Writing to Encrypted Disk Image SLOW On Mac Pro

I have a slew of Previous Gen (2010/2012) Mac Pro 12-Core 2.66 desktops running 10.8.5 (12F45). When making a standard 128-bit Encrypted Disk Image, the write speed to that image is extremely slow. Disk image is on the same system internal drive as the source material. Also tried on Gigabit Ethernet share. 1GB file takes 20 minutes.
If I take the same disk image and run it on a 2012 Mac mini server 2.6 i7 running 10.8.5 (12F45), the write speed is fast; 1GB takes 1 minute. Same holds true for a MacBook Pro (non-Retina) 2.3 i7 running 10.8.5 (12F45).
Antivirus is disabled on all machines for testing purposes. Mac mini is actually a clone of the Mac Pro's system, so everything is the same, software-wise.
Is there something inherently wrong with these Xeon Mac Pros that they cannot write fast to encrypted disks? Any other variables I'm not thinking of?
Thanks in advance.

The write speed to an encrypted image is around 5.65MB/s in comparison to 92MB/s on normal disk. I feel frustrated to see the remaining time to copy 800GB of data from internal HDD to the mounted encrypted volume takes around 1 day. An encrypted disk managed by Truecrypt on any PC will work much better than it.
iMac (Late 2013), OS X Yosemite (10.10.1)

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Password no longer works with encrypted disk image.

I have an encrypted disk image on my macbook pro. I enter the password every time I open the disk image. Last week it stopped accepting the password. I checked in keychain where I'd saved the PW when first creating the disk image and verified I was entering what was saved there. It matched what I've been entering but still no luck. I attenpted to pull an old version of the disk image from time machine and that still won't open with what I know is the password I've always used.
Any tips?

try doing SMC reset the following article tells how to do that:
http://support.apple.com/kb/HT3964
after doing this reset try again to enter the password for the disk image, if it still doesn't work there is no way to bypass the passcode on the disk. the following article talk about filevault:
http://support.apple.com/kb/PH3683

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.

Encrypted disk image on a network, is the data encrypted during reading/writing?

I'd like to use an encrypted image for storage of sensitive data on an openly accessible network storage. Does anyone know if the data that is written/read from the image (once it is mounted) is transferred over the network in an encrypted or decrypted form?
It's seems important, since if the network connection is not encrypted then the data might be accessible to others.

Efren,
When you mount an encrypted disk image, the machine you are using (and on which the image is being mounted) is handling all encryption/decryption. So yes, the data that is transmitted across the network is already encrypted.
Scott

Corrupted files within encrypted disk images

Greetings Apple Hivemind:
I've run across a repeatable problem when using encrypted disk images from Disk Utility. Essentially, I'll create an image using settings like are shown below:
The disk image is then used for storing data. In my case, this is usually data for Adobe Lightroom.
At first, this worked very well, and I housed the disk images on my household NAS, connecting via samba (smb) to it on my Mac. Over time, however, something odd started happening: Files on those encrypted images began getting corrupted whenever I tried writing new data to them.
My first incident was where Lightroom informed me that the catalog it was trying to open was corrupted. I tried to create a new one on the same encrypted volume, and it too was instantly flagged as corrupted. I opened the individual image files on the volume with no problem, so I wasn't thinking that the volume was the culprit. That is, until I tried dragging new image files to it manually. The new files were immediately either completely unreadable, or a mish-mash of the content of random OTHER files on the volume!
The result was that all old data seemed intact, but I could no longer write new data to the volumes without major data corruption issues. I thought that this was isolated to one volume in particular, but it soon started happening on ALL of my encrypted volumes eventually. Including those which were not, and never had been, housed on my NAS, but were on my local hard drives.
I've since "evacuated" all my data from these images, since the ones created by Disk Utility appear to be useless, and am seeking an alternative.
Is this something that anyone else has encountered when using encrypted disk images? It seems like this is something I should really open a support ticket for, but I can't say I've ever tried it, so I don't know how successful it would be to do so.

bbonn wrote:
I should add that I've tried using the "Repair" and "Verify" functions of Disk Utility on the volumes, and despite the obvious issues that exist in them, the utility doesn't find (or fix) any inconsistencies.
Are you repairing/verifying the actual disk images, or just the partition they're on? If the partition, it won't look inside them.
Drag one to Disk Utility's sidebar, select it, then use Verify or Repair. Note: the usual messages may not appear on the DU window. Click the Log icon in the toolbar or select Window > Show Log from the menubar to see them.

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)

Disk Utility - Create encrypted disk images super sloooow

Trying to create encrypted disk images via Disk Utility on my iMac (i7 8GB) is super-slow in 10.8. It worked quite fast in 10.7, but now it's super-slow and doesn't even seem to ever finish.
I've tried re-installing 10.8 with no difference.
Anyone else having trouble with this? Even a small dmg (~200MB) doesn't seem to work.
Unencrypted images seem to work OK (if not a little slow).
I realize that the encryption process will be slower but something is definately wrong with 10.8 disk utility in this regard. I have 1TB+ free space. I have tried with another user account as well.
My task was: (new disk image, read-write, 128bit encryption)
2012-09-03 08:59:59 -0400: Initializing…
2012-09-03 09:00:00 -0400: Creating…
2012-09-03 09:03:28 -0400: Copying… <<< seems to be stuck here...

Good morning,
Have you tried using Disk Utility from within the recovery mode? (Hold down CMD and R when booting)
I used to have this problem but creating them this way really improved the time.
Give it a go...
Rob

Encrypted Disk Image

Is there any way to have an encrypted disk image warn other users, upon mounting, that it has already been opened or is currently open by someone else? If not, then anything comparable?
This whole situation arose based upon the need of having a password protected folder on the network. Someone then chose as a solution to have an encrypted disk image.
Wouldn't several people mounting and writing to such an image simultaneously cause corruption?
Any workarounds?

Hi flimps,
A couple of things...
1. How did you create the disk image? Did you do it through Disk Utility or a 3rd party program?
2. Are you checking the box "remember this password in my keychain" when you're creating the password or authenticating? If so, your keychain will automatically store that information and "auto fill" each time you want to access the image.

Can a 256 bit encrypted disk image be read by Tiger?

I have computers running Leopard, Tiger and Panther.
If I create a 256 bit encrypted disk image in Leopard, will the image be able to mount and used for reading and writing in Tiger and or Panther?
Or should I use 128 bit encryption in a mixed OS X environment?
TIA,
Bill

Hello Bill,
A 256 bit encrypted disk image created in Leopard can be opened in Panther, and presumably Tiger, though I don't have Tiger.
It cannot however, be written to, only read.
So if you want to add to the disk image on Panther, and possibly Tiger, use 128 bit. But if you only want *read only* on the other machines you could use 256 bit.

Encrypted Disk Image mounts without Password

I've created a new encrypted disk image so that I can store sensitive documents and did it carefully, step by step,(per instructions from www.macworld.com/2425) but after I unmounted, then remount, it doesn't ask me for a password. It just mounts as if it were a regular file. Am I suppose to unmount the volume and drag the disk image to the trash? I don't know what else to try.

The Mac uses and encrypted database of keys called the "Keychain". When you login, it opens the "login" keychain using your login password. That keychain can be used to provide passwords for applications and services, and form data for web sites. In this particular case, the password for your encrypted disk image is being stored in the keychain and automatically provided.
If another user attempted to open the disk image, the disk image mounter would first look in his keychain and then the system keychain for a key to open it with. Finding none, it would prompt the user to specify the key (password). If the user supplies the correct password, the system would put it in his keychain for safe keeping, and the user would then be able to open the image again without supplying the password.
You can remove the key from your keychain by opening up /Applications/Utilities/Keychain Access, selecting the "login" keychain, and then looking for an entry with a name that matches the .dmg file in question. Highlight it, and then press the delete key to delete it. The next time you attempt to open it, it will prompt you for a password.

Cross-platform encrypted disk-image formats?

Is it possible to create an equivalent of an encrypted disk-image in a format that is readable under Windows? I am able to create a .dmg file using Disk Utility in MacOS and define the file-system as DOS, and encrypt it, but .dmg files are not readable under Windows. Some Win utilities claim to be able to read these, but I have not found any that work.
Is there a standard solution for creating a disk-image on my Mac that is not Mac-specific? I want to create an encrypted DOS/FAT file-system disk-image, store files in it, then open it under Windows. Does such a solution exist?
Thanks,
--- Christer

Does TrueCrypt do what you want?
(55088)

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.

Encrypting Disk Images

Hi,
I've followed several guides to create an encrypted disk image so i can hide some private files on my Mac - All the guides said the same way and one was the one here on Apples site and still i have no luck.
I create the disk image and when i put the files in it, eject the disk and try to mount the disk again from the DMG file it doesn't ask for a password. The only solution i can see is that it is because this does not work as i am admin and trying to password a file in my on account? Does this only work for shared folders with other users or is there another explanation as to why this won't work?
Thanks

Well Keychain is really there for your convenience. It remembers your passwords so that you don't have to enter them when they are needed but it is sort of a security risk of you just leave your mac sitting there and your keychain unlocked. However, these passwords can only be used while the keychain is unlocked. An admin password is needed to actually view the password.
You can lock an unlock the keychain manually or have it lock automatically after a certain amount of time (in keychain access go to Edit -> Change settings for keychain "login") or when your mac sleeps. But you might want to consider the security of your mac as a whole instead of just the keychain. For example: is it easier to keep the keychain locked or is it easier to prevent access to your computer as a whole (like disabling automatic login and requiring a password from waking from sleep?).
Steve

Writing to Encrypted Disk Image SLOW On Mac Pro

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