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kcrossley

macrumors regular
Original poster
Mar 22, 2009
170
26
Virginia
Hi guys. I need a little help.

I have an iMac Pro with (2) Samsung 990 Pro M.2 SSDs. I use the internal Apple 1TB SSD for the Mac OS and my apps, (1) Samsung 990 Pro 4TB external SSD for my client files, and (1) Samsung 990 Pro 4TB external SSD for my media. I probably use about half of the 9TB of total storage space. I use Backblaze for daily cloud backups but don't have a local backup solution.

My understanding is if I want to back up all three drives with Time Machine, I need at least three times the space I use, which would be about 12TB. One of the reasons I got away from Time Machine a few years ago was that the external G-drive I used kept disconnecting from my iMac Pro when it went to sleep, making the backups unreliable.

I have two questions. Has that problem been resolved with Sonoma 14.5, and what 10-12TB external drive would you purchase to use with Time Machine? The fastest external port on my iMac Pro is Thunderbolt 3, but I suspect that a traditional hard drive will have much slower transfer speeds than the Thunderbolt 3 port. I also have a Synology 1512+ sitting around that I may be able to use, but it's so old that it's limited to DSM 6.0.

Once again, any help and/or advice is very much appreciated.
 

leifp

macrumors 6502a
Feb 8, 2008
516
494
Canada
If you’re backing up to HDDs the port speeds are unlikely to matter overmuch, not least because backup speed only matters when using it to restore. As long as you’re not using USB 1.1 ;)

Personally, I would use the 1512+ unless you want it to do more than just act as a local backup. Although I don’t know if you can still use that setup with Time Machine… (I have a newer Synology setup)

As to the “three times the space” requirement, I have found no evidence of that at all. I have used a 4TB backup on my 3TB main drives in the past and have a 4TB backing up my 4TB on a secondary machine. While the drives were never “full” they are well over half (that 3TB machine had 2.4TB used, so the backup was less than double the size) and I never had an issue with Time Machine.
 
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pshufd

macrumors G4
Oct 24, 2013
10,133
14,562
New Hampshire
I have a Mac Studio as my primary system and it has an internal 512 GB and an external nvme 4 tb. The internal is normally 60-80 percent used and the nvme is about 60% used. I backup to a WD Elements 8 TB HDD. This has been my normal practice for the past 18 years or so with different systems and storage sizes. I plan to get a second backup drive 12-16 GB by the end of the year to have two backups. I originally wanted to get an Ultra Studio for the RAM and additional SSD but they were sold out at my three local Apple stores. I might replace my M1 Max with an M4 Max with additional RAM and Storage if they launch something this fall but I don't expect a new Studio until next year.

My iMac Pro is fairly recent and I was giving some thought to making it my primary as it has a larger internal SSD. This would mean that I'd need a Time Machine for that system too. I backup the base system files from the Mac Studio to my M1 Pro MacBook Pro as well so I have a lot of backup files on two other Macs.

The Time Machine backup runs through one of the USB-A ports so we're talking USB 3 speeds. I find that fine for my purposes.

So I have about 2.5 times the space on the Time Machine disk compared to what I use. I had never heard the 3x storage rule before. Time Machine works with versioning so it would expire older versions as you used up more space but maintain a current snapshot as priority., I can see wanting three times storage if you delete large files on a regular basis that you need to retrieve but I tend to accumulate more of them on the large, external SSD so I don't really delete large files a lot outside of virtual machines and those are good to mark for not backing up.

I bought the WD Elements back in 2020 so it was used as backup for my 2015 MacBook Pro, then my M1 Mac mini in 2021 and then the Studio later on. I have not had the disconnection problems that you referenced on the HDD. I did have some of these on the 4 tb nvme SSD when I originally bought it but the problems went away after a few months. This was under Ventura. It's possible that it was due to heat or a Ventura bug. There are a ton of problem reports on external nvme drives disconnecting since about 2019 and I don't know if the general problems have been resolved but I haven't seen the problem personally for about a year.

