Creating an Encrypted Disk Image on an External (USB) Drive

I have an external 600 GB drive (2x 300 GB SATA 3.5" disks in a Thecus N2050 RAID0 external enclosure connected to iMac by USB2) onto which I would like to backup a large amount of data (500 GB).
I store this external drive away from my home (in the office) and since I cannot guarantee physically locking away the drive I would like to logically lock the drive by placing all the backup data into an encrypted disk image created on that volume.
I have tried creating an encrypted disk image on my USB volume in Disk Utility (Apple's instructions here) but I experience a number of issues not documented in the Apple article:
1) I am not presented with a drop-down option for the size of the disk image.
2) When I go ahead and try to creat the image I am told that the creation was impossible "file or folder does not exist".
Is it possible to create disk images on USB volumes (I cannot create such a large disk image on my iMac HDD as I do not have sufficient space).
thanks in advance
Raf

I realised that in Disk Utility you must not have any of your mounted drives highlighted in the left hand pane.

Similar Messages

Backing up to encrypted disk image on an external usb drive

I'd like to use an encrypted disk image on an external USB drive as the target for my Time Machine backups, but it seems that Time Machine will only recognize physical external drives, and not mounted disk images in the "Change Disk..." window.
Is it possible to make Time Machine use disk images mounted from an external USB drive?
Thanks.

..."Is it possible to make Time Machine use disk images mounted from an external USB drive?"...
Actually, with a few caveats, it is possible.
Just follow one of the many tutorials on the web for creating an encrypted sparse bundle for use with "TimeMachine" on a network volume (i.e. MACaddress.sparsebundle naming convention, password stored to the system keychain, etc.), and then attach the drive locally and select the drive (not the mounted disk image) as the backup drive. As "Glen Carter" reported in another thread on this site, "TimeMachine" is smart enough to know to mount the disk image for backups when the drive is connected locally.
There are caveats for example, - while backups remain automatic, it appears that actually browsing the backups requires that the disk image be mounted manually first, then accessed via the "Browse Other Time Machine Disks…" option.
One caveat to pay particular attention to is what happens when the drive starts to fill up and space becomes limiting - the processes of deleting expired backups and sparse image compaction may not be well integrated, as discussed here:
http://www.flokru.org/2008/03/15/time-machine-backups-on-network-shares-2-possib le-problems/
The article implies that the end result could be deletion of all backups! The article is dated March 2008 but I have no idea whether the issue has been resolved.
Just be advised that it is an unsupported configuration so the extra security will come at the cost of some convenience and potential increase in the chance of data loss. Most users recommend using supplemental backup strategies since the intended purpose of TimeMachine is actually very limited and often misunderstood. Apart from that, it is a rule written in stone that whenever encryption is used, the encrypted items themselves must be backed up.

Unable to create an encrypted disk image in Lion

disk utility gives the error Unable to create "Volume.dmg." (error - 60008) when creating an encrypted disk image. I am using the following steps:
    1.    Open disk utility
    2.    Select the disk (internal or external) to create the image on
    3.    Select File>New>Blank Disk Image…
    4.    Save As: 'Volume'
    5.    Name: Volume
    6.    Size: 50GB
    7.    Format: Mac OS Extended (Journaled)
    8.    Encryption: 128-bit AES encryption
    9.    Image Format: read/write disk image
    10.    Click the Create button
    11.    Password dialog appears
    12.    When I enter a password the dialog closes after entering only a few characters i.e. before I've finished typing, and the following error message displays:
Unable to create "Volume.dmg." (error - 60008)
I have previously, successfully, created encrypted disk images in Snow Leopard, and I don't know why I can't in Lion
Does anyone have any ideas?

