On Fri, Oct 19, 2007 at 10:46:59AM -0700, JJB wrote:
> Hello,
> 
> Does Amanda's mac and windows client software allow open files to be 
> backed up the way that commercial backup software like EMC Retrospect 
> (what we are using now) does?
> 

Haven't heard any problems with Mac's as they now are basically
another varient of unix.

Windows makes it a real pain in the arse to get good backups.
Mostly permissions and the open file problem you mention.

There are three ways typically used by amanda to backup windows:
 - use windows software to backup the system to a file,
   use amanda to archive the created backup file
 - use samba's tar-like capability to pull the files from the PC
 - install cygwin software on the PC to make it look like a unix
   client and use gnutar to push the files from the PC

A fourth, I think less often used method is to mount the PC shares
on a unix/linux client using NFS, smbmount, or Sharity, and backup
up the mounted shares using gnutar on the unix client.

Using the first technique, windows software, whether open files
are backed up depends on the windows software capabilities.  It
also suffers during recovery as that must done in be two stages
and amanda doesn't not know what files are stored in the backup
file.  I've seen it used most often for limited PC backup.  Maybe
you set aside a directory tree and only that tree is backed up.

The other techniques all suffer from the inability to backup open
files, system files, and the registry (directly).

> I tried to find info on this by doing a Google search and came across 
> only one post that said something like "you need to use VSS for that" 
> without any information about what VSS might be.

VSS is ?volume shadow ???  I think.  It is a technique for making
snapshots of a windows directory tree.  Backing up the snapshot
would eliminate the problems (except the registry).  My limited
attempts to use VSS suggested that it is not likely to be used
by amanda.  Unless PCs were made an exception and specific code
were developed for PC backups by amanda.  The biggest limitation
I came across was the snapshot only existed for the life of the 
process that created the snapshot.  Further, only that process,
and its direct decendents (child processes) could access the
snapshot.  That is a major difference from the way amanda is
designed.

I personally only rely on PC backups by amanda for user data.

jl
-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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