[Nottingham] Tape Backup Systems

[Robert Postill]

On 12/04/2008, at 4:52 AM, David Bean wrote:
> Compare the sustained transfer rate of a hard disk to a tape. A modern
> Tape such as an LTO4 can outperform an equivalent external hard disk.
> One issue is that some combinations of RAID arrays, filesystems and  
> file
> usage (lots of small files are bad) cannot provide data quick  
> enough to
> keep up with the minimum streaming speed of a tape.
My experience is that LTO4 is capable of keeping up with low-end  
internal hard disk but if you're backing up any of:
* A SAN/NAS rig
* Fibre Channel drives
*A decent RAID array
*Multpath I/O
you're in bother.  For a heavy workload like that you'll need  
something like a 9840 or T10000 drive.  Although expect a rig with  
that kind of hardware (12 drives, fibre channel interface and  600 or  
so tapes to start at 100k USD) to be a serious money piece of kit for  
the kind of company that's got very deep pockets ;)  I feel like  
we're at a point where we just don't have the capacity for the home  
user or small business/organisation most of us work for any kind of  
responsible backup.  So a couple of hard disks is about the best  
option you've got.

Also I'd say (in a quick Linux gloat) that Windows servers (never  
mind clients) *never* can keep up with Linux/Solaris machines, so all  
this is moot if you have Windows.

Robert