Thanks for this Thomas.
I've tried naming the image differently, but still received the error, I did however try different permutations for the password.
The error seems to happen if I use a purely numerical password string and occurs on input of the 10th numerical character, if I start with numerical character but use an alpha before the 9th number I can continue and create a password, and I can create a password if I start with an alpha and switch to numerals after the first alpha character, purely alphabetical passwords are fine too.
It seems that Lion doesn't like purely numerical passwords greater than 9 characters, whereas Snow Leopard wasn't so fussy. Seems it's a bit of a bug.
Thanks for your help

Unable to create an encrypted disk image with Disk Utility

Hi:
With our upgrade to Lion a few weeks ago, we're now unable to create an encrypted disk image of any type using Disk Utility any more. This problem occurs on 3 different machines, and is reproducible whether one is using an internal HD or an external FW HD. We can successfully create nonencrypted disk images.
This is a duplicate post with all the details here: https://discussions.apple.com/message/18469359#18469359
We haven't had any luck with a solution trying various permissions fixes as helpfully suggested by other readers in response to the error message # (-60008 error), so I'm hoping that someone else has run across a solution from the encrypted disk image perspective and that this tag line will generate some help.
Thank you!

Save As: 01 (on Desktop)
Name: 01
Size: 100 MB
Format: Mac OS Encrypted (Journaled)
Encryption: 256-bit AES
Partitions: Single partition- Apple Partition Map
Image Format: read/write disk image
At the password window that pops up I enter: 1234567890
This says password strength is "Weak"
All works fine
Then I repeated this using:
Save As: 02 (on Desktop)
Name: 02
Size: 100 MB
Format: Mac OS Encypted (Journaled)
Encryption: 256-bit AES
Partitions: Single partition- Apple Partition Map
Image Format: read/write disk image
At the password window that pops up I enter: 1234567890 and when I start to enter the next "1" I get the "Unable to create "02.dmg." (error -60008)
OS 10.7.4
Disk Utility Version 12.1.1 (353)

R&R Backup (Image) on two external USB drives

Hi Forum,
in the early BIOS state of my T500 and working with Vista I had to rebuild my system several times due to OS failures. For that reason I periodically run R&R and make images on an external USB drive.
Since I'm traveling very much I always have the USB drive with the image with me. The drive contains one basic backup and some incremental backups up to level 25 (at the time being).
Now my goal: in case of a theft or a failure of that USB drive, I want to keep a second image on another USB drive at home.
Now my questions:
1: Is it possible to make backups with R&R (basic and incremental) of one computer on several USB drives?
In that case R&R must detect which incremental level is present on the USB drive and create the appropriate backup (management of the levels on the USB drive, not on the computer).
Example: USB drive A contains one basic backup and some incremental backups to level 12 (consistent) - USB drive B contains one basic backup and some incremental backups to level 17 (consistent as well).
2: If the answer to question 1 is "yes" - does R&R manage this automatically in the windows interface or is it necessary to use the DOS level (rrcmd.exe). Which switches are to be set?
Many thanks for help
Axel

It is a difficult question: the help file isn't entirely clear.
Here is my recent experience: using R&R 4.21 I had backed up my machine to the internal drive + 1 external USB drive several times, so that there was the base back-up and several incrementals on both drives. I also had copied the base backup + earlier incrementals to DVDs using the advanced menu entry for that task, just to be on the safe side. And, using another program (the free version of Syncback by 2BrightSparks), I regularly duplicate documents + pictures to the USB drive, so I'm covered in 3 different ways on 2 types of external hardware.
On one or two occasions I did an incremental backup on the internal drive only--but the next time I did an incremental with the external USB drive attached, the missed incrementals were synchronized onto the external drive.
Now, 2 weeeks ago I decided to zap the main disk and rebuilt the OS + programs to have a "clean slate" for 2010. When I had finished reinstalling everything minus personal files, I made a base backup (the only choice offered) on the internal drive with the external drive attached. This effectively erased the existing earlier backups on the external drive and copied over the new base backup.
So this synchronization only operates in one direction: the external USB drive's store of R&R backups is a replica of what is on the main internal drive.
I strongly suggest trying this all out (i.e. missing an incremental backup on the external drive, then making sure it has catched up after the next incremental backup) after making an external copy on DVD of the R&R backups. In fact, if you have the nerve, the patience and the time (and the DVD backups!), you should also try a bare metal restore of the DVD backup (I did last year when I bought this machine and hadn't too many personal files on it-- R&R 4.21 does actually work!)
sorry i can't be more specific, but my advice is to practice the "disaster recovery" at least once, early on, in order to be sure how it works if disaster does strike.

