load balancing at fastmail.fm

[David Carter]

On Mon, 12 Feb 2007, urgrue wrote:

> SAN really has nothing to do with replication. You have your data 
> somewhere (local or external disks, local/ext raid, NAS, SAN, etc), and 
> youve got your various replication options (file-level, block-level, via 
> client, via server, etc).

I agree that storage and replication are orthogonal issues. However, if a 
lump of storage is no longer a single point of failure then you don't have 
to invest (or gamble) quite as much to make that storage perfect.

Software is rarely perfect, as the early history of replication in Cyrus 
2.3 demonstrates. If the software isn't itself a single point of failure 
then it can at least be monitored and fixed. On which note I should pass 
my thanks to Bron Gondwana, Wes Craig and anyone else who has been working 
on replication there.

> None of these are a replacement for backups.

Absolutely, I agree. Exterprise storage and replication are both just 
strategies to reduce the frequency that you need to resort to backup.

-- 
David Carter                             Email: David.Carter at ucs.cam.ac.uk
University Computing Service,            Phone: (01223) 334502
New Museums Site, Pembroke Street,       Fax:   (01223) 334679
Cambridge UK. CB2 3QH.