I have a Samsung external drive, 2TB, about 4 yrs old; use it for Time Machine backups only. Thinking after 4 yrs & a new iMac, might be time to replace. Worked perfectly to set up the new iMac, but…
The last few days, every so often a scheduled (hourly) Time Machine backup isn’t completed; no error message, just a message that it couldn’t be completed. If I manually tell it to backup, all goes well. Already spoke to Apple & the only suggestion was that the drive might not be 100% compatible w/the new iMac.
Any suggestions for a newer external drive?
I now use a Samsung T7 SSD for Time Machine backups but also continue to use an “old” hard disk. Time Machine happily supports more than one external storage device (hard disk or SSD) and alternates backups between them when they are connected to the Mac.
If you have not already done so, you should consider using Disk Utility to “Repair” the hard drive.
There are some discussions about TM drives on this website. Try searching for SSD.
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Thank you. Mine is also a Samsung T7 SSD. Apple said it might not be 100% compatible as the iMac has the M4 chip & the SSD is 4 yrs old. I’m not techie enough to understand if that might be an issue.
Did search TidBits for SSD but there were close to 150 results, hard to cull thru.
Will try disk repair, didn’t think of that. Thx for the suggestion.
Rule 1: Don’t buy a ready-made drive. Buy enclosure and disk separate.
Rule 2: Get an NVMe SSD. They’re quiet and more reliable than any HDD. Avoid anything SATA.
Rule 3: Don’t over-spec. TM i/o is throttled so no need to get the fastest flash. Get something that has a decent reputation and does ≥500 MB/s.
Rule 4: For the enclosure, TB is not required due to speed (for reason see above). 10 Gbps USB3 is perfectly adequate for TM. However, if you for personal reasons absolutely want to have access to SMART, you’ll need TB4/USB4. SMART access is not supported on Macs over USB3.
Here’s a decent USB3 enclosure with a good rep for $16. And here’s 4 TB of Samsung flash that’s reliable and perfectly adequate for TM for just $250. No skills required to assemble.
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Very much appreciate the response but it’s over my head. 
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This makes no sense. A Samsung T7 is a 10Gbit/s USB device. It should be compatible with literally everything that has a USB port, including a modern Mac.
The person from Apple who said this obviously doesn’t know what he’s talking about. Or he’s trying to sell you a new SSD and is hoping you won’t think too much about what he’s saying.
Absolutely true. It is so trivially easy to build your own USB or Thunderbolt SSD that it really doesn’t pay to buy a ready-built external unit unless you have a need for some feature beyond mass storage (e.g. a unit with a PIN-pad for additional security).
But for basic storage, just build your own. Build an SSD (for performance) if you need 2TB or less. Build an HDD if you need more capacity on a single device (e.g., my backup devices are 4TB HDDs).
It really isn’t. It is trivially easy to install an “internal” SSD or HDD into a USB/TB enclosure. You’ll save money and will probably end up with a better quality device.
I know it connects correctly w/the new iMac, it has the Time Machine files from my previous MacBook & was used to set up the new iMac so it should be compatible. But Apple support said it’s possible the glitches I’m running into might be due to the iMac having the M4 chip. They weren’t trying to sell me anything or suggesting an alternative drive. I don’t know enough about the M4 chip compared to what my MacBook had to argue about it.
It will still do Time Machine backups (set up as automatic, hourly) but several times/day there is an error message that the backup couldn’t be completed, no error message as to why. Apple confirmed all my settings are still correct so the only suggestion offered was to try a more up-to-date SSD.
I think Apple Support is doing a bit of miasmic handwaving. 
It’s certainly a good idea to replace your backup chips/discs every 5 years or so. We all think hardware should last for at least several decades because it’s after-all hardware but we would be wrong.
I would consider going into the TimeMachine prefs and removing ( the minus sign ) that drive; erasing it in Disk Utility; and reassigning the “new” disk as your TimeMachine backup. With a T7 it will take an astonishingly short time to back up your spiffy new iMac.
If you still are getting errors after a week or so, it’s time to get a new one and @Simon & @Shamino 's advice is excellent. (You, too, can plug a chip into a socket and close a cover. Really!)
Dave
Tomorrow morning I will do as you suggest; I will erase the drive & attempt to start over. Since I already have the new iMac up & running for a few weeks and I have Backblaze, I’m willing to try the current SSD from scratch. If it works great, all will be well. If it continues to have glitches a few times a day, I’ll know it’s no longer working well & will replace it, possibly w/another of the same drive. I’ll see what happens.
I did try calling Samsung to ask if the current T7 SSD has any issues w/Apple’s M4 chip. Didn’t get a very comforting reply; was told it will probably work & if it doesn’t, I could return it. Would prefer to know ahead of time that the products will work together. We’ll see what happens tomorrow.
Excellent! Backblaze, too! You are a prudent person!
Oy.
Your willingness to sally forth into Tech Support hell is splendid! It’s really worth trying because they’ve got the data. (I would be in heaven for access to Apple’s Genius bar database .)
That said, probably work is silly. It’s been available for years, adheres to the USB standards, from a major vendor, what’s this probably work crap? 
Good luck!
