Subject: Re: other backup technologies?
To: None <current-users@NetBSD.ORG>
From: der Mouse <mouse@Holo.Rodents.Montreal.QC.CA>
List: current-users
Date: 01/06/1997 20:51:49
>> Dump reads from the raw device; restore writes through the
>> filesystem, and every file create involves a bunch of synchronous
>> writes..

> Uh, why?

Why which?

> What's wrong with a fs-neutral dump?

- it can't get holes completely right (at least not without writing to
  the files in question)

- it's significantly less efficient, because it perforce walks the
  filesystem in filesystem-tree order instead of inode order

- it can't help modifying atimes or ctimes

It does exist, though; it's called tar.

> Is restore fs-neutral?

Yes; restore runs atop the usual filesystem interface.  That's exactly
why it's so slow - it's doing lots of file creates, and each one
involves a synchronous write of a directory block and I think an inode
block as well.

					der Mouse

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