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MacBH928

macrumors G3
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May 17, 2008
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Since hard drives are so large now, I tend to give them multiple partitions and use 1 Drive to backup multiple computers. For some reason I have this idea that the more partitions on a drive the more there is a risk of losing data or corrupting the HDD.

So is it ok to have 6-8 partitions on a single drive? Or is there a downside to it. Seriously, 4TB is so much for the average user. Most people will do with a browser, Microsoft Office, and maybe 20GB of media.
 
None that I am aware of.

Things to consider though:

  • The outer blocks have the best performance, so the first partition will be fastest, while the last partition will be slowest.
  • Since volumes on HDs typically need some breathing room for temp and cache files, swap space, and room for house cleaning....the more partitions one drive has the more space free space overall that should be reserved.

Or more simply....more partitions typically cost either free space or performance, maybe both.

I would not partition unless I need a different, bootable OS. Boot camp, or a second (different version) Mac OS are the most common uses.
 
I hate to say this... but that sounds an awful lot like Windows thinking - multiple partitions. IMO, there are few reasons to partition a large hard drive; boot camp being one of them, and possibly for running another OS. Otherwise, leave that large hard drive as a single partition. Another consideration is that SSDs are now formatted as APFS which further complicates the partitioning process.
 
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I hate to say this... but that sounds an awful lot like Windows thinking - multiple partitions. IMO, there are few reasons to partition a large hard drive; boot camp being one of them, and possibly for running another OS. Otherwise, leave that large hard drive as a single partition. Another consideration is that SSDs are now formatted as APFS which further complicates the partitioning process.

I’ve delt with multiple partitions in the past.
I see no reasons for multiple partitions at present.

Why not? If you had multiple computers do you back them up to the same partition??
 
I’m not sure the question being asked, but
Multiple computers to one partition, yes. Via time machine on a network drive.
Back one partition to another partition on same drive, definitely not. Drives fail, then you lose data and backup.
Best to backup to multiple hard drives.

As for multiple partitions on drive to separate or organize data. Not sure any value in that. On the Unixes, you can mount a partition or a drive as a folder, so multiple drives can look like one drive.
I believe partitioning got started when hard drives became larger than dos partitions. I once had a 900 meg drive back when max partition size was about 32 meg. Imagine all those partitions. I could go on, but.
Unix had concept of partitions prior to dos. Often, I believe, 1 for swap, 1 for system and 1 for user data.
 
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Question:
"Is it bad practice to have multiple partitions on 1 HDD?"

Answer:
No. Use partitions if you want and need them.

I've been partitioning drives and running them that way since the Macintosh SE30 days.

The internal drive on my 2018 Mac Mini is partitioned into four "pieces".
And ALL of them are formatted HFS+ (no APFS in this house!) !!
 
Question:
"Is it bad practice to have multiple partitions on 1 HDD?"

Answer:
No. Use partitions if you want and need them.

I've been partitioning drives and running them that way since the Macintosh SE30 days.

The internal drive on my 2018 Mac Mini is partitioned into four "pieces".
And ALL of them are formatted HFS+ (no APFS in this house!) !!

I’m curious, why 4 partitions? And what are they?
 
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Why not? If you had multiple computers do you back them up to the same partition??
You can make a disk-image for each backed-up computer, and then mount it while doing the backup. All those disk-images can reside on a single partition. Use sparsebundle or sparseimage format if desired.

You should then make backups of those disk-images, otherwise a single point of failure (the big HDD) will wipe out all the backups for all the computers.
 
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Yeah, it's pretty commonplace to have several partitions now, especially if you dual-boot.

The main downside that I can think of is just if your anticipated disk usage for each partition doesn't match the reality (e.g. if you expect you'll use two partitions equally, but instead one is almost full and the other empty). You generally can resize partitions, but there is some element of risk in that - I've done it several times without issues - and inconvenience if you need to merge non-contiguous partitions at any point.
 
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Hmm... One of my drives has partitions for each bootable installer from Leopard to Mojave, so 10 partitions there.
partition with archived installs for a lot of apps and utilities, which has all OS X/macOS installer apps and ISOs from Tiger to Mojave, including combo updaters for all Mac systems back to 10.2.8 (Jaguar), plus Windows installer ISOs for Win8 and three different "generations" of Win10 ISOs (plus backups of different versions of Boot Camp support files). Oh, there's also MS Office updates going back to the original OfficeX. Lotsa stuff on that one partition.
Plus 5 other partitions, mostly used for random backups for service work.
Oh, and three old full bootable backups of my main Mac, with 10.8.5, 10.10.5, and 10.12.6 - all with basically the same other software and old files relevant to that particular version.
So, 20 partitions on one 1TB spinner. Most of the partitions are less than 8GB in size.
It works for what I need to do, and is my daily duty tool.
 
Agreeing with the above posters that using partitions is your discretion and there is no right or wrong. The thing that makes me cringe however is you backing up to a single physical device. If that drive fails, you lose all partitions and data. Partitioning will not save you from a drive failure if all partitions are on the same physical drive as chown33 pointed out above

I myself do a tiered backup approach. An external drive holds computer backups. Whatever fits on Blu-Ray optical gets burned as a second archived backup and whatever doesn't fit gets archived onto a second hard drive. Using a cloud data backup service also works.

