On Wed, May 11, 2005 at 10:24:58AM -0400, Piszcz, Justin wrote:
> I was curious if anyone here is backing up large amounts of data, such
> as large databases and fileservers that are 3TB or bigger.
> 
> What is the best way to accomplish such backups?

Multiple streams over multiple network interfaces.

> If one can sustain 100 megabytes per second over a gigabit link writing

There is *NO* way you can sustain 100 megabytes per second.  That's all
the interface is physically capable of and you'll be lucky to get half
that.  

Databases at least have larger files.  If you have a fileservers with
lots of little files, you're in for some serious hurt.  It can take us
12+ hours to back up a 250GB volume and that's going to a disk staging
storage unit with a gig network between the client and the media server.

> What are some good methods when backing up such large data sets?

The question should always be not what the method for backup should be,
but what the restore requirements are.  Work your way backwards - do you
really need a full backup every day?  How much data can you afford to
lose if you lost the array?  Can you back up your database weekly with
daily or hourly archive logs?

I've got a 100 TB sitting on my SAN plus many more on local disks but I
don't do a full backup of every byte every day.

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts AT ewilts DOT org