Re: [rdiff-backup-users] Atomicity of backups?

[Ben Escoto]

>>>>> "DG" == dean gaudet <address@hidden>
>>>>> wrote the following on Tue, 10 Dec 2002 11:13:32 -0800 (PST)

  DG> for performance reasons you'd batch things up -- create a bunch
  DG> of temporary files, log all their names / relevent data, flush()
  DG> and fsync() your log, then begin moving the files into place.

I see, thanks for the outline.

  DG> you actually don't even really need a log per se -- if the
  DG> filesystem is a logging filesystem, and your temporary filenames
  DG> are appropriately named so that you know where they belong, then
  DG> the contents of a single temp directory serve as your log :)

Very clever, but I don't think there can be a single temp directory
because we may be dealing with multiple file systems, and a file can't
be renamed across file systems.

    Also other things may happen besides files getting moved.  There
may be deletions, or metadata changes (as when a directory's mtime
gets updated after we leave it).  I guess I will have to come up with
some language for expressing the various operations.


-- 
Ben Escoto

pgpzPrvRORxQa.pgp
Description: PGP signature