> In response to a post on data purging Tim Gorman wrote "some on SAN-based > disk, some on NAS-based storage". > > Can someone please explain the differences between these technologies > please. > > My understanding that a SAN is a group of disks which are available on a > network and are not 'owned' by a server and have no direct cables into a > server. > I also understood NAS to be network based disk (duh!)
Please correct, clarify, or comment as needed; I don't recall ever having seen a formal definition for either acronym: * SAN (storage area network): storage-arrays connected by dedicated high-speed interconnects (i.e. SCSI, SSA, FC-AL, etc) managed by a