Re: Raid selection questions (10 vs 6, n2 vs f2) on an 8 drive array

[NeilBrown <neilb@suse.de>]

On Fri, 18 Feb 2011 12:55:05 -0800 Larry Schwerzler <larry@schwerzler.com>
wrote:

> 2. One problem I'm having with my current setup is the esata cables
> have been knocked loose which effectively drops 4 of my drives. I'd
> really like to be able to survive this type of sudden drive loss. if
> my drives are /dev/sd[abcdefgh] and abcd are on one esata channel
> while efgh are on the other is there what drive order should I create
> the array with? I'd guess /dev/sd[aebfcgdh] would that give me
> survivability if one of my esata channels went dark?

Yes, in md/raid10 the multiple copies are an 'adjacent' devices (in the
sequence given to --create).

Of course, you wouldn't actually use the string  /dev/sd[aebfcgdh]
as that expands matches in alphabetical order.:


$ echo  /dev/sd[aebfcgdh]
/dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh

Instead use this:

$ echo /dev/sd{a,e,b,f,c,g,d,h}
/dev/sda /dev/sde /dev/sdb /dev/sdf /dev/sdc /dev/sdg /dev/sdd /dev/sdh

NeilBrown