Can multiple nginx instances share a single proxy cache store?

[Isaac Hailperin]

Hi,

I am planning to deploy multiple nginx servers (10) to proxy a bunch of 
apaches(20). The apaches host about 4000 vhosts, with a total volume of 
about 1TB.
One scenario I am thinking of with regard to hard disk storage of the 
proxy cache would be to have a single storage object, eg. NAS, connected 
to all 10 nginx servers via fibre channel.

This would have the advantage of only pulling items into cache once, and 
would also avoid cache inconsistencies, which could at least be a 
temporal problem if all 10 nginx servers would have their own cache.

My question now is: would this work in theory?
Can multiple nginx instances share a single proxy cache store?
I am thinking of cache management, all 10 nginx instances would try to 
manage the same cache directory. I don't know enough about the cache 
management to understand if there are problems with this scenario.

Strictly speaking this is a second question, but still: the alternative 
would be to give the nginx local storage for the proxy cache (e.g. a 
raid 5, or even jbod (just a bunch of disks)). This would obviously be 
much simpler to set up and manage, und thus be more robust (the single 
storage would be a single point of failure).
Which would you recommend?

Isaac