may be part of the issue. It’s not just copying files — there’s a lot more to it, and I’ve seen the “preparing” step take hours. In the past, this seemed to be more likely to happen when the Time Machine disk was getting full. (This is my experience only, and it hasn’t happened in years.)

That said, I’ve also seen Time Machine get stuck on “preparing” because the backup became corrupted. In that case, the only solution is to wipe out that backup and begin again. Not a great solution. I’ve experienced this twice, but it hasn’t happened to me in 4-5 years. I hope that means Time Machine has become more stable!

If you’re not going to keep a TimeMachine drive connected continuously/frequently, I recommend looking at a different backup solution. Continuous backup is much safer than periodic, but a periodic backup in addition to continuous is a good idea. I use Backblaze (and TimeMachine) for continuous and Carbon Copy Cloner for periodic backups.

Storing everything in the cloud is not a backup. Sync is not backup. If you mistakenly delete (or software corrupts) a file, sync will repeat that error everywhere, and there’s no (easy) way to recover a previously-synced version.

I agree on the case-sensitive being a red flag, but Apple does say it’s OK:

2 Likes
7

This is a very helpful reply, thank you!

8

Your replies have convinced me that we should have something networked and daily. (Honestly, I thought NAS was a brand until now). There’s so much to learn and I don’t have time for this! Any pointers to help me understand where to begin with meeting my needs (which I think are fairly small – one home, two MBPs w/2TBs of storage each)?

9

I think Backblaze and Carbon Copy Cloner (CCC) would be much less demanding of your time.

The NAS is something you “administer,” not very appliance-like in my experience. (I have a Synology DS918+ $550+4x$120 for drives =~$1k). Admittedly, some of mine could be self-inflicted by learning it’s capable of something, then working to implement that. If I had it to do over, I would probably get a Mac Mini and a couple of external drives. Other people with differing opinions will probably chime in and tell you how super easy it is, and that there are cheaper options, as is their right.

For Backblaze, I’m backing up my M1 MBP and my iMac Pro, I also pay extra for the 1-year data retention, total per year is $168. While I’m a student and make a pittance, I consider $168 to be worth about 2 hours of my time.

CCC is $40.

External 4T drives are about $110.

3 Likes
10

I think you’re right! Looking into Backblaze and CCC rn, thanks all!

2 Likes
11

Time Machine seems to be in need of some serious love and attention by Apple. Over the past couple of years it has become horribly slow and unreliable when used over a network - and for anyone with a laptop that’s how one would want to use it! I’ve been backing up MacBooks to networked drives for years now - first using a Synology NAS, and then to external drives on a networked Mac Mini, and it used to be an easy, reliable, set-and-forget, option. However, since Catalina and Big Sur it has become a recurring nightmare, with backups taking hours, even days, and then anyway failing before completion. My M1 MBA has not managed successfully tp complete a TM backup in several weeks! One problem has been that the system seems no longer to be able to deal with a laptop going to sleep, which is a rather fundamental failing!

Of course, the drives to be backed up have been growing, but I don’t believe that can possibly account for the increasing times taken to complete TM backups. Rather, I suspect that this problem has been generated in code changes required by the adoption of the APFS file system. But whatever the cause, Apple need to take a serious look at TM, which as currently implemented seems no longer to be a viable backup system for laptop computers.

2 Likes
12

At my previous company we used Time Machine over the network but found backups would become corrupt after 4 to 6 months. Eventually we stopped using it around 2016 - 2017.

After I installed Big Sur I did try Time Machine on a locally attached APFS formatted drive. Backups were fast and everything seemed OK for the first couple of weeks. I did a successful test restore after the first complete backup, but when I tried again a couple of weeks later the backups could not be read. I ended up formatting the drive and replacing Time Machine with ChronoSync.

2 Likes
13

This has been my experience with TM, even with directly-connected drives.
I just don’t trust it anymore. I still like the whole Time Machine paradigm, but as @baldbeardie said, TM needs some attention (as does Apple Mail).

2 Likes
14

Issues with Time Machine slowness have gone away since I used the Time Machine Editor app to increase my backup interval from the default one hour to three hours between backup attempts (YMMV). To get through your first Time Machine backup, turn off automatic backups and start one manually when you can leave it running all night undisturbed.

1 Like
15
1 Like
16

I have been running Time Machine over wifi to back up my MacBook Pro to a shared drive attached to an always on Mac. I am trying to get the benefit of automatic backups without having to plug in an external drive since I use my laptop all over the house (I also use Backblaze so I am not concerned about full data loss), but it’s absolutely brutal. Backups take forever, run past the advertised amount of data to backup, always cleaning up or verifying, and makes the fans scream. It’s a joke.

1 Like
17

During the time we were using TM over the network, I used a Mac mini dedicated to backing up only one senior executive and, as I recall, 4 Drobo 5Ns. Each Drobo had 4 or fewer clients and all devices were on a wired 1gb connection.

Sometimes the Macs would just stop backing up requiring me to remove and re-setup the connection to the destination device. When the volume assigned to the Mac became full TM would not automatically remove the older backups. This occurred on both the Mac mini server and the Drobos. When this happened I would create a new backup volume for the client, then delete the old backup volume after the initial backup on the new volume had completed. But the final straw was the TM backups would eventually become unreadable.

At this point our managers were told we would no longer be backing up their Macs and they should keep both their company data and any personal files in their private directories on a file server. (The majority of our employees used only email and web based applications and didn’t require backups). Eventually we moved to a cloud based backup system.

Have you looked at ChronoSync? This app combined with their ChronoSync Agent, which would run on your always on Mac, was the immediate solution I used to replace TM for our senior executive. It was extremely reliable.