Dave
Yes - see this discussion:
Here are some photos of the steps to preparing an NVMe M.2 SSD
The parts (SSD at top)
Insert SSD in the connector
Scew down the top cover
Attach a USB-c (or Thunderbolt) cable
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Just want to say a Time Machine drive doesn’t necessarily have to be a SSD. Buying a close replacement for your current drive is fine, of course, especially if you like how it runs. But a “traditional” HD will give you more storage space per dollar spent…and, personally, I’m not that bothered by not having SSD speeds for backups.
Here’s another recent thread you might find helpful:
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Thank you @Halfsmoke I was just about to say this. There’s no shame in replacing an HDD with another HDD and it’s the least expensive option. (Also it is the only way to get enough storage space if you need a lot, such as my current 12TB drive.)
To answer the original question, I’ve had good luck with external Western Digital drives. The last one ran 24/7 for over five years before it started making noises that made me nervous about its future.
This is corporate CYA nonsense. They can’t just say “yes” because if there is some unknown glitch, you might go to the press and lawyers and start a large embarrassing multi-billion dollar class-action suit.
So they will never give you a definite answer about anything, unless (maybe) your computer is an exact match for one they used for product testing.
I’ve long since come to the conclusion that customer support organizations (from all corporations) are a complete waste of time. You spend hours on hold talking to someone who is only authorized to read from a script. They should just publish the script and shut down their support organization altogether - the result would be the same and it would cost less.
I build my own external HDDs. I buy an internal 3.5" drive and a USB enclosure. Key things to look for when selecting a drive are:
- Rated for 24x7 operation. For something like Time Machine (making backups every hour), this is something you want. Many lower-cost consumer drives are designed to be installed in computers that are powered-off when not in use.
- 7200 RPM. Slower drives (5400 RPM and others) won’t perform as well. Faster (10,000 RPM) will perform better, but I don’t think it’s worth the extra cost and heat unless you’re configuring a server.
- CMR recording. You don’t want to use SMR recording, even though it costs less, because SMR has very poor performance when writing a large amount of data (e.g. during a backup).
When shopping for an enclosure, look for one with a cooling fan. HDDs (especially high performance ones) can get hot under load and if they overheat, they will thermally-throttle (pretty much eliminating all throughput until it cools down).
There are lots of choices within these criteria. My most recent drives (put in service in 2020) are using:
- Toshiba N300 drive. I’m using the 4TB models. These are designed for use in NAS systems (24x7 operation, vibration resistant) and have worked well for me. But they are a bit noisy compared to other brands.
- Vantec NexStar HX enclosure.
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Your comments about customer support & reading from scripts is 100% the problem. While I was still trying to ask Samsung questions, he kept telling me about shipping costs, how soon I would receive the drive, etc. I asked him to please stop trying to close the sale while I was asking questions. His response: I would have 15 days to return the drive if it wasn’t what I wanted.
I get that from everyone’s customer support these days. I’d like to know a product fits my needs before I buy it, not after I receive it. I realize return shipping is generally free but it’s a pain to deal with. Enough is enough!
I have what I believe is a related question. After a number of problems with my external hard drive, I began using an OWC Envoy drive for my Time Machine backups with an iMac M-1. (I was not adventurous enough to assemble my own, though this thread is great and I will do so in the future).
Performance is great. Original backup of entire drive was very fast and incremental backups also seem fast. I have always had great luck with OWC products.
Here is my question. When my iMac is asleep, after I log back on, I receive the message that my Time Machine backups are paused. When I log back in, I select “back up now” in TM and the backup takes place and continues while I am logged on. Is it normal TM behavior to attempt and then pause the backup when my computer is in Sleep mode? Should I change any settings so that TM knows not to attempt backup if the iMac is in sleep mode?
Thanks for the help.
GM
That’s the exact problem I’m having & why I started this thread, but it’s only happened since I began using my new iMac a few weeks ago; was never a problem w/previous Macs. Previous Macs ran Time Machine hourly, even when Mac was asleep. I thought maybe a Time Machine setting had been “accidentally” changed when I moved everything to the new iMac so I contacted Apple to help figure out what had happened.
Did a screen share & had the call escalated, no problems were found. No explanation was offered as to why this was happening, claimed they hadn’t heard of this before. That’s why they suggested the problem might be w/my SSD; maybe it wasn’t up-to-date enough to function properly w/the new M4 chip.
From responses here, doesn’t seem to be the SSD but I still can’t figure out why this is happening. Might replace it anyway just to be safe as it’s 4 yrs old but appears that might not solve the problem. Sorry you’re having this issue as well but I will admit I feel a bit better knowing that I’m not the only person who’s seen this.
I agree with others, Apple person is handwaving. I have two M4 Macs, the M4 Mac mini and an M4 MacBook Air. I have two Samsung T7 SSD for use with each Mac. They work just fine. I did reformat the T7s to APFS.
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Sorry for the vagueness, but I recall reports in other forums that Sequoia may have introduced some changed behaviors involving sleep and Time Machine. I don’t recall any particular solutions. Might be worth investigating.
That’s what I’m beginning to suspect. Even mentioned the possibility to Apple escalated support. But, they’re holding firm; didn’t happen, not the cause.