How to recover after performing an 'Erase' and then 'Partition' within Disk Utility of an External USB drive?

Hi - I accidently ran an 'Erase' and then 'Partition' within Disk Utility of an External USB drive (meant to run it against another drive that was plugged in). Does anyone have any suggestions on if it is possible to recover from this? It has all my family photos on it and my backup is a few months old :-(
I tried running Stellar Phoenix Mac Data Recovery but it found what looks like basic mac folder structure (probably from the first erase). I think what messed me up was that I rain the repartition which formats the drive a 2nd time! Any help is truly appreciated!
thank you,
-Steve

Hello RalphR_MI,
Take a look at this page, which lists several articles. Please let me know if any of these help you restore your backup.
Also, take a look at this article, as well as this one.
I hope this helps. I'm not sure of a few things, so I'm sorry for sending you so much, but I'm confident it will give you something new to try.
Please let me know if this helps. Good luck!
↙-----------How do I give Kudos?| How do I mark a post as Solved? ----------------↓

Problems creating a disk image on an external hard drive

Hiya,
I've been trying to create a disk image on my dad's external hard drive to hold my back-ups all day with no luck. I've managed small ones, e.g. a few MB, but when trying to create images 20 or 40 GB in size (which is what I need), it isn't working.
When I've tried creating them in Disk Utility with the place to save them to as the external HD, it says "Unable to create... Illegal seek" which doesn't explain much to me! I have been successful in creating a large disk image on my own HD, but when I try to move it to the external HD, it says "Sorry the operation could not be completed because an unexpected error occured (Error code -1309)."
Extra info:
- I am saving my back-ups in a disk image, as they must be password protected, so that's why I'm not just copying them over.
- There's plenty of space avaliable on the external HD, so it would seem that isn't the problem.
- The HD is a Freecom Classic SL, connected via USB cable.
Any ideas anyone?
Thanks alot,
Charity

Found the answer. It was formatted for Windows.

Disk Utility Not Formatting External USB Drive

Hello,
I recently upgraded to Leopard.  Around this same time, my company purchased two, 1 Terabyte USB External drives for my coworker and I in the graphics/web development department.  They arrived this morning and we were very excited.
My problem is that I cannot get Disk Utility to erase/format the new, external USB TB drive for use with my MBP.  Disk Utility fails almost immediately with the following message:
"*Disk Erase Failed*
Disk Erase failed with the error:
File system formatter failed."
The options I'm choosing for the Erase are:
Volume Format: MAC OS EXTENDED  (i've even tried the 'journaled' version too)
Name: TB
As soon as I hit 'Erase' I get the error message I listed above.  The volume never mounts on my desktop and does not exist.  I can see the drive itself in the System Profiler, so my Mac sees it, it just can't format it!  I've also made sure all my permissions were repaired, so I'm just a little confused as to why this simple task keeps failing?
Is there some additional, esoteric step that I'm missing?
My coworker was able to get his disk to work because he did NOT have Time Machine turned on yet.  When he connected his new TB drive, Time Machine asked him to format/initialize the disk and he of course said "ok."  I had Time Machine set to use my OLD external USB drive and it's been working great. As of this writing, my coworker is a happy camper. I, however, am not.  I'm not blaming Time Machine, just noting the differences between my coworker's experience and my own. Since the volume is not currently mounted on my machine, I can't format my disk the same way as my coworker has done using Time Machine, since Time Machine doesn't see the volume.
My fear is that the manufacturer (whom I've also contacted and am awaiting their response) will throw this back to a software problem....and the folks on the forum here will point their fingers and say 'hardware problem.'  Ah, the eternal struggle.....who to blame?
Any help or additional troubleshooting tips are greatly appreciated.

