Suggestions for Formatting/Partitioning External 4TB Drive

Discussion in 'Mac Basics and Help' started by CrashX, Jun 21, 2017.

  1. CrashX macrumors 6502

    Apr 13, 2012
    I just bought a 4TB external hard drive. Why? A 4TB Seagate Backup Plus was on sale for $100.

    First - should I just send it back? I don't think I'll EVER wrap my head around storing 4TB on a single drive, other than as a backup of backups? If it were to fail and it was the ONLY drive I had holding 4TB of data? Geezus...

    If the gurus think it's cool and I can actually TRUST a 4TB drive - then what formatting and/or partitioning should I use?

    If the drive fails, do all partitions fail - or how exactly does that work?

    Thanks for any info. I already have a dedicated Time Machine backup drive, but it's "only" 1TB. And I have run into a problem in the past with Mac OS "fussing" at me because the drive SHOULD (?) be 2TB for my 500GB SSD?

    So do I just create a 2TB partition just for Time Machine with this new drive and then reformat the old external drive for other purposes? Then possibly 2TB of ExFat for holding movies, audio, stuff like that?

    Thanks for any advice - particularly as to whether, if the drive fails, if all partitions fail? And whether I should use ExFat rather than HFS, given Apple is about to ditch HFS anyway?
  2. MC6800 macrumors 6502

    Jun 29, 2016
    I would keep it one 4TB partition, and use it as a second Time Machine backup and general archiving. Always good to have at least two backup drives. Also, 4TB may seem too large to you today, but rest assured it'll eventually look puny. I find it's easier to expand the TM by removing other non-TM files-- otherwise you end up creating a series of ever-larger partitions.

    Drives fail in all sorts of ways, though a whole-drive failure is common.

    You should stick with HFS for now.
  3. CrashX thread starter macrumors 6502

    Apr 13, 2012
    Thanks. I'll do that then.

    I knew I could store other files on a Time Machine backup drive - but didn't know if it was a good practice?
  4. MC6800 macrumors 6502

    Jun 29, 2016
    It has worked fine for me for years. One caution though is to not add stuff during a backup session if the drive is near full. The reason is that TM checks how much room is available on the drive when it starts a backup in order to calculate how much old TM stuff to clear out of the way, and reducing the space after the calculation would throw it off-- it gives you an error.
  5. 0002378 Suspended


    May 28, 2017
    I would create multiple partitions for a very simple reason. Sometimes, an entire partition can get corrupted during file transfer or improper ejection. If that happens, you don't want to have to reformat the whole thing.

    Of course, if your hardware itself fails, extra partitions won't save you, but they will in the aforementioned case.

    As for how to distribute across partitions in terms of size/data, that's a great question and really depends on your usage. Partitions can be resized any time you want, so if your data grows, you can extend a partition or shrink another.

    To give you an example, I created one partition for all my frequently accessed media (movies/music/pictures), and one "archive" partition for very old data (like documents created in my college days, old programming assignments) that is not accessed frequently.

    It might be wise to have redundant copies of all your important/critical documents (personal/sensitive data you cannot live without), ... password protect them in a disk image (.dmg file), put one copy on each partition, so that if one partition fails, the other will have your copy.

    Since you have a ton of space, you could have entire redundant partitions - partitions that are exact copies of each other or as you put it, "backups of backups". Why not ? Make use of that space.
  6. CrashX thread starter macrumors 6502

    Apr 13, 2012
    Many thanks! I decided to go with 2 partitions - one "dedicated" for Time Machine, the other as a way to store my personal collection of movies, music, and photos.

    I hope this works to my advantage when Apple introduces the iOS system to our Macs - that way I can keep HFS on my "fun" backup, and - after upgrading to Sierra Stoned and giving her a test drive for a months or so, reformatting the Time Machine partition to the new freshness and keep on rollin'.

    And once this is all done, I'll reformat my former Time Machine 1GB drive to Fat and see if the PS3 will power her up or not. If not, I'll give ExFAT a shot and see if it agrees with my PS4.

    Greatly appreciate all of the advice!
  7. iRock1 macrumors 6502a


    Apr 23, 2011
    2 TB of backup for a 500 GB disk seems like an overkill to me. I'd split your extermal disk in one partition of 1 TB for another Time Machine backup apart from the one you already have, and another partition of 3 TB for media. (And yes, I know it seems a lot at first, but considering how video is gaining in quality and therefore in size over the years, it won't pass a lot of time until you realize you need more space.)

    Also, consider getting another external disk for a copy of your media. Otherwise it will be only in one place and we all know what that means.
  8. HDFan macrumors 6502a

    Jun 30, 2007
    If this means that your only backup will be the Time Machine partition on the 4 TB drive that's not a good idea. Even if the hardware doesn't fail, TM backups can get corrupted. You need to have at least 3 backups of the data that you don't want to lose, on 3 different media types (hd, cloud, tape [or 2 different drive types from different manufacturers]) in at least 2 different locations, at least one off-site.
  9. vkd macrumors 6502a


    Sep 10, 2012
    Yes, you are right, not good practice. Better to leave a Time Machine drive for TM to manage solely. If you start using it for common storage too you could soon find it getting its knickers in a twist.
    --- Post Merged, Jun 23, 2017 ---
    Are you absolutely sure you "need" "at least 3 backups of data"?
  10. HDFan macrumors 6502a

    Jun 30, 2007
    Depends upon your risk tolerance. Some things you might not need such redundancy (letters written 5 years ago), and others would be disastrous if lost (pictures taken of the kid's first ice cream).

    My post was based upon an article written by Larry Jordan (which I can't find now) and my experiences with trying to do a restore only to discover that my TM backup was corrupt.

    There are variations, but here is BackBlaze's take:
  11. vkd macrumors 6502a


    Sep 10, 2012
    OK but that article although it mentions 3 copies, only advises 2 backups. The third copy is the original.
  12. dwig macrumors 6502

    Jan 4, 2015
    Key West FL
    Risk tolerance is the key to deciding on a backup strategy.

    I work for a professional art photographer and do all of his image processing and most of the printing. I have 11tb primary storage, 1tb internal plus 2 external 5tb drives. I have an additional 5tb external drive to TimeMachine. Monthly, around the middle of the month, the internal 1tb is cloned to create a bootable volume on another external drive that holds 3 such partitions. The two 5tb externals (not the 3rd TM external) are backed up at the end of each month to another set of externals that are kept off site. There are two such offsite backup sets, each being used every other month. Since we don't keep mission critical business & images files on the internal we don't bother with keeping its backup offsite. There is another 2tb that backs up the digital camera cards bringing the total storage that I use at 38tb, not counting the internal drives in the two print servers and their backups.

    All told, this gives me 3 backups of my primary images files (TM + last month's offsite + 2 month old offsite) and an additional 4th backup of the photographer's original camera images (these live on one of the work drives as well). The photographer has his copies of the camera images along with 2 backups, so these precious jewels existing in 7 places.

Share This Page