RE: Active/Passive "high availability"

Summarizing all the below comments as (SAN = SPOF != HA), I would argue that it depends on how you define "high availability". The term is inherently subjective. Even if you are down 10 days a year, that is still relatively "high availability" compared to being down 20 days per year. Certainly a fully redundant SAN with a competent admin is going to be more highlier (obscure South Park reference :-) available than a single spindle with no redundant components. A careless, but efficient, tech can bring down multiple SANs for quite a long time :-)  

From: Jared Still [mailto:jkstill_at_gmail.com]

Last time I looked, a mirrored disk resides in some type of disk farm. SAN, NFS, whatever, it is a SPOF.

SAN failures are not exacly unheard of.  

 No, it doesn't require multiple failures. I am not a storage expert, but having redundant components in a SAN does not make it HA. It makes it more resistant to failiure, but it cannot be relied on to guarantee a high percentage of availability.

I have also seen SAN's fail more than once.

1 SAN = SPOF    It isn't really necessary to have a physical disaster.

A careless tech can bring down your SAN for quite a long time.

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