Optical still has a place for me since encrypting ransomware is useless against an already burned disc.
 
Hmm... One of my drives has partitions for each bootable installer from Leopard to Mojave, so 10 partitions there.
partition with archived installs for a lot of apps and utilities, which has all OS X/macOS installer apps and ISOs from Tiger to Mojave, including combo updaters for all Mac systems back to 10.2.8 (Jaguar), plus Windows installer ISOs for Win8 and three different "generations" of Win10 ISOs (plus backups of different versions of Boot Camp support files). Oh, there's also MS Office updates going back to the original OfficeX. Lotsa stuff on that one partition.
Plus 5 other partitions, mostly used for random backups for service work.
Oh, and three old full bootable backups of my main Mac, with 10.8.5, 10.10.5, and 10.12.6 - all with basically the same other software and old files relevant to that particular version.
So, 20 partitions on one 1TB spinner. Most of the partitions are less than 8GB in size.
It works for what I need to do, and is my daily duty tool.

Agreed.

I call it my tech drive, and it is an external. 5 or 6 bootable partitions with tools, plus one big partition for storage, installers, etc. Been doing it for more than a decade...on an 512 SSD these days.

But I would not recommend this for daily use, or regular computing. Too easy to fill small partitions; adding limitations with no real benefit (setting aside bootcamp, etc.) for normal user.
 
I am not a "normal" user. I run a part-time (my hobby) Mac repair shop, and occasionally see just about anything made in the last 20 years (worked on a Mac Quadra 605 a couple of months ago) Got a box of old installer CDs (and some floppy disk installers, not used those in a long time, 12 or 15 years...)

SO my "tech" drive has a bunch of small partitions, but those are mostly dedicated to the bootable macOS installers, so just enough space to have the installer on each partition. Those partitions don't change, just the installer. Each installer partition is customized, leaving about 50 MB free space on any installer partition, so every partition is a different size, nothing else will fit with only 50 MB space free!
TOTAL space used by the 10 bootable installer partitions is less than 60GB. The other partitions tend to be a 150-200 GB. Many users don't ever store a lot on their main drive, regardless of the capacity of the drive, and a few medium size partitions are very useful for transfers, etc. When I run into the occasional "big user", my 2TB drive, one partition, plugs right in... :cool:
 
You can make a disk-image for each backed-up computer, and then mount it while doing the backup. All those disk-images can reside on a single partition. Use sparsebundle or sparseimage format if desired.

You should then make backups of those disk-images, otherwise a single point of failure (the big HDD) will wipe out all the backups for all the computers.

What worries me about disk images is that I heard:
1)They get corrupted
2)only macs can unmount them
3)Mounting and unmounting 200GB disk image might strain the CPU and HDD
4) I dont think they are bootable
 
What worries me about disk images is that I heard:
1)They get corrupted
2)only macs can unmount them
3)Mounting and unmounting 200GB disk image might strain the CPU and HDD
4) I dont think they are bootable
1) No more so than disk partitions. Treat them the same way.

2) You haven't stated so far that anything other than Macs were being backed up.

3) Shouldn't be any strain at all. Make the disk-image a sparsebundle, and it should be fine.

4) They aren't, but they can easily be cloned to a bootable disk, using an app like Carbon Copy Cloner, or Disk Utility's "Restore" action.


If non-Macs are really part of the mix, and the disk partitions really need to be bootable on those non-Macs, then you should be certain that a partitioned GPT disk will be bootable for those computers.
 
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What worries me about disk images is that I heard:
1)They get corrupted
2)only macs can unmount them
3)Mounting and unmounting 200GB disk image might strain the CPU and HDD
4) I dont think they are bootable
1) anything can get corrupted. Especially politians.
2) a 1 year old can unmount. See #1
3) running all cores at 100% may strain a cpu slightly. Basically, I think #3 is a complete non issue.
4) debatable.

I have Windows partitions as a file on my iMac using parallels. I used to have an actual windows partition. With the speed of these new computers, I can’t perseive an actual speed difference. But the file route is much easier the manage and use.
 
But , apparently, not all disks slow down as the disk fills. Assuming no fragmentation. Even so, the speed difference probably isn’t a issue.
 
there are few reasons to partition a large hard drive

I use Carbon Copy Cloner to backup my relatively small boot drive. I use 2 different partitions on an external drive to back up on alternating days. Obviously if I lose the drive I lose both backups, but I have others including multiple unreliable Time Machine backups. I'm actually running my system right now from one of these cloned partitions as I am running Techtool Pro on my boot drive to try to diagnose some bridgeos kernel panics (210 errors).
 
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I use Carbon Copy Cloner to backup my relatively small boot drive. I use 2 different partitions on an external drive to back up on alternating days. Obviously if I lose the drive I lose both backups, but I have others including multiple unreliable Time Machine backups. I'm actually running my system right now from one of these cloned partitions as I am running Techtool Pro on my boot drive to try to diagnose some bridgeos kernel panics (210 errors).

Great example of uses for multiple partitions. Full boot systems (clones or otherwise) are the best, most compelling reason IMHO.

BTW...panics are often caused by RAM. If it is an older Mac, consider pulling one stick at a time to find the culprit. If you have done a recent RAM upgrade...might be the culprit. Kernel extensions are the next best place to look too.
 
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