Backups

Kent Borg kentborg at borg.org
Fri Aug 25 18:34:54 EDT 2006


rsync also has a great "--link-dest" feature.  You can use it like
this:

  - Make a backup from source to /someplace/A.  

  - A week later, say, when you want to make an incremental backup, do
    another rsync from source to /someplace/B, but this time add the
    option "--link-dest=/someplace/A".  

  - And the time after that do a backup to /someplace/C with
    "--link-dest=/someplace/B".  

  - And so forth.

What you will get is a series of complete backups (A, B, C, etc.), but
for any files that didn't change between backups the data will be
stored only once, with multiple hard links from each A, B, or C that
included that version of the data.  So the incremental backups, though
each is complete, can be very small, all without any compression or
other tricks to keep you from using your backups quickly and easily.

One consideration: if you have something like a large mail file that
gets bigger every day as you don't delete stuff, but is never the
same, it still gets stored in its entirety every time.  

A more general consideration: Don't just worry about how to backup,
ask yourself what happens the day you need your data.  Will the backup
be good?  Will you be able to access it quickly?


-kb

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.




More information about the Discuss mailing list