[mythtv-users] Single partition or whole disk

[f-myth-users at media.mit.edu]

It's always possible to ignore partitioning and create filesystems
across an entire drive (or, really, any block device, of which a
single whole disk drive is a particular example).

However, it's generally -safer- to use a partition, because that way
various other tools know that the drive isn't uninitialized or blank,
just because it doesn't happen to be partitioned.

(For example, some OS installers may falsely conclude that they should
write a partition table onto that drive, which would wipe out the
first few blocks of your filesystem.  Ditto if something decides to
try to create a boot sector.  And -you-, sometime in the future, may
get your unpartitioned xfs-containing disk confused with some
brand-new disk you're installing---and partition the wrong one.
This is especially likely if you've just installed the new disk
and your OS reassigns the drive letters in a way you don't expect.)

If you haven't written to it yet, I'd recommend creating a partition
table on it (which will blow away your new, but presumably empty, xfs
filesystem), and then creating your xfs on /dev/sdk1 instead.  It's
certainly far easier and safer to do this now than to change your mind
later, which will likely require copying all the data somewhere else
first before you partition the drive.

(In theory, it should be possible to shrink a filesystem, move it to
the end of the drive, partition, and then move it back, except for two
problems: (a) partitioning the device, even into a single partition,
might make the actual filesystem hard to access using normal tools
even if you haven't overwritten any actual filesystem blocks, and (b)
xfs has never implemented support for shrinking.)