Catalina and whether to Partition or create Volumes on a 4TB SSD: What to do?

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Catalina and whether to Partition or create Volumes on a 4TB SSD: What to do?

I mistakenly asked this question in the incorrect community, so please pardon the reposting.

I've seen the question asked before and read all of the responses, but none of the responses seem to address this issue.

For many years I have partitioned all of the drives in every computer I have owned. I decided to do this to protect all the data on my computers from applications like Adobe Photoshop. Photoshop went crazy one day and overwrote key system software when the assigned scratch area was full, however since I had partitioned my drive not one bit of data was lost on any of the partitions. Every client design project was protected; all my various media files were in tact, my iTunes, Photos & iPhoto libraries which were redirected to a partition were in perfect condition and email that I had directed to a non-system partition was all saved from corruption and loss.

The startup partition was mostly toast, and only some files were recoverable.

So, the question is this:

Will creating VOLUMES on a 4TB SSD provide the same protection that isolating files on a partition would provide on the 4TB SSD and is partitioning on a SSD as protective as on a mechanical drive that is partitioned, if the operating system or the boot volume was hopelessly corrupted.

Of course the question is exclusive of a situation in which either the entire SSD or mechanical drive were to have a massive catastrophic failure.

On more than one occasion, I've had Adobe applications wreck havoc on my boot/system partition, but repeatedly the data stored on the other partitions was unaffected, and only the boot/system partition needed rebuilding. While it is always a pain to restore a corrupted drive, having the partition protected data made the task much easier on the several occasions when I had to rebuild a corrupted boot/system partition.

MacBook Pro with Touch Bar

Posted on Nov 1, 2020 6:25 PM

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Answer 1

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Halliday

Level 4

2,677 points

Nov 1, 2020 9:00 PM in response to BinsuJiro

Especially since your question pertains to Catalina, BinsuJiro, the answer is, don’t worry about it.

Here’s why:

Catalina already, by default, creates separate Volumes for your Operating System (OS), usually named “Macintosh HD”, your Data (including your installed applications), usually called “Macintosh HD - Data” (this is actually the disk that Finder calls “Macintosh HD”), Virtual Memory (VM, and called “VM”), Preboot and Recovery Volumes (which are, usually, not even mounted).
The OS Volume (the “boot” Volume, unless you wish to consider the Preboot Volume to be the “boot” Volume) is set to Read Only, so it can’t be overwritten, even by the most errant of processes.

You can, however, choose to create further Volumes, using Disk Utility, to further isolate projects, or whatever, within the Catalina Container disk.

One of the benefits of this Volume scheme, in Catalina, is that all Volumes share a pool of Available (and Free) space, and automatically adjust during use. (Note: Available space is always greater than [or, potentially, equal to] Free space. Available space equals the sum of Free plus Purgeable space. Purgeable space is space that is temporarily used by the OS, but can be purged, as needed, for other purposes.)

This shared pool of Available (or Free) space is most efficient on SSDs, since the non-linear character of SSDs is taken advantage of.

Does this help address your concerns?

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Answer 2

Nov 1, 2020 6:28 PM in response to BinsuJiro

IMHO, partitioning a drive is an old concept based on the slow speed of rotating drives. Large SSDs are fast enough that partitioning is not required. The same separation of data can be achieved by the creation of folders/directories.

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Answer 3

BinsuJiro Author

Level 1

19 points

Nov 1, 2020 8:12 PM in response to BobTheFisherman

Bob,

Thank you for your opinion. I understand how the speed of rotating disks had been a consideration, but my concerns are about saving as much data as possible from catastrophic failure.

When on a partitioned drive the boot partition is trashed all other data on the other partitions is safe, unless the drive gets run over by a truck or falls out a window :-).

My question concerns how isolation of a 4TB SSD into partitions or optionally volumes compares with isolation of data on partitioned traditional drives.

I guess I could have redundant network access storage with a multi-drive NAS, but that is an expense I'm not ready for yet. I currently use Retrospect backups of everything, but prefer the benefit of isolating data in partitions or volumes, so only the boot partition needs to be rebuilt.

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Answer 4

Halliday

Level 4

2,677 points

Nov 1, 2020 9:12 PM in response to BinsuJiro

By the way, BinsuJiro, I would hope that you recognize that partitioning, on a spinning disk, does not provide as great a form of protection as would separate drives: there are no physical barriers to the write head simply skipping along the disk surface.

Partitioning is a purely software based process.

It works OK, only so long as the software “obeys” the software defined “boundaries”.

(This is similarly true on SSDs, of course.)

(In my four decades of working with computers, I have seen many sorts of failures!)

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Answer 5

BinsuJiro Author

Level 1

19 points

Nov 2, 2020 2:06 PM in response to Halliday

Halliday,

Thank you for this detailed explanation. I understand your information and that partitioning is not a guarantee that untoward events might happen at any time.. I particularly appreciate the technical details you provided.

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Answer 6

BinsuJiro Author

Level 1

19 points

Nov 25, 2020 1:06 PM in response to Halliday

Thanks to all who contributed to my question. For everyone's information, this is how I resolved the issue:

Because I wanted to use FontExplorerPro(FEX) to manage my fonts and I wanted to remove FontBook along with unnecessary fonts installed by the system to make them loadable by FEP. I created two partitions so that I could load a second iteration of Catalina on my new 16" 4TB MacBooK Pro.

I used the second installation of Catalina to remove FontBook and the unnecessary fonts from the first installation.

Then, in order to maintain my file and workflow strategy that I have been using for many years. I created volumes with the remaining space to match the Partition scheme on my old 17" MacBook Pro. I can now have matching volumes and partitions, so that I can mount the partitions from my MBP 17 alongside my volumes on my new MBP 16.

I'm migrating all my design work files to the new MBP, but still using the old MBP, so with this method I can sync the data on both machines easily while the migration continues.

It may sound convoluted to some, but it works for me, and in deference to Halliday's comment on data security and preservation, I will most definitely be looking into a multi-drive NAS to enhance data security in addition to my daily Retrospect backups to an external drive.

Thanks,

Vincent

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