Questions about Encryption between OS's

Discussion in 'Mac Basics and Help' started by Texas_Toast, Jul 21, 2019.

  1. Texas_Toast macrumors 6502a

    Texas_Toast

    Joined:
    Feb 6, 2016
    Location:
    Texas
    #1
    I have two MacBook Pros - one with Mountain Lion and one with Sierra.

    And on a regular basis, I run CCC and clone each laptop to a separate HDD.

    Because the name of each drive reflects the computer and the date (e.g. Retina_2019-07-21), I have a need to update the drive name before each clone.

    In Sierra, I just go to Disk Utilities, right-click on the drive, and update it from say "Retina_2019-06-15" to "Retina_2019-07-21".

    In Mountain Lion, this is not possible when FileVault is turned on. However in an earlier thread someone showed me that you can go into Finder and simply rename the drive there. Of course the downside to this approach is that in Disk Utilities you then have two names. For example, it appears that the physical drive retains it's original name (e.g. "MBP_2019-04-01") but that there is a new logical drive called the enwer name (e.g. "MBP_2019-04-30") So the only way to get the Mountain Lion drive's name updated would be to DE-crypt the entire HDD, then rename it in Mountain Lion Disk Utilities, and then RE-encrypt it - which could take days to do?!

    I am looking for a better approach to this!

    So on to my questions...

    1.) Will I break anything if I encrypt an external HDD using Mountain Lion and then I try to unlock it while it is plugged into Sierra?

    2.) Can I take an external HDD encrypted in Mountain Lion and decrypt/re-eencrypt it in Sierra?

    3.) If I take an external HDD encrypted using Mountain Lion, plug it into my laptop running Sierra, unlock it in Sierra, and then change the drive name using Sierra's Disk Utility, what will happen when I plug it back into my laptop running Mountain Lion?

    To summarize, it seems pretty easy to take an external FileVault HDD and rename it using Sierra's Disk Utility, but I don't want to FUBAR the encryption on that Mountain Lion drive!!

    I gues I do not understand how FileVault and encryption work on my old laptop running Mountain Lion and then on my newer Retina running Sierra... :confused::confused::confused:

    Someday I will get my old MacBook updated to a more modern OS, but there is still software that I use on a weekly basic that will NOT run on my Retina with Sieera, so I keep nursing my old Mountain Lion laptop along until I can get things working on a newer machine.

    Hope my questions and concerns make some sense?!
     
  2. NoBoMac Moderator

    NoBoMac

    Staff Member

    Joined:
    Jul 1, 2014
    #2
    Not sure what you are trying to do here: are you trying to rename the drive in the Mac or the external drives?

    If external, can simply rename the volume on desktop or Finder, as an encrypted volume is basically two-tiered in Disk Utility. There will be the physical drive name (eg. "Toshiba Big Honking In Size"), and then the unlocked volume name (which can rename with no issue). I've done this across all version of Mac since Lion: make a clone and then rename the clone volume to be a date.

    If trying to rename the internal drive, I would not do it. Not buying anything, maybe can break something.
     
  3. Texas_Toast, Jul 22, 2019
    Last edited: Jul 22, 2019

    Texas_Toast thread starter macrumors 6502a

    Texas_Toast

    Joined:
    Feb 6, 2016
    Location:
    Texas
    #3
    My external HDD is named after the backup (e.g. MacBook_2019-07-22). That way, there is never any ambiguity what a backup clone consists of.

    On my Retina with Sierra, before I do a new backup, I simply go into Disk Utility and rename my external drive accordingly. But on my old MacBook running Mountain Lion, this option isn't available. And the only way I can truly do that, is to decrypt the external drive, then use Disk Utility to rename the drive, and then re-endcrypt the drive. That is a major pain in the ass and could take several days to decrypt/re-encrypt.

    A few months ago someone pointed out I could name the external drive in Mountain Lion using Finder, which works somewhate, but the problem is that in Disk Utility the drive retains it original name (volume??) and only the logical drive gets renamed. So in this scenario, when I go into Mountain Lion's Disk Utility, I see my external drive labeled as MacBook_2019-04-15 and MacBook_2019-07-22 which is somewhate confusing.

    Make sense?


    Yes, and on my Retina with Sierra that is how it works. The exteral physical drive is named "ASMT 2115 media" and the logical drive is "Retina_2019-07-01".

    But as described above, on my old MacBook running Mountain Lion, the physical drive is named the last time I partitioned it (e.g. "MacBook_2019-04-15") and then there is the logical drive which is currently "MacBook_2019-04-15" and when I rename it in Finder it changes to "MacBook_2019-07-22"" but they physical drive is still named "MacBook_2019-04-15".

