[OpenAFS] Anybody using BackupPC4afs ?

Stephen Joyce stephen@physics.unc.edu
Sat, 17 Nov 2007 13:42:14 -0500 (EST)

On Thu, 15 Nov 2007, Hans Melgers wrote:

> I was wondering if anybody on this list is using this for afs backups ? can 
> you recommend it ? pro's/cons ?
> http://www.physics.unc.edu/~stephen/BackupPC4AFS

Well... I am. But I'm a bit biased. :-) I've been using it for over a year for 
backups and restores without problems.

If your site is using BackupPC4AFS, please drop me a note and let me know. It 
gets quite a few hits and downloads on sourceforge, but I'm only aware of one 
other site using it. Feedback, ideas, bug reports, and especially bug fixes, 
are most welcome.

I won't discuss the pros/cons of METHODS of backing up AFS (dumping volumes vs. 
backing up files). That discussion has been rehashed on the list several times 
and is available via google. BackupPC4AFS backs up volumes.

Here are some pros:
  BackupPC itself is a fairly mature application and the logic for when and what 
to backup is damn-near bulletproof.

  BackupPC4AFS just uses BackupPC's logic and much of its code, but instead of 
connecting to PCs, it backs up and restores AFS volumes.

  In a worst-case scenario, restores can be performed outside BackupPC4AFS. 
They're in standard AFS vos dump format.

  The CGI makes it really easy to add new volumesets, see how much space backups 
are consuming, view the logs to make sure that everything went well, and 
perform restores. It's easy to configure email alerts if there are problems.

  It's much faster than dumping to tape. With modern linux servers and raids, 
15-25 MB/s is normal over GigE. My fastest recorded dump is 43.28GB in 17.0 
mins (42.5MB/s).

  It has some neat features like exponential expiry that make it very 

  It's free (GPLed) and of course you get the source. If it doesn't perform as 
you want, you're free to make changes, and hopefully contribute them back.

Here are some cons:
  There is presently only 1 developer (you can consider this another plea for 
testers, feedback, and, if you have skills, code). I'm only aware of one other 
site that's using it.

  There are definitely places where the code isn't pretty.

  The install is straightforward, but the configuration--while easier than the 
native AFS backups--can take a bit of time.

  The initial "breakin period" can be cumbersome. For example, I do a full of 
only 1 volumeset most nights (all other volumesets get incrementals that 
night). During transition it can become monotonous to add 1 new volumeset each 
day. If you have a very small cell, you don't need to do this, but for any cell 
with more than ~500GB, it's almost mandatory to spread your full dumps out over 
several days/nights in order to keep your backup window small.

  It's assumed that you're doing disk-to-disk backups. If you want a copy on 
tape, you have to use another product to grab the dumpfiles, use BackupPC's 
archive function to interface to another product, or have the other product 
dump its own copy.

  Currently the AFS restoration mods are only present in the English 

Future plans:
  Upgrade to BackupPC 3.1 codebase once it's released. Most of its changes 
aren't applicable to AFS, but I want to stay up to date.

  Add the AFS restoration mods to the other language files; preferably with 
human help, but since I'm not a diplomat or journalist, with google as a last 

  Add an option to compress the dumpfiles to save disk space.


Hope this helps!

Cheers, Stephen
Stephen Joyce
Systems Administrator                                            P A N I C
Physics & Astronomy Department                         Physics & Astronomy
University of North Carolina at Chapel Hill         Network Infrastructure
voice: (919) 962-7214                                        and Computing
fax: (919) 962-0480                               http://www.panic.unc.edu

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