One additional note is that I bought one of these drives in 2019 and it lasted about 18 months. I assume that I got a bad one or that they had a bad batch. It happens. Sometimes these things last 15 years and sometimes they last a year or two.
 

specialstyle

macrumors member
Aug 21, 2024
75
20
Hi guys. I need a little help.

I have an iMac Pro with (2) Samsung 990 Pro M.2 SSDs. I use the internal Apple 1TB SSD for the Mac OS and my apps, (1) Samsung 990 Pro 4TB external SSD for my client files, and (1) Samsung 990 Pro 4TB external SSD for my media. I probably use about half of the 9TB of total storage space. I use Backblaze for daily cloud backups but don't have a local backup solution.

My understanding is if I want to back up all three drives with Time Machine, I need at least three times the space I use, which would be about 12TB. One of the reasons I got away from Time Machine a few years ago was that the external G-drive I used kept disconnecting from my iMac Pro when it went to sleep, making the backups unreliable.

I have two questions. Has that problem been resolved with Sonoma 14.5, and what 10-12TB external drive would you purchase to use with Time Machine? The fastest external port on my iMac Pro is Thunderbolt 3, but I suspect that a traditional hard drive will have much slower transfer speeds than the Thunderbolt 3 port. I also have a Synology 1512+ sitting around that I may be able to use, but it's so old that it's limited to DSM 6.0.

Once again, any help and/or advice is very much appreciated.
I'm in a similar boat -- I haven't had the disconnect issue but in terms of backing up those client drives I would suggest getting something a little more robust. Time machine is great, but I have had instances where the backup is corrupt or unavailable and....lets just say I'm lucky I had copies.

I'm currently in the middle of pricing out a new Synology NAS because those come in a variety of sizes and the 4-5 bay models are beasts. For my line of work (video editing, lots of graphics stuff, pictures etc) I want the drive redundancy -- and to back that up I would look into Crashplan for business because they support NAS drives and unlimited backup. BackBlaze does not... I have it right now too.

Having the NAS is going to make upgrading a lot easier since the drives are pooled, you can swap in and swap out as needed.

Just a little food for thought! Hope that helps good luck
 

kcrossley

macrumors regular
Original poster
Mar 22, 2009
170
26
Virginia
If you’re backing up to HDDs the port speeds are unlikely to matter overmuch, not least because backup speed only matters when using it to restore. As long as you’re not using USB 1.1 ;)

Personally, I would use the 1512+ unless you want it to do more than just act as a local backup. Although I don’t know if you can still use that setup with Time Machine… (I have a newer Synology setup)

As to the “three times the space” requirement, I have found no evidence of that at all. I have used a 4TB backup on my 3TB main drives in the past and have a 4TB backing up my 4TB on a secondary machine. While the drives were never “full” they are well over half (that 3TB machine had 2.4TB used, so the backup was less than double the size) and I never had an issue with Time Machine.
I was thinking about selling the 1512+ and getting a Synology DS923+ instead to use with Time Machine, PhotoStation, and Plex. What Synology are you rocking?
 

leifp

macrumors 6502a
Feb 8, 2008
516
494
Canada
I was thinking about selling the 1512+ and getting a Synology DS923+ instead to use with Time Machine, PhotoStation, and Plex. What Synology are you rocking?
That’s the one. Bothered me a bit to lose on device (hardware) resolution scaling for video, etc but otherwise doing a great job for those very tasks.
 

kcrossley

macrumors regular
Original poster
Mar 22, 2009
170
26
Virginia
I managed to score a blow-out deal and have 16TB Seagate IronWolf HDDs, substantially more than present use cases require. Lots of room for growth, though!
Did you get two or more? Is the blowout deal still available? :)
 

leifp

macrumors 6502a
Feb 8, 2008
516
494
Canada
Did you get two or more? Is the blowout deal still available? :)
I picked up 5 drives. It was over a year ago, though. I’m in Canada, so it was from CanadaComputers.com but large networks (e.g. Newegg) will have such deals occasionally.
 
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