This is the best, and only, way to format an external hard drive, which is courtesy of Kappy.
Extended Hard Drive Preparation
1. Open Disk Utility in your Utilities folder. If you need to reformat your startup volume, then you must boot from your OS X Installer Disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger or Leopard.)
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Click on the Options button, set the partition scheme to GUID (only required for Intel Macs) then click on the OK button. Set the number of partitions from the dropdown menu (use 1 partition unless you wish to make more.) Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the volume(s) mount on the Desktop.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process will take 30 minutes to an hour or more depending upon the drive size.
Steps 4-6 are optional but should be used on a drive that has never been formatted before, if the format type is not Mac OS Extended, if the partition scheme has been changed, or if a different operating system (not OS X) has been installed on the drive.

Creating FAT32 Encrypted Disk Image

I have a 2TB WD external hard drive and am looking to have half of the space used in such a way that it is password-protected and also can be accessed by both Macs and PCs.
I have tried the following:
Disk Utility
New Blank Disk Image
Size: 1TB
Format: MS-DOS (FAT)
Encryption: 128-bit AES encryption
Partitions: Single partition - Apple Partition Map
Image Format: read/write disk image
Received this error message:
"Unable to create "testname.dmg." (File too large)
ALSO:
Disk Utility
New Blank Disk Image
Size: 1TB
Format: MS-DOS (FAT)
Encryption: 128-bit AES encryption
Partitions: Single partition - Apple Partition Map
Image Format: sparse disk image
Received this error message:
"Unable to create "testname.sparseimage." (Invalid argument)
Thank you. Any assistance would be greatly appreciated!
AppleCare was unable to provide a solution.

FAT file system has partition and file size limits, which apparently you exceeded. I think the file size limit for a FAT32 file system is (2^32) - 1 byte.
See here for more info.
http://lmgtfy.com/?q=FATFile+SizeLimit

How can I create a bootable DISK IMAGE of my PB Internal Drive?

I would like to make a bootable image of my Hard Drive but without including any Free Space.
You see all I need on the image are the OSX and the programs, NOT the 60GB of Free Space. Disk Utility however wants to create a 80gb image which includes 60GB of Free Space.
I would like to use the Bootable image as a source image to use with the RESTORE function in Disk Utility.
Regards

You'll need a second machine or an external HDD with Mac OS X installed on it.
For purposes of this procedure I'll be calling your machine the 'source' and the second machine or your external HDD the 'target'.
First either boot the source into target mode by holding down the 'T' key while it boots. Once you see the FireWire icon on the screen, let go of the 'T' key and plug the source into the target. If you're going with the external HDD route, boot your source of off your external HDD.
Now, select the drive of your source machine, and hit Apple-I to bring up the information pane. Down at the bottom (in the permissions area) you'll see a check box labeled "Ignore ownership..." Uncheck that.
Open up Disk Utility. Select the source drive and run First Aid and Repair Permissions on it.
Now, select the File menu -> New -> New Disk Image from Folder. You're going to want to hit that big "New Image" button, but don't. Trust me. It'll only cause trouble for you down the road.
Select the source drive as the source. You can leave everything else the same and click "Image".
Select the target as the destination. Click Save.
Wait for a couple of hours (depending on how much stuff you have).
When it's done, select the Images menu -> Scan image for Restore.
Select the disk image you just made and click "Scan".
When that's done you have a restorable image. Just use the restore tab to restore it.
I've done this literally hundreds of times and it's worked every single time.

Making encrypted disk image takes hours?!