2 Likes
18

Thanks for the suggestion @WayneG. What I most like about Time Machine is the ability to browse history by date to access previous versions of files and deleted files. It looks like ChronoSync’s solution to this is their Archive feature. Is that right? Do you experience with how using ChronoSync for this would differ from Time Machine? Thanks!

19

Correct. To restore a file you can use the Archive panel in Chronosync or browse/search the archive folder the same as any other. You can customize what is archived, how many versions to keep, and for how long.

CS Archive
CS Archive862×354 29.2 KB

I purchased my personal copy of CS in March 2007 and later purchased multiple copies for my company. It is rock solid and you get free upgrades for life.

Both Chronosync and Chronosync agent are free to use for 15 days.

1 Like
20

Hi Beck.

I have been talking to Apple support over the problem of slow Time Machine backups, which first appeared with Catalina, and has continued into Big Sur.

I was trying to backup a new M1 MacBook Air with about 350GB of data on the SSD. The backup disk was an external drive on a Mac Mini.

Like you, I thought that the backup had frozen, but if I let it continue, it did complete - although it took a long time: just under 30 hours! Subsequent backups were taking maye 7 or 8 hours - and of course, on a laptop this means that backups simply were not completing.

The first thing that Apple told me is is that I should make sure the backup disk is formatted in APFS, Having done this (and I had some initial trouble getting Time Machine to recognise the disk, but resolved that eventually by rebooting the laptop!) the time for the first backup dropped significantly - to about 11 hours, and subsequent backups now take about 2-3 hours. Using a wired connection to the Mac Mini did reduce the backup times, but not by very much. By contrast, using a directly connected drive the first backup takes about 3 hours, and subsequent backups a few minutes.

I am still not happy with backup times, but using APFS for the backup drive are certainly significantly improves things compared to using traditional MacOS formatting. So far as I am concerned this is still an open and on-going support situation.

2 Likes
21

I recommend you do a test restore every week or two for a while. My APFS TM backup was fine the first time I did a test restore. It was unreadable a couple of weeks later.

1 Like
22

After a little calm reflection, I have come to some conclusions about Time Machine. They may be wrong, but they may be useful starting points. I just wish there was some way of getting to talk to anyone in Apple about some of these things.

Conclusion 1: Time Machine is slower and less since the switch to SMB for talking to networked drives.

This is rather more of a hypothesis than a conclusion. However, it kind of fits in with the time that I started seeing problems, both with speed and with backups failures.

Conclusion 2: Time Machine problems have been amplified by the use of larger drives.

This is kind of obvious, really. My original MacBook had a 256MB SSD. My next two had 512MB SSDs, and my latest one has the full 1TB. More data to backup, so the backup takes longer to complete, so a bigger window for network problems. And no, I do not wish to return to tiny SSDs!

Conclusion 3: Time Machine is really only a problem on laptops.

I have two desktop Macs (a Mac Mini and an iMac) which rarely present problem with backups. Time Machine just works! But then, a) it is easy to keep an external drive connected for backup purposes, or if using a networked drive the machine is on a wired network connection, so there won’t be any network problems, will there? Similarly, if I connect an external drive to my MacBook, or use a wired connection (and disable wifi to ensure the wired connection gets use!) then backups complete more quickly (as I’d expect) and more reliably. But who wants to do either of those with a portable computer?

Conclusion 4: Time Machine as currently implemented is not fit for purpose for use on laptops without radical change.

Why? Because one doesn’t want to connect external drives or wired network connections to a laptop. Besides, a laptop is not left to run all the time - one uses it, then closes the lid to preserve the battery. Or if you don’t close the lid it will go to sleep anyway. When the laptop sleeps (or, more accurately, gets to a certain level of sleep), the wifi hardware is powered down, and the connection is lost. It is my hypothesis that a) with smaller SSDs taking less time to backup, this used to be less of a problem because for any given pattern of use there is a smaller chance of interrupting a backup than with a larger SSD, taking longer to backup. Further, I hypothesise that SMB is more susceptible to network interruptions than was AFP.

On the assumption that I am correct, it follows that Time Machine is not fit for purpose on a MacBook because instead of completing multiple backups per day it is frequently not possibly to complete a backup for multiple days (or weeks!) at a time without making special provision for the machine to be left online and on power whilst the backup completes - which negates the whole point of Time Machine - that it should just work reliably in the background without the user being particularly aware of it.

In order to fix this, Apple need to come up with some way of achieving a session-level connection between the MacBook and the networked disk that is tolerant of (or capable of dealing with) interruptions to the connection.

If there’s anyone in here from Apple, I’d love to talk to you about it! :slight_smile:

Colin

23

Okay, those are hypotheses :grinning:

TimeMachine is the Windows ME of Mac software. Much like Apple Mail, I can only assume that none of the developers actually use it.

For me, it fails every six-nine months, requiring starting over. This is true whether on my NAS, or on directly attached drives.

I stopped using it a couple of years ago.

1 Like
24

This is not mere speculation, and it is the root of the problem, as researched and documented by Howard Oakley.

1 Like
25

Thank you for that link - it’s nice to find one’s speculation confirmed by so eminent a source! :slight_smile:

Meanwhile, my solution on my MacBook (and it’s only a partial solution, but it certainly helps) is to keep as many of my files as possible on my Synology NAS using the Synology Cloud Station Drive software. This is, in effect, a personal dropbox service, but with the data stored on my NAS rather than in the cloud. This set of data is also shared (synched!) on one of my desktop Macs, which saves it via Time Machine, whilst the MacBook excludes it from Time Machine. This means that the Time Machine load on the MacBook is much reduced. It’s far from perfect, and I’m aware of its shortcomings, but it makes things a little more usable! Fortunately my data isn’t particularly fast-moving …