Re: Two sanity checks

Nuno Souto <nsouto_at_optushome.com.au.nospam> wrote in message news:3c6289b2.6976670_at_news-vip.optusnet.com.au...
> If given the choice I'll always take the SAN: re-configuring the darn
> things is soooooo much easier than fiddling around with controllers,
> disks, LVMs and such, it's not even worth comparing!
> However, they can be quite expen$$$ive.

As I understand it, a SAN connects to the server via a 2Gbit link = 500 MB/s.

This is approximately the same as the maximum (theoretical) throughput as 3x160MB/s SCSI controllers.

Why then should a SAN outperform (as has been said to me) a local storage approach?

When I asked, I was told that the SAN had an enormous cache and it was this that was responsible for the performance.

It it me, but having the data cache at the wrong side of a 500MB/s link compared with local memory at GB's/s seems mad.

The response that followed to this statement was: well I would still use a SAN because of ease of administration.

But surely, that's a simple trade off, how much time do I save at c£10,000 per person-month compared with the additional cost of the SAN?

In addition, the SAN bought was some HP thing of 750GB and you have to pay extra licence fees if you go above 1TB (as they want to now), and buy additional cache. It sounds like a licence to print money for the vendor. No wonder they're dead keen on the things. Received on Thu Feb 07 2002 - 22:59:32 CST