Paul E Condon wrote:
I'd like some confirmation, or refutation, of some reasoning:
I have a USB external hard drive. It came with vfat fs, but I want to
write an ext2/3 fs on it. All my internal HD are ext3, but should this
one be ext3, also? Doesn't ext3 essentially write everything twice,
first to the journal, and then to the actual target location? This is
OK with an internal bus interface from the CPU to the HD, but USB is
not so fast. So I think I should not use ext3 for this HD. Is this
correct?
TIA
Basically ext3 is ext2 with Journaling. Journaling basically
safe-guards against power failure and system crashes. It is well
suited for system partitions and partitions that are being used
most of the time your computer is on.
Journaling uses significantly more disk space and does not allow for
deleted file recovery. IT uses more resources that ext2. Journaling
does not write everything twice. It keeps track of the file system
which makes recovery fast and more reliable than file systems
without Journaling.
I recommend the following:
ext3 - for system partitions and data partitions which are in use
most of the time (/, /home, /var, etc. if they are separate
partitions or drives).
ext2 - for backup, removable, partitions rarely used, etc.
If your USB external is for backup or file transfers then I
recommend using the ext2 file system on it. Logic being that if
your USB external data gets corrupted then you still have a copy of
the data on another partition.
FYI:
Some people confuse backup with archiving. They will make copies of
their data and store it away until they have data problems with the
system. This is archiving.
Backup is a never ending routine whether done once a week or one a
month and also include regular data integrity checks of the backups.