On Fri, Oct 29, 2010 at 10:25 AM, Les Mikesell <lesmikesell AT gmail DOT com>
wrote:
> First backuppc uses a native tool to transfer files. Then it checks the
> file contents against the pool with a hashing mechanism, and replaces
> any exact matches with a link to the existing pool copy.
>
>> For instance: I can understand how tar over SSH transfers files. But
>> who decides what files to transfer?
>
> Your file include or exclude lists are mapped into the options
> appropriate for the xfer program with the 'share' as the top of the tree.
So in effect, BackupPC doesn't do anything directly, but rather
indirectly by proxy? (not the network meaning, but the literal
meaning).
>> Does BackupPC crawl the share
>> first and build a filelist? Or is there an option for tar that takes
>> care of if for BackupPC?
>
> With tar and smb, backuppc doesn't know much about the remote side - it
> just passes the options to the program. Tar runs over ssh entirely on
> the remote side.
So with tar/smbtar for a full backup all files are transferred? In
other words there's no checksum on the remote client to see if it
already exists?
>> For SMB I understand that it would just look like a local filesystem
>> after the share is mapped to the BackupPC server. Then what? Does it
>> use rsync against the network share?
>
> The smb method actually uses the smbtar program so it looks more like
> tar than a mapped file system.
>
> The rsync method runs a native rsync via ssh on the remote side, using a
> perl implementation on the server. Rsyncd is similar, but talks to a
> standalone rsync running in daemon mode that must be set up on the
> target. Rsync sends the entire directory tree you request from the
> remote, then both sides walk the list to find and send differences.
I assume that the checksuming that rsync does can create quite a CPU
load on the client which is why on linux clients are often nice'd? (or
ionice?)
Richard
------------------------------------------------------------------------------
Nokia and AT&T present the 2010 Calling All Innovators-North America contest
Create new apps & games for the Nokia N8 for consumers in U.S. and Canada
$10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing
Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store
http://p.sf.net/sfu/nokia-dev2dev
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
|
