What size external SSD backup drive for bootable restores?

[Marty_Macfly]

Hi all,

more newbie questions.

What size external SSD backup drive for bootable restores?

I’ll be getting a 512GB sized memory M1 Mac book air next week.

Figure in the Xmas sales, I’ll treat myself to an external SSD backup drive. The drive will primarily be for a bootable restore of the MacBook. For example if the MacBook dies completely, I get a replacement from Apple, and then hopefully use that external drive to do a full restore snapshot of my MacBook.

Thing is, I will also be doing Time Machine backups. So I imagine that would also go on this same external drive.

So with that in mind, what size drive should I go for? 1TB? 2TB?

No idea how much space Time Machine backups take. Is it compressed files, or are Mac files pretty much as compressed as possible?!

longer term, probably be looking at a much larger desktop HDD backup system. Keeping things small at the moment, so it might be a bit of a treat to have a small SSD external backup drive, and then eventually retire it to the emergency travel kit back up plan et cetera.

Hope you can advise

Best wishes

Martin

 

[ght56]

If I understand this correctly, do you want to use this drive for both bootable clones (such as those made with Carbon Copy Cloner, which IIRC still does NOT work with M1 Macs) as well as Time Machine? If so, not knowing how much of your 512 GB SSD will be filled up and how you use the system, I would do 2 TB at a bare minimum, and lean towards 4 TB. 4TB would hurt the wallet a bit more, ranging from about $450 to $750, but you would be able to hold a lot more incremental snapshots than you could with a 2 TB SSD, as more than 1/4 of a 2 TB SSD would have to be used for your clone partition. Additionally, with 4 TB, you could also make a third partition you could use for general storage and as scratch disk space and still have plenty of room left for the Time Machine partition.

After you decide the size, there are several other considerations worth mentioning.

 

[hobowankenobi]

I would not waste $ on SSD for TM. I would get a largish HD, dedicate it to TM. 2TB or so. And a 500MB SSD for a dedicated clone.

 

[honestone33]

I have 2 Samsung 850 Pro 512 gig SSDs inside Orico Enclosures. For each of my Macs (a late 2018 Mac Mini, with a 256 gig SSD, and an early 207 Mac Book Air with a 252 gig SSD), I am using less than 80 Gig of space. So, for each of those external SSDs, I have 3 partitions on each: 2 of those partitions are 100 gig in Size, and are for SuperDuper! backups for each of my Macs (SuperDuper! is similar to Carbon Copy Cloner, but it is not yet compatible with Big Sur). Obviously I have to carefully manage the amount of space I am using on each of my internal SSDs, but I do that.

 

[hobowankenobi]

FYI: TM will continue to use space as it keeps versions on files. More space = more versions (history). Generally, one should have a minimum of double the space for TM as what is being backed up. OS 11 with snapshots may improve on that...but traditionally, TM needed room to breathe.

 

[Fishrrman]

"What size external SSD backup drive for bootable restores?"

If the backup is to be a bootable cloned drive, then it can be "the same size" as the internal drive.
Thus, if your internal drive is 1tb, a 1tb external drive will be fine.

My cloned backups NEVER "get larger" than the source drive...

 

[honestone33]

"What size external SSD backup drive for bootable restores?"

If the backup is to be a bootable cloned drive, then it can be "the same size" as the internal drive.
Thus, if your internal drive is 1tb, a 1tb external drive will be fine.

My cloned backups NEVER "get larger" than the source drive...

True, but it's always better to have some "breathing" room. For my two SuperDuper! partitions on my 2 external SSDs, they are only 25 gig more than the source.

 

[AppleSmack]

Hi all,

more newbie questions.

What size external SSD backup drive for bootable restores?

I’ll be getting a 512GB sized memory M1 Mac book air next week.

Figure in the Xmas sales, I’ll treat myself to an external SSD backup drive. The drive will primarily be for a bootable restore of the MacBook. For example if the MacBook dies completely, I get a replacement from Apple, and then hopefully use that external drive to do a full restore snapshot of my MacBook.

Thing is, I will also be doing Time Machine backups. So I imagine that would also go on this same external drive.

So with that in mind, what size drive should I go for? 1TB? 2TB?

No idea how much space Time Machine backups take. Is it compressed files, or are Mac files pretty much as compressed as possible?!

longer term, probably be looking at a much larger desktop HDD backup system. Keeping things small at the moment, so it might be a bit of a treat to have a small SSD external backup drive, and then eventually retire it to the emergency travel kit back up plan et cetera.

Hope you can advise

Best wishes

Martin

If you have your bootable clone and TM on the one drive, you really only have one backup. Drive failure = both backups gone.

Time Machine doesn't compress files, though incremental duplicates take up no space if that helps.

I'd suggest bootable backup SSD of 0.5 to 1GB - depends if you want versioning or not.

For TM, minimum of 1TB will do. In my case, a 2TB external for 1TB internal gives me almost 2 year's history with large design files. If you can afford an SSD for TM, go for it, it'll be much faster. People will warn you about SSD wear, but the stats say that's not an actual problem in your computer's lifetime.

 

[honestone33]

If I used Time Machine, and especially did incremental backups, and also wanted to continue to use SuperDuper! for 1) ease and smoothness of a quick recovery, and 2) doing a clean, fresh installation of a Mac OS, I would have 2 external devices: one of them an SSD with a small enough capacity to accommodate a SuperDuper! backup, and another larger HDD to handle Time Machine and all its incremental backups.

Alas, in my case, I don't need incremental backups (actually can do it with the paid version of SuperDuper! (which I have)), and thus do not need Time Machine.

 

[honestone33]

Hey Marty_Macfly, fantastic user name! Have always enjoyed all 3 of the "Back to the Future" movies!

 

[cdcastillo]

I would not waste $ on SSD for TM. I would get a largish HD, dedicate it to TM. 2TB or so. And a 500MB SSD for a dedicated clone.

This, this is right.

 

[hobowankenobi]

I too would use the scheduled, incremental of SuperDuper over TM. One thing nice about TM backups is the ability to use them with the Migration Assistant. Other than that...no feature or advantage to TM over SuperDuper, CCC, Chronosync, GetBackup, etc.