[Gllug] Filesystems again :)

[John Hearns]

On Thu, 2002-05-16 at 15:26, rich at annexia.org wrote:
> On Thu, May 16, 2002 at 12:53:31PM +0200, John Hearns wrote:
> > On Thu, 2002-05-16 at 11:37, pauln at truemesh.com wrote:

> Was this on Linux? What software was he using for the
> replication? We are running some very large arrays here
> using Linux / ext3, and I'd love to be able to replicate
> them easily.
> 
Sorry - my last post was a bit of a ramble.

Given that the speaker I referred to was from Compaq,
a lot of his talk was 'roadmapping' and trying to
reassure people that product lines would not disappear
after the merger etc.

Anyway, back to interesting things.
Storage virtualization is the latest buzzword in that industry.
The idea is that your server reads/writes data,
via SCSI or fibre channel, as normal, using the normal file
systems it is used to.
The storage array itself is however intercepting these reads/writes,
and not putting them onto the array in the file system layout.
Your server does not know which physical devices any data is going onto.
Rather, the storage array writes blocks of data,
and keeps a table of pointers to where the data resides.
So, for instance, to take a snapshot all you do is copy the
pointer table.
(The array takes care of any block of data which changes by
now keeping the "before" image of that block in a special area)



http://www.infoworld.com/articles/fe/xml/01/10/15/011015festorage.xml



-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug