MacOS

I got a new iMac and wanted to use an USB-drive as Time Machine backup destination for it. When it comes to easily movable backup-drives, my policy is to encrypt them. If a drive is lost/stolen/misplaced, other people don't get to access my data.

When OS X sees an empty USB-drive, and there is no Time Machin already set up, it asks if you'd like to use the newly found drive as Time Machine backup destination, which is nice and user friendly. During Time Machine setup, there is a checkbox "Encrypt drive". I checked it, but whatwhatwhat?! It refused to work. Error message:

There was an error preparing the Time Machine backup disk "TimeMachine" and an additional explanation: The given file system is not supported on Core Storage.

Well... that's strange. I have no idea what a Core Storage is, or why an Apple formatted HFS+ partition would not be a valid (encrypted) backup destination.

Here is what I did. My drive was already formatted when I got it:

$ diskutil list disk3
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk3
   1:                        EFI                         209.7 MB   disk3s1
   2:       Microsoft Basic Data WD Backup               1000.0 GB  disk3s2

There is a 1 TiB Western Digital drive with a NTFS-partition on it. So I had to delete the partition and create a better suitable one:

$ diskutil partitionDisk disk3 1 GPT HFS+ TimeMachine 1T
Started partitioning on disk3
Unmounting disk
Creating the partition map
Waiting for the disks to reappear
Formatting disk3s2 as Mac OS Extended with name TimeMachine
Initialized /dev/rdisk3s2 as a 931 GB HFS Plus volume
Mounting disk
Finished partitioning on disk3
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk3
   1:                        EFI                         209.7 MB   disk3s1
   2:                  Apple_HFS TimeMachine             999.9 GB   disk3s2

This is the partition setup that refuses to work.

After couple of hours of Googling I found the solution:

$ diskutil enableJournal disk3s2
Journaling has been enabled for volume TimeMachine on disk3s2

I seem to have misplaced the links already. Sorry. Anyway, the problem was that I didn't enable journaling on the partition. I can understand why that is a requirement for Time Machine. Having a journaled partition adds robustness to write operations. The real questions are:

• Why creating a HFS+ partition does not enable journaling automatically?
• On Linux creating EXT2 or EXT3 partition does not enable journaling automatically
• On Linux creating EXT4 journaling is enabled by default
• Why doesn't Time Machine state the reason?
• Saying that Core Storage is not supported is a bit vague!

Something weird happens in OS X Terminal locale settings. Whenever I open an SSH-connection to one of my Linux-boxes, they refuse to properly set up an UTF-8 locale.

The session goes something like this. Checking locale settings on OS X terminal:

$ locale
LANG=
LC_COLLATE="C"
LC_CTYPE="UTF-8"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL=

Open SSH-connection and check locale settings on Linux end:

~> locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
LC_CTYPE=UTF-8
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

Aow come on! Something went wrong.

The fix on the OS X end is not to set the environment variables. In the Terminal settings, there is:

The setting Set locale environment variables on startup needs to be UNset. It is checked out-of-the-box. Then it yields:

$ locale
LANG=
LC_COLLATE="C"
LC_CTYPE="C"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL=

The LC_CTYPE is not set. Over SSH-connection to Linux, it yields:

~> locale
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

Now there are no error messages. The next thing to do is to try to find somebody responsible. Whose job it is to fix this.

Earlier I wrote about getting a Linux-based NAS-box to host Apple Time Machine backups.

I was reviewing my settings on the Mac and realized the text in the Time Machine:

Well... I have lots of disk space there. Not all of it is can be taken by my Mac's backups, so ... Something needed to be done.

I mounted the AFP-share and confirmed the max size of my sparsebundle:

hdiutil imageinfo Mac\ mini.sparsebundle/

It said (unsurprisingly):

Size Information:
 Total Bytes: 8855484092416

That is 8+ TiB!! Oh my! There is no way that I can afford to have that much of Apple backups. Luckily there is a way to reduce the size:

hdiutil resize -size 500g -shrinkonly Mac\ mini.sparsebundle/

Now checking the size will yield something reasonable (500 GiB):

Size Information:
 Total Bytes: 537214885888

That is something, that I can easily accept.

The information came from:

• http://untoro.wordpress.com/2011/06/07/how-to-limit-space-used-by-time-machine/
• http://nikhilhaas.com/blog/limit-size-of-time-machine-backup-on-wd-my-book-live/

Also I did this to limit the size. I have no idea if it actually does anything.

defaults write /Library/Preferences/com.apple.TimeMachine MaxSize 405600

Perhaps somebody can comment this.