Phil Schwan wrote:
> I have a question: how much of the Irix functionality do we really
> care about?
>
> Who exactly is the intended audience of this utility, and in what
> capacity do we expect them to use it? Is this being provided
> basically as a simple ext2->xfs migration, or do we expect users to
> use this for their real backups?
>
> I'm also vaguely curious about why every dump that I've seen to date
> chooses to open the device and parse the FS metadata itself. The only
> reasons that I could come up with were hard links and atime, both of
> which can be kludged around. Presumably there is another reason that
> I'm not aware of: can anyone enlighten me? SO much complexity can go
> away if we treat dump as a smarter tar (my guess is at least an order
> of magnitude in terms of lines of code).
You are assuming the file system you are dumping is mountable and in
a deceit shape. Dump is very tenacious about trying extract as much data
from a file system that has been corrupted. I've managed to recover
several
file systems from bad disk drives by using dump.
The strangest one I ever ran across; was disk drive that put it self into
read only mode.
This was a problem since the super block was not marked clean, and
the drive wouldn't allow it to be marked as such, thus the drive was
un-mountable. Dump happy read the entire file system and we were
able to get the system back up and running with a new drive in short
order.
Why xfsdump was written such that it requires a mounted filesystem
escapes me.
Also being able to dump and restore a file system from minimally running
system
(In cases of root drive failure) was also a necessity.
At the time dump was written really huge floppy drives (1.4meg) :-)
wasn't available and CD-ROM??? what's that?
If it is just a ext2 -> xfs path we are looking for... then we should
just call it tar.
If we want to provide a way of restoring a "dumped" file system to xfs
then
we don't need dump just restore.
If we want people to use xfs in an environment where they are using dump
to to backups then we need dump, especially if they run with a mix
of file systems.
>
>
> I'm happy to keep plugging away with the port, I just want to make
> sure that our needs wouldn't be better served with a quick rewrite.
>
> -Phil
|