    I'm being picky, but still...

    To further test things, I plugged the external Mountain Lion backup into my Retina, and in my Retina's Disk Utility the physical drive is labeled "ASMT 2115 media" and the logical drive is "MacBook_2019-04-15".

    Not sure why there is a descrepency between how Lountain Lion and Sierra show things?

    At any rate, my main question was whether renaming the logical drive in Sierra would break the File Vault encrytion when I run CCC oin Mountain Lion...

    However, since it appears that the physical drive name is the old backup date in Mountain Lion, I guess I might as well just change the logical drive name in Mountain Lion's Finder and live with the descrepency?!
     
  4. chown33 Moderator

    Staff Member

    Joined:
    Aug 9, 2009
    Location:
    bedlam
    #4
    I would name the "physical drive" something that would make sense regardless of backup dates, like "MacBook_backup" or "Retina_backup" or whatever.

    Then rename the encrypted volume contained therein using the date, like "Macbook_2019-07-20".
     
  5. Texas_Toast thread starter macrumors 6502a

    Texas_Toast

    Joined:
    Feb 6, 2016
    Location:
    Texas
    #5
    Yep, I came to that same conclsuion as I was decrypting this backup drive over the last 8 hours!
     
  6. satcomer macrumors 603

    satcomer

    Joined:
    Feb 19, 2008
    Location:
    The Finger Lakes Region
    #6
    With externals I would be more considered about physical theirs! Maybe a locking the drive down so it can’t be stolen, especially in college, don’t ask!
     
  7. Texas_Toast thread starter macrumors 6502a

    Texas_Toast

    Joined:
    Feb 6, 2016
    Location:
    Texas
    #7
    I tried your suggestion, but it ultimately did NOT work.

    How so?

    I spent 8 hours decrypting my backup drive in Mountain Lion. Named the physical drive something like "HGST 1 TB" and then named the logical drive "MacBook_2019-07-25". So far so good.

    However, once I re-encrypted the drive in Disk Utility both the physical drive and the logical drive show "MacBook-2019-07-25". (I wondered why I would name the physical drive after a specific backup?!)

    So apparently this is a quirk in how Mountain Lionw orks, because this same scenario in Sierra doesn't happen.

    Guess it is just another reason that I need to upgrade my old MacBook some day... :(
     
  8. chown33, Jul 26, 2019
    Last edited: Jul 26, 2019

    chown33 Moderator

    Staff Member

    Joined:
    Aug 9, 2009
    Location:
    bedlam
    #8
    Try this.

    1. Completely erase the "MacBook" backup disk. Encryption disabled. 1 partition.
    You may need to disable encryption first (I've forgotten since the last time I played with this).

    2. Name the disk "MacBook_backups".

    3. Enable encryption.

    4. Let it finish encrypting the disk.

    5. Rename the volume "MacBook_some-date-here" in Finder.

    6. With nothing else copied to the disk, look at it in Disk Utility, and see what the names are for the "physical" and "logical" drives.
    If they're what you want (physical "_backup" and logical "_date"), then proceed to make the CCC copy of your MacBook, and name the target volume in Finder.

    7. For completeness, after the copy is made, I'd look again in DU that the names are what you want.


    I think the rule is "Rename to match" at the time encryption is enabled, but after it's been enabled, the "physical" disk won't be renamed unless you decrypt and re-encrypt (per your description). Again, I've forgotten exactly how it worked when I last played with this, but I do remember the phys-name being "sticky" from the point encryption is enabled.

    I'd probably experiment with the sequence of naming, enabling encryption, etc. using a smallish thumb drive, or maybe even a disk image of a GB or so. A sparse bundle should be fairly fast to change, but adhere to the same rule that a larger disk would.
     
  9. NoBoMac Moderator

    NoBoMac

    Staff Member

    Joined:
    Jul 1, 2014
    #9
    No need to disable encryption to erase, as reformat will wipe the encryption key, leaving one with a disk full of blocks of gibberish.

    And turning on encryption should go almost instantly, as no data on the drive to encrypt (will encrypt blocks when data written to said blocks).
     
  10. Texas_Toast thread starter macrumors 6502a

    Texas_Toast

    Joined:
    Feb 6, 2016
    Location:
    Texas
    #10
    @chown33,

    Thanks for the tips above. Sounds like a good strategy.

    Fortuately I have several hard-drives for backups, so I can easily try this out on another backup drive. However, I'm a bit burned out on this right now, so when I do another backup in a few weeks, I will try out your instructions above and report back with my findings. :)

    Thanks in advance!
     

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9 July 21, 2019