Need advice re drive for Time Machine

I have a 2TB TimeCapsule (TC), about 8 years old, I’ve been using for TimeMachine ™. Since I got my eero mesh, the TC is no longer my router, but connected via ethernet to the eero it’s still my Time Machine, which backs up 2 Macs, my wife’s and mine (which is why it has to be connected to our home network, not wired to one of the Macs). Over the past couple of years TM has been buggy (never was 100% reliable, but still usually helpful). My backups occasionally need to start all over (and the past gets lost), but my wife’s, on the same disk, have had no such problem. I suspect it’s no-longer-young disk is becoming worn in the place where my backups reside - though it might be a software problem on my Mac.

2 Q’s:

  1. I’d like to check the health of the TC’s disk, but I haven’t found any way to do that, using, for instance, TechTool Pro or somesuch. I’ve tried to connect it via ethernet to my Mac, but it doesn’t mount on the desktop nor is it registered by Disk Utility. Is there a way?
  1. If I simply assume the TC’s disk has become faulty (though, curiously, only on my backups, not my wife’s) and I replace it with something else to use as TM, what is best to use? Do I need an NAS device, or will a simple external HD (which needs an ethernet port so I can connect it to the eero, which has no USB port) work?

I’m not sufficiently tech-savvy to sort all this out, and would appreciate any help/advice.

If you want to replace the hard drive in your Time Capsule, it is possible, but a bit tricky. Definitely easier than working inside an iPhone, but this may be more work than you’re prepared for.

If you decide to do that, I would suggest getting a big drive (or even an insanely big drive) since your storage requirements have probably increased over the last 8 years. Just be sure that whatever you get, it is rated for 24x7 operation, since that is how it will be operating in a Time Capsule.

Another option, if you have a Mac that is powered 24x7 on your network, you can attach a USB or Thunderbolt storage device and configure it as a network Time Machine storage device using the Sharing system preference panel. See:

I don’t know about Big Sur, but I checked my system (running Catalina) and the option is there.

Of course, if you don’t have a computer that’s powered and connected to your network 24x7, then this won’t be a viable option. On the other hand, a minimally-configured Mac mini (especially an older model that you may be able to get for closeout prices) might possibly be an affordable option.

If there are other options for Time Machine compatible network storage, I’m afraid others will have to provide those suggestions. I haven’t ever investigated those options for my network.

1 Like

Apparently I wasn’t clear. I wouldn’t want to replace the drive in the TC, I’d want to ditch the TC entirely and replace it with a HD connected to my home network, and use it as a TM to back up 2 Macs - one still with Mojave, and one with Catalina. But thanks anyway.

Time Machine Server does still exist in Big Sur (I like the way Apple now has a menu selector for system version in the User Guide, but they really should add screen shots, I keep having to make my own for users confused by text):

Back up to a shared folder with Time Machine on Mac - Apple Support

I helped a user set this up a few months ago when he wanted to start using his apartment building wifi instead of comcast. The TC was at least 7 years old and the drive was well past its typical lifetime anyway, so I had him stick it in a closet as an archival backup and get a spinny hard drive for time machine server on his 2012 mini. It’s been working out well for two minis and two macbook airs (all on Mojave).

As for Time Machine occasionally eating a backup so you have to start again from scratch, that’s not a disk problem but a many years now time machine problem. It’s one reason why you really need to have at least two separate kinds of backups, preferably three. Or five. But at eight years old, you really should replace the drive because it could fail at any time and it’s likely already slowing down from read/write retries. Since Murphy watches over us your main computer drive will fail simultaneously.

Another possibility is a small NAS ethernet wired to a switch connected to your modem/router. Get an empty box and put your own drive in so you know exactly what you have. But they need some management so there’s an extra learning curve of varying steepness per situation. The consumer (affordable) ones are too slow to do their own encryption tolerably, but Time Machine will be doing that on the Mac so it shouldn’t matter for backups or media serving of non-sensitive things. Some have an unpleasant ‘feature’ that that they won’t reboot unless connected to the network so they can phone home for updates, and you have no control over that. Personally I much prefer mac minis as servers, but used ones are getting hard to find and cost as as much as they did new.

1 Like

It might still exist but don’t work worth a darn. After mucking about with it for 3 or 4 weeks…I gave up and disabled TM o our laptops and set up CarbonCopyCloner jobs to a folder on the two failed tam server machines instead…and that just works including mount and dismount of the appropriate shares on the two destinations…one on Big Sur and the second still on Catalina since I’m waiting on OWC to update SoftRAID for my TB3 RAID drive.

I used to back up to a hard drive connected to an AirPort Extreme. The iMac never had a problem backing up to it, but Time Machine would often report my MacBook Pro’s backup had problems and start over. I think Time Machine wasn’t able to always deal with me closing the lid and putting the computer to sleep in the middle of a backup. This problem seemed to go away when I set the computer to back up only when connected to power.

In January, I replaced the AE/HD combo with a Synology DiskStation. It was an expensive solution because I loaded it up with four 8-TB drives, but it has allowed me to consolidate data that had been scattered around on individual hard drives I had collected over the years. Also, I’m using a RAID 5 configuration, so I have some protection against a drive failure, which I didn’t have with my previous set-up. The DS can also do more than simply make storage available on the network, like act as a media server and a VPN server.

