On Fri, 2007-02-16 at 07:38 -0600, Nathan Moore wrote:
> Hello all,
> 
> I have a small cluster of SL 4.4 machines with common NIS logins and  
> NFS shared home directories.  In the short term, I'd rather not buy a  
> tape drive for backups.  Instead, I've got a jury-rigged backup  
> scheme.  The node that serves the home directories with NFS runs a  
> nightly tar job (through cron),
> 	
> 	root@server> tar cf home_backup.tar ./home
> 	root@server> mv home_backup.tar /data/backups/
> 
> where /data/backups is a folder that's shared (via NFS) across the  
> cluster.  The actual backup then occurs when the other machines in  
> the cluster (via cron) copy home_backup.tar to a private (root-access- 
> only) local directory.
> 
> 	root@client> cp /mnt/server-data/backups/home_backup.tar /private_data/
> 
> where "/mnt/server-data/backups/" is where the server's "/data/ 
> backups/" is mounted, and where /private_data/ is a folder on  
> client's local disk.
> 
> Here's the problem I'm seeing with this scheme.  users on my cluster  
> have quite a bit of stuff stored in their home directories, and  
> home_backup.tar is large (~4GB).  When I try the cp command on  
> client, only 142MB of the 4.2GB is copied over (this is repeatable -  
> not a random error, and always about 142MB).  The cp command doesn't  
> fail, rather, it quits quietly.  Why would only some of the file be  
> copied over?  Is there a limit on the size of files which can be  
> transferred via NFS?  There's certainly sufficient space on disk for  
> the backups (both client's and server's disks are 300GB SATA drives,  
> formatted to ext3)

I can't answer your question, but I can suggest an alternative
method.  Before I bought a tape drive, I used a "cron" job running
rsync to mirror a filesystem to another machine:

rsync -az --delete host1:/dir1/ host2:/dir2/

That way only the files which have actually changed need to be
transferred, which cuts down the network traffic to trivial levels...
Look at the man page for rsync for more details.

> 
> I'm using the standard NFS that's available in SL43, config is  
> basically default.
> regards,
> 
> Nathan Moore
> 
> 
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> Nathan Moore
> Physics, Pasteur 152
> Winona State University
> [log in to unmask]
> AIM:nmoorewsu
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