Let's say you have hard drive encrypted with TrueCrypt with HFS+ filesystem on it and you want to use it under both: OSX and Linux. That's no problem because TrueCrypt works great on both systems. But when you want to WRITE to such drive under Linux you'll get an error. That's because Linux do not support writing to journaled HFS. This is how to remove journaling from such drive.

Disabling journalingu on Mac is simple:

• connect encrypted hard drive (e.g. TC-Disk) with TrueCrypt and then
• open Terminal and type:
  diskutil disableJournal /Volumes/TC-Disk

Disabling journaling on Linux is slightly more complicated. Open up a shell window and do the following (comments are in parentheses, the # is the prompt):

• # truecrypt --filesystem=none /dev/sda (TrueCrypt connects drive without knowledge of filesystem type.)
• # truecrypt -l (Look for the mount path of the drive.)
• You should see something similar to:
  /dev/mapper/truecrypt1 /dev/sda
• then:
  # fsck.hfs -fy /dev/mapper/truecrypt1 (The fsck.hfs command to turn journaling OFF.)
• And now you can mount TC-Disk under Linux with read-write permissions:
  # mount -t hfsplus -o rw /dev/mapper/truecrypt1 /mnt/my_encrypted_drive

[crarko adds: I haven't tested this one. OK, it's a little obscure but it might help someone.]

My Macintosh HD startup disk disappeared today, but I was able to use GParted to delete a small partition from the drive and the missing disk reappeared.

Boot Camp Assistant got me into this hot water when I was preparing to reinstall XP. I had partitioned my harddrive into one 276 GB Mac partition and one 5 GB Windows partition, but decided to delete the Windows partition and start over. This time I used BCA and set the size of the new partition to 16 GB.

When running the XP installer, I noticed I was only shown a single 'C:' partition as an option for the install location. The first time I installed XP, I remember seeing two partitions listed with 'Unpartitioned space' between them in the list. Something didn't seem right, so I exited the installer and rebooted, holding the option key for the boot menu.

I was shocked to discover that my 'Macintosh HD' startup disk was gone... only a 'Windows' disk was available (not the install CD). I booted from the Snow Leopard install DVD and ran Disk Utility. It showed no partitions at all on the drive, and the verify and repair options were grayed out.

Yes, I had a Time Machine backup to restore from, but before doing that I decided to try booting from a GParted LiveCD.

Unlike in Disk Utility, the drive did appear to be partitioned, and I saw my large HFS+ partition (unlabeled, though) and another small partition. Although I was unable to 'check/repair' either of them with GParted, I was able to delete the 16 GB partition. After that, the 'Macintosh HD' label reappeared, the check command ran without a hitch, and I was able to boot back into Snow Leopard, without any data loss to speak of.

This Apple Support discussion describes a similar experience. I wonder if others have run into trouble using BCA?

[crarko adds: I haven't tested this one. Keep those backups up-to-date, folks.]

Installing a new OCZ Vertex II SSD in an old 2006 iMac really speeds things up (and is documented in photos here).

However, I was searching for ways to limit the wear of my SSD (since each cell has a limited lifetime with regards to writes). One solution was to store the Safari cache on a RAM drive which will only be written to disk at logout.

Several hints on this site describe a way to store Safari cache on a RAM drive. However, none seemed to work for me because:

• Some RAMdrive creators were not available for download anymore (EsperanceDV).
• Other scripts did not provide a way to store the cache to disk at logout.

Transferring a Time Machine backup to a larger disk can be challenging, as a simple file copy operation in the Finder does not work.

The entire volume has to be transferred in one piece, sector by sector. Disk Utility can usually do this by creating an interim image, but that requires an even larger disk as a temporary storage medium.

This hint is a bit more low level, but once understood, pretty simple: Copy all volume blocks to the new drive, then adjust the volume's size to match the new, larger, partition. That's it.

Using some shell scripting + crontab + Dropbox, I've created a method for doing a daily encrypted backup of folders, lasting for 31 days.

Why bother? It's important to back up data because eventually all drives will die. Incremental backups are important because it allows you to track changes from day to day. The solution I have here isn't perfect, but it allows for a few folders to be saved for 30 days before they are overwritten. The benefit of this is that if a huge error is caught 5 days after it was made, then you can revert to the file that was saved 6 days ago.

I recently had a disk problem where RAID Utility said the disks and volumes were all fine but the volumes were simply absent in Disk Utility. I was at a total loss for what to do, since the system didn't even see any volumes to boot from unless I booted from the install disk, in which case the installer couldn't see any volumes to install on (although it would let me run Disk Utility and RAID Utility). Searching on the web, many people seem to have had a problem like this, but nobody ever came back to report if or how they fixed it.

Time Machine, while it does have a very usable interface, is inclined to get stuck sometimes.

Occasionally Time Machine seems to be stuck, but isn't really. When you first do a backup, or when you haven't backed up to a particular disk for ages (perhaps if you have been away on a trip), it can spend several hours 'preparing'. You can tell it is preparing because when you open the Time Machine preferences there is the little barber pole saying 'Preparing.'

The essence of the solution is to open up the backup media and find the file ending in '.inProgress' and then deleting that file. This will be on the backup volume inside the Backups.backupdb folder, and then in the subfolder for the machine and volume which was being backed up at the time of the hangup. These folders may be inside of a Sparse Disk Image if the backup goes to a Time Capsule or other network based backup volume. After rebooting the Mac Time Machine can then startup normally and perform its operations.

For more details and some screenshots see my blog.

[crarko adds: I haven't tested this one. It's worth it to read the blog entry and pay attention to the caveats and the screen shots contained therein. I've been fortunate to not have any problems with Time Machine, but I've had clients who experienced the hangup using a Time Capsule or an Xserve based backup.]

While Apple's bundled Disk Utility application reports a hard drive's S.M.A.R.T. status, the information might not be correct.

If you care about the information stored on a hard drive that is connected to an internal bus of your Mac, you should consider using other applications than Apple's Disk Utility to monitor that drive's health.

As can be seen in the following screen shot an HDD riddled with bad blocks is still reported as having it's S.M.A.R.T. status verified.

Here's a screenshot showing the difference between Disk Utility and SMART Utility at displaying the S.M.A.R.T. parameters.

[crarko adds: S.M.A.R.T. in general has not been incredibly successful at forecasting drive failure. Here's the report from a study Google conducted on predicting drive failures and the conclusion is that some SMART parameters are more useful than others, but "Given the lack of occurrence of predictive SMART signals on a large fraction of failed drives, it is unlikely that an accurate predictive failure model can be built based on these signals alone."

There's still no better defense against drive failure than known good backups. RAID 6 is nice too, but not found on too many desktops.]

While there are numerous well-documented ways to prevent a hard disk or USB drive from mounting at boot-time, I found only one way (working in 10.6) to prevent newly-connected disks from auto-mounting while logged in.

If you, like me, get annoyed by the index files Spotlight creates any time you create an external hard drive, you might want to try this hint. We're going to set up a launchd service which runs a script every time a hard drive is mounted. This script will touch the .metadata_never_index file (which prevents Spotlight from creating the index; see this hint) on the hard drive.

Let's start with the launchd service. Open Terminal and type the following, then press Return:

$ cd ~/Library/LaunchAgents/ 

Create the file com.index.no_index.plist with your favorite editor (vi, nano, etc.), and insert the following XML code: Do not forget to change *YOUR_NAME* to the name of you home folder. If you don't know what to put there type echo $HOME in Terminal.