esata

[jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org (Jarod Wilson)]

On Nov 19, 2009, at 11:01 AM, Stephen Adler wrote:

> I want to expand the disk capacity of a server which is stuffed with 
> drives already. So now I'm thinking that I should consider an external 
> device which holds several sata disks. This is my first exposure to 
> external sata drives and I want to make sure I'm not doing something 
> dumb. One thing which I've noticed is that the usual one drive per sata 
> port does not seem to apply. The external boxen I've found on the net 
> have a single esata port which drives multiple disks. So, if I buy one 
> of these external drive enclosurs and install two drives, will linux see 
> the two drives individually as /dev/sdc and /dev/sdd? Or will I only see 
> one raided drive. These boxes seem to have raid built into them.

A lot of them do NOT have RAID built-in, they actually rely on the controller they're hooked up to for RAID functionality. Many of these boxes come bundled with an eSATA controller for that very reason. A single sata port off your motherboard with an external bracket may not actually support port multiplexing, which is necessary for these multi-disk boxes.

> Since 
> I'm currently using software raid on my linux setup, I want to have 
> access to each individual drive so I can add them to my current raid array.

Most of them that I've seen do off JBOD mode.

-- 
Jarod Wilson
jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org