Formatting hard drives

[Hartie]

Which one is more recommended to format hard drive, latest ML or 10.6.8?

If i format using 10.6.8, do i lose any features when later plug that drive to ML?

[fracai]

Each will format the drive in the same way.

[DeltaMac]

There is no different between those two, assuming that you would format with the default Mac OS Extended format.
I tend to format on the same system where I might typically use the drive, but Apple hasn't significantly changed the MacOS Extended format for about 15 years (since Mac OS 8.1) - although the partition map has been changed, because of the advent of the Intel processor, when the GUID partition table was added. However, that doesn't affect how drives can be used, nor provide any change in the feature set, in any significant way.

[acme.mail.order]

Assuming this is an external drive you just bought, there is a difference between format" and "partition". A lot of external drives come bundled with software you really don't want plus some odd cross-platform bits.

Open Disk Utility in 10.6 or newer, select the drive (not the volume) and choose "Partition". If you don't see it, you have not selected the right part. After that it should be obvious.

[ganbustein]

Quote: Originally Posted by DeltaMac I tend to format on the same system where I might typically use the drive, but Apple hasn't significantly changed the MacOS Extended format for about 15 years (since Mac OS 8.1)

Actually, Apple has made a LOT of changes since then.

For OS X, they had to add the ability to have two blessed folders (one for MacOS and one for OS X) and the ability to create hard links, which Unix pretty much requires. They also had to add Unix file permissions.

On Tiger, they started adding extended attributes, and turned them on by default in Leopard. I think Tiger is also when they added Journaling and the Hot Zone and the case-sensitive filename option. None of those existed pre-OS X. All of them require changes to the format of the catalog data structures.

Leopard added the ability to make hard links to directories (needed by Time Machine). Extended attributes (also needed by Time Machine) were now reliable enough to have enabled by default. (Extended attributes are stored in an XATTR fork that didn't previously exist.)

Snow Leopard added transparent file compression. (A file without a resource fork can have its data fork compressed into the resource fork. If that's small enough, it can be stored directly in the catalog instead of in an external extent.) The XATTR fork, if small, can also be stored directly in the catalog. A directory named "Contents" that is the only child of its parent directory is now just a single bit in the parent's catalog entry.) That compression, plus the omission of support for Classic, is why Snow Leopard takes significantly less space on disk than Leopard.

Lion added new HFS+ features to support versions. If you explore inside /.DocumentRevisions-V100/PerUID, you'll find lots of files that appear to be complete copies of versions of files you've worked on. Except that according to du, they're all empty. Lion's version of HFS+ hides from you the fact that the content of these files is no longer stored in a traditional fork, but is instead assembled on the fly by pulling data fragments out of an sqlite database.

HFS+ (Or MacOS Extended, as it is now called) is anything but a stationary target.


But back to the main question...

Erasing a volume (as opposed to re-partitioning) treats Recovery HD partitions differently depending on OS. The Snow Leopard (and earlier) version of Disk Utility doesn't know anything about Recovery HD partitions, and leaves them untouched. On Lion and later, when Disk Utility erases a volume that is followed immediately by a Recovery HD partition, it merges them before erasing. (If you then install Lion or later on that partition, the installer will carve out a fresh Recovery HD partition.)

[DeltaMac]

Fair enough (enough, already with the details! )

After I posted, I realized I was being a bit "near-sighted" in my comment about "no significant changes", and expected someone to show me up on that.
Thanks, ganbustein!

How about this, then?

Quote: Whenever possible, use your newest OS X system to format your hard drive.

[ganbustein]

Quote: Originally Posted by DeltaMac How about this, then? Quote: Whenever possible, use your newest OS X system to format your hard drive.

With that, I heartily agree.

[MariaPeter]

Quote: Originally Posted by Hartie Which one is more recommended to format hard drive, latest ML or 10.6.8? If i format using 10.6.8, do i lose any features when later plug that drive to ML?

I faced the same situation few days back, and I did using Snow Leopard. Though I hadn't face any problem, havn't loose any file or feature but its always recommended to take backup before formatting, upgrading, or downgrading. Take bakup and use 10.6.8 to format.
Gud Luck!!