I think if you’re looking for storage that can connect via ethernet to your Eero, you’re essentially looking for a NAS. My set-up is probably overkill for you, but there are solutions that cost significantly less than what I ended up with.

Time Machine doesn’t have a client-server architecture, so it has long had issues with network-based backups that are interrupted. It’s one of the reasons I was never a fan of the Time Capsule.

Dave Hamilton of MacObserver once pointed out at MacTech that you could point Time Machine at a NAS using the btrfs (I think) filesystem, which supports snapshots. The advantage of doing that was that if your backup was interrupted and corrupted, you could roll back to a previous snapshot before the corruption, and Time Machine would just pick up from where the previous snapshot left off. I’ve never tried this, but it seems clever.

I’m interested in this subject both for myself and a client. The client is a nonprofit whose young interns are not good at the strenuous physical effort of plugging a USB drive into their laptops for regular backups. But their 2 TB time capsule keeps filling up. I want to figure out if we can attach a USB drive to the time capsule, which is a late model tall one, for backups.

For myself, I do time machine backups to an older flat model time capsule; when Apple announced they were discontinuing their routers, I bought the very last tall airport extreme because I like their routers, figuring that since the interface is proprietary it’s less of a security risk than the ordinary consumer router. I use the airport extreme as my router, and the older time capsule just for backups. Eventually the drive in the time capsule will go belly-up at which time I’d like to attach a USB drive to my airport extreme for backups. Note, I also back up to an external USB drive attached to my computer using CCC. And yes, I realize I can use CCC and not TM for network backups, but would like to spread out the responsibility.

So I’m interested in any experiences readers have hanging a USB drive off a time capsule/airport extreme for use with either TM or CCC.

I’d like to hear something about this, too. I’ve tried attaching a USB drive to my TC (which backs up two Macs over WiFi), but it doesn’t register anywhere. I don’t understand that, because why else would it have a USB port? I thought, and I believe I’ve read, that a drive can be so attached, and used as additional storage, but I can’t get it to work.

Another note, though. You say their TM backups keep getting filled up. That’s curious, and sounds like a fault, because the TM keeps making backups until it’s full, but then erases the oldest to make space for the newest, and so on forever. So, in a way, it never gets filled up in the sense that it stops making backups. It may be, though, that they’re using a TC or drive which is so small that if too many interns all back up to the same drive, it only holds data going back a relatively short time.

Finally, there’s another problem with TM backups, mentioned earlier in this thread: the TM software is imperfect, with the result that every once in a while, not due to anything I’ve ever been able to trace, it loses everything and starts all over from scratch. So, at bottom, it’s sometimes helpful, but not terribly reliable. For reliability, you need at least one other backup mode (I use SD clones), and better would be two.

As for your client’s interns: if they need backups, each of them might invest in a cheap, big-enough, drive that they should always have plugged into their laptops. They probably don’t need to have one TM which backs up all the computers. That’s the only thing they’d have to remember doing, and they can surely learn to do that. That can be used for a TM; for clones, even regularly scheduled ones, so they don’t have to think about it; and maybe for both, if appropriately partitioned.

Attaching a drive should work for sharing files at least. Perhaps information here would help?

for my money and time, I’d go with CCC. Way more betterer than TM ever was for me.
I scheduled CCC to run automatically at 3am .
I use it with buss powered Seagate spinner (or WD, I forget).
I also use backblaze for all the other gak that isn’t boot drive and/or otherwise mission critical.

I believe that the original purpose of the USB ports was so that you could plug in a drive and back up your TC’s internal backup drive. This is an old memory that may be imperfect. I do seem to remember there were ways to get TM to recognize an attached USB drive, which is what I’m asking here.

I’m familiar with the concept of time machine pruning old backups to make room. This happens frequently on my own personal time capsule, and it works, although it’s very time consuming. We don’t even get that warning with the time capsule at the nonprofit. Maybe it’s because those are sparsebundles instead of a more straightforward kind of file system like a directly connected backup drive has. Who knows.

I’ve also had experience with corrupted time capsule backups. Not recently though.

“As for your client’s interns: if they need backups, each of them might invest in a cheap, big-enough, drive that they should always have plugged into their laptops.” I guess you missed the sarcasm in my comment about that. I keep recommending that but the trouble is enforcing the policy. It’s impossible to have one drive plugged in all the time—these are laptops that get moved around a lot, used on site and at home and at the office. The human element is the weakest and that is the problem here, and is the incentive for using the time capsule. For now, we are erasing all the backups and starting over, and I will only back up the important stuff which is mainly email (they use POP for everybody, making it doubly important. And yes, we discussed this and they have to use POP).


As I remember things, the purpose of the USB port in almost all legacy wireless routers was for connecting a printer, making the printer available to the network. Now that almost all printers have networking capability, that function is not needed.

It should be noted that given the relativeness slowness of printing, there was no necessity to go beyond the original USB specification. Thus if the ports worked with storage, access could be slow.

1 Like

The USB port was there so you should share an attached drive or share a printer. The AirPort Extreme can do this as well, but it’s actually only the very last model of the Extreme that Apple officially supported using the disk for Time Machine. You could get it to work with previous models, but it wasn’t officially supported.

Thank you! That does help me because my airport extreme is the last model.