Before I made a Time Machine backup, I wanted to use Disk Utility to create an encrypted disk image on an external hard drive. This way, my computer backup is password protected.
So I set the file for 200G at 128 bit encryption.
That was 12 hours ago. According to the progress bar, Disk Utility is still only one-quarter done with creating the disk image.
Is it normal for Disk Utility to take a full day (possibly two) to create a disk image of this size? Is there any way to create a password-protected disk image quicker? (And, for what it's worth, the external drive is formatted for Mac OS Extended, Journaled.)
Thanks for any advice on this...

Hi, and welcome to the forums.
I'm not quite sure just what you're trying to do.
Are you planning to have Time Machine back-up to that encrypted disk image? If so, that's not going to work. When you start Time Machine, it will create a Backups.backupdb folder on whatever drive or partition you select, then place it's backups in that folder, not in a disk image.
If you want to encrypt your whole home folder, you can use File Vault (System Preferences > Security > File Vault). That will encrypt your entire home folder. But that's almost certainly vast overkill, and has many complications of it's own. Read up on it thoroughly before deciding to do it.
If you have a few files that you want to encrypt, create a (smaller) encrypted disk image on your internal HD, in your home folder. Then copy the documents into it, and securely-delete the originals.
Then TM can back-up your entire system "as is" -- without the overhead of encrypting OSX, your apps, configuration, and everything else in your home folder, but the disk image (and it's backup copy) will still be encrypted.

Creating a LARGE Encrypted Disk Image

Hello,
I have to encrypt a LARGE external Hard Drive for my work (a 1 Terabyte external drive, which comes to about 930 gigs to encrypt).
I have to do one of the regular encrypted disk images, not one of those expandable ones.
I know that encrypted disk images take a long time to create, as I’ve created smaller ones in the past and they take hours.
Does anyone know how long it will take to create an encrypted disk image of this size?
AND, since it will probably take quite a while, I was wondering if it is BAD for my MacBook Pro or the external drive itself to write information for this long of a period. I just want to make sure I don’t damage anything.
Thanks for any help.

I did a 400 GB one and it must have taken an hour to get the password prompt, a couple more for the creation, and another for formatting and mounting.
If you have a bed and sleep daily, as I suspect you do, start an hour before bed, enter the password and it should be done by morning.
You don't need a 900 GB image unless you have one 900 GB file which I doubt. Make one smaller one say 300, then copy it twice. The password will be the same in all 3 copies.
If you look at activity monitor not much is going on during all this so don't think the house will burn down (or your pants - see other question posted today).

Encrypted Disk Image creation slow?

I just got a new MBP with Leopard. I have created a number of encrypted disk images in the past using Tiger and a MBP and have not had any trouble. This weekend I tried a few times to create a 50 gig encrypted disk image (128 AES) on an external drive and after going through the process of setting it up and waiting for it to be created, (and watching the progress bar as it was being created), after about 45 minutes NO progress was showing on the progress bar. I ended up having to cancel the creation a few times because I thought something was going wrong. I’m not sure if there is a problem creating the disk image, or leopard is slow, or what.
Does anyone know how long, on average, it would take to create an encrypted disk image of this size using leopard? I just want to know if there is a problem doing this on my MBP. Thanks for the help.

A regular 50 GB disk image takes 50GB of space, no matter if it is full of files or empty.
A 50 GB sparse disk image only takes up the amount of space equivalent to that of its enclosed files. So if the 50GB sparse image only has 1 GB of files inside, the image won't be much bigger than 1GB.
A sparse bundle is similar to a sparse image, but instead of a single file it is a folder package with many, many enclosed files called bands. A new file added to the sparse bundle will tend to modify only a few bands. This makes incremental backups of a sparse bundle more efficient because only the changed bands need to be backed up again. Any change to a sparse or regular disk image will mean that the entire image will need to be backed up again.
If you regularly add/remove files to a disk image, and you intend to back up that disk image with Time Machine, a sparse bundle is definitely the way to go. The other types will fill up your TM volume very quickly.

