Managing mounting CoreStorage volumes

[0004838]

Two issues that are making using CoreStorage HFS+ Encrypted volumes a little troublesome:

1) There doesn't seem to be any way of preventing the unlock prompt for an encrypted partition when plugging in a drive. I've tried using FSTAB but, despite having read somewhere that this should work, it doesn't—at least, not for me. Is there a solution for this?

2) I'm being prompted to unlock volumes that have already mounted themselves using the password stored in Keychain Access. How can I fix this?

Cheers.

 

[Weaselboy]

I use a couple encrypted volumes and never have either of these issues. I would eject and detach both drives then open Keychain and find the saved password for each drive and delete the Keychain entry (making sure you know the passwords first). Then attach each drive and you should get a popup asking for the password. In that popup is a checkmark to remember the password in Keychain. So either the password and check the box then apply and you should not be prompted for the password again.

 

[0004838]

Re: 2) Yeah, I figured that might be the necessary thing to do. I hoped there might be a less cumbersome way, akin to the CLI command for resetting the Spotlight index to prevent duplicates in the Open With… list.

As for 1): I'm not sure what you mean by never having this issue. Perhaps you didn't understand what I meant? Not everyone is aware of FSTAB.

Cheers.

 

[Weaselboy]

As for 1): I'm not sure what you mean by never having this issue. Perhaps you didn't understand what I meant? Not everyone is aware of FSTAB.

I do understand what FSTAB is, but maybe I'm not clear what you are trying to do? It sounded like you wanted to the drive to mount and unlock on its own without seeing the password box. Is that not what you want?

 

[0004838]

I do understand what FSTAB is, but maybe I'm not clear what you are trying to do? It sounded like you wanted to the drive to mount and unlock on its own without seeing the password box. Is that not what you want?

On reading back, I realise I should have been clearer initially.

I use encrypted volumes extensively, and some of my drives have three or four encrypted partitions, several of which I only mount occasionally. I've refrained from storing the passwords in the Keychain for those particular partitions, but OS X still attempts to mount them and will always prompt for the password.

I'd like to selectively prevent OS X from attempting to mount those partitions when the drive is plugged in, and thereby avoid a flurry of unlock prompts that I have to "escape" through before I can get on with what I'm doing.

I did once read that FSTAB could be used to accomplish this, but I've tried UUIDs and Labels and neither of those seems to work with CoreStorage volumes.

So, is there a way of preventing OS X from auto-mounting these encrypted partitions?

 

[Weaselboy]

Ahh.... I gotcha.

Yeah, from what I understand FSTAB should be able to do that, but I have never done so myself. Are the instructions here any help?

I did this command on my encrypted external drive called Backup and got the UUID info.

diskutil info /Volumes/Backup

I'm thinking you would want to use the UUID of the encrypted logical volume (LV UUID). Is that what you tried?

This disk is a Core Storage Logical Volume (LV).  Core Storage Information:
   LV UUID:                  91B1A663-11CC-464A-834F-852D07D4A45D
   LVF UUID:                 1B42AB6D-58D6-4F6E-9BA1-E855C8215DF4
   LVG UUID:                 1FD07DD0-D555-44E2-AC0E-9273F52162FF
   Fusion Drive:             No
   Encrypted:                Yes

 

[chown33]

I use encrypted volumes extensively, and some of my drives have three or four encrypted partitions, several of which I only mount occasionally. I've refrained from storing the passwords in the Keychain for those particular partitions, but OS X still attempts to mount them and will always prompt for the password.

I'd use disk images instead of actual partitions, for precisely the reasons described.

I think a sparse bundle will give the best economy of disk space, and its bands are conducive to incremental backup.

If you ever want a disk image to mount at login, you simply add it to your Login Items.

 

[0004838]

Ahh.... I gotcha.

Yeah, from what I understand FSTAB should be able to do that, but I have never done so myself. Are the instructions here any help?

No, I'm already familiar with FSTAB, but thanks.

I did this command on my encrypted external drive called Backup and got the UUID info.

diskutil info /Volumes/Backup

I'm thinking you would want to use the UUID of the encrypted logical volume (LV UUID). Is that what you tried?

This disk is a Core Storage Logical Volume (LV).  Core Storage Information:
   LV UUID:                  91B1A663-11CC-464A-834F-852D07D4A45D
   LVF UUID:                 1B42AB6D-58D6-4F6E-9BA1-E855C8215DF4
   LVG UUID:                 1FD07DD0-D555-44E2-AC0E-9273F52162FF
   Fusion Drive:             No
   Encrypted:                Yes

I tried both the LV UUID and the Volume UUID (on OS X 10.9.5, diskutil info /volumes/foo offers the Volume UUID, diskutil cs info /volumes/foo offers the Logical Volume UUIDs which you list). No success with either.

I'd use disk images instead of actual partitions, for precisely the reasons described.

I think a sparse bundle will give the best economy of disk space, and its bands are conducive to incremental backup.

If you ever want a disk image to mount at login, you simply add it to your Login Items.

This is certainly something to consider, as it doesn't look as though Apple have offered a mechanism to do what I want to achieve. I'll put it on the back-burner for the time-being, as it'd involve quite a bit of data transfer to achieve safely.

Thanks to both of you for the input

 

[0004838]

I would eject and detach both drives then open Keychain and find the saved password for each drive and delete the Keychain entry (making sure you know the passwords first).

So, I tried this, and believe it or not the same thing keeps happening. I think there's a fundamental issue with these Core Storage prompts on my Mac, because I think it does it with almost every Core Storage volume I attach.

I'll try some troubleshooting to see if I can narrow down the cause…

 

[Fishrrman]

Opinion:

What the Mac OS needs is a good, standalone, graphically-designed utility that allows the user to create/manage/delete CORE storage volumes and fusion drives.

Disk Utility IS NOT "enough".

Name it "Fusion Drive Tools" for lack of a better moniker.

Somebody ought to be able to do this.

(end opinion)

 

[0004838]

Opinion:

What the Mac OS needs is a good, standalone, graphically-designed utility that allows the user to create/manage/delete CORE storage volumes and fusion drives.

Disk Utility IS NOT "enough".

Name it "Fusion Drive Tools" for lack of a better moniker.

Somebody ought to be able to do this.

(end opinion)

With the advent of AFPS in macOS Sierra, Apple will already be re-designing the Disk Utility app, so perhaps they'll produce something that meets our requirements then… Having said that, I'd still be happy even if it was CLI only, so long as the functionality was there.