Encrypted disk image creation very slow-

I just got a new MBP with Leopard. I have created a number of encrypted disk images in the past using Tiger and a MBP and have not had any trouble. This weekend I tried a few times to create a 50 gig encrypted disk image (128 AES) on an external drive and after going through the process of setting it up and waiting for it to be created, (and watching the progress bar as it was being created), after about 45 minutes NO progress was showing on the progress bar. I ended up having to cancel the creation a few times because I thought something was going wrong. I’m not sure if there is a problem creating the disk image, or leopard is slow, or what.
Does anyone know how long, on average, it would take to create an encrypted disk image of this size using leopard? I just want to know if there is a problem doing this on my MBP. Thanks for the help.

A regular 50 GB disk image takes 50GB of space, no matter if it is full of files or empty.
A 50 GB sparse disk image only takes up the amount of space equivalent to that of its enclosed files. So if the 50GB sparse image only has 1 GB of files inside, the image won't be much bigger than 1GB.
A sparse bundle is similar to a sparse image, but instead of a single file it is a folder package with many, many enclosed files called bands. A new file added to the sparse bundle will tend to modify only a few bands. This makes incremental backups of a sparse bundle more efficient because only the changed bands need to be backed up again. Any change to a sparse or regular disk image will mean that the entire image will need to be backed up again.
If you regularly add/remove files to a disk image, and you intend to back up that disk image with Time Machine, a sparse bundle is definitely the way to go. The other types will fill up your TM volume very quickly.

Any gotchas for encrypted disk images?

I am about to set up e-bills and e-statements at various banks and credit cards and wanted to check a couple of things before doing something that may end up being bad
The assumption I am going with, is I will create an encrypted disk image to store all the PDF's.
1. Is that the right thing to do? Or is there a better way to keep the data secure?
2. If I do so, what is the backup impact? Can I simply set up a task to copy and paste the entire disk image to my external drive?
3. If I want to open the disk image on another computer, can I? How will it authenticate the user/pass on a different computer?
4. I can backup an encrypted disk image to a FAT-formatted external drive?
5. And finally, I have read disclaimers that if I forget the password the data is lost irretrievably. But also, that the password is stored in keychain. So if the password is stored in keychain, the worst-case scenario can only happen if I forget the master password, right? I don't need to truly remember the password to the disk image necessarily, right?

baltwo wrote:
Your profile info indicates that you're running Tiger. If so, post to those forums. If you're running Leopard, update your profile info. What are you trying to protect and from who? Is your computer secure?
IIRC, encrypted disk image passwords are independent from Keychain Access. So if you forget it, then you're hosed. BTW, that's the major failing with encrypted anything. If you forget the password, you're hosed. If the disk image gets corrupted, it's useless with or without the password. Anything stored in an encrypted disk image needs to be backed up in an unencrypted state and stored in some kind of physical thing like a safe. Methinks your a bit paranoid. Disable auto-login, use high-level passwords (that you remember), don't enable the root user account or activate a master password, and you should be secured enough.
I updated the profile. I am running Leopard. So this is the correct forum.
What am I trying to protect? I thought I put it in the first line - statements from banks and credit cards.
From whom? From unwanted entities who may get access to my computer, in any way.
I didn't get the part about the safe. Can I or can I not back up an encrypted disk image to an external drive "as is"? What about possibly opening it up on another computer? And how about putting it on a FAT-formatted disk? I repeat my original questions, but for a reason - they seem to have not been answered.
I do not have auto-login, and I remember my strong login password. I don't have my root account enabled. Under this scenario you think my data is going to be secure? What about if someone were to get control of my computer? Forgive me on this one, I am a switcher so there is a general paranoia about such things which I would like to clarify before reorganizing my life.

Creating an Encrypted Disk Image on an External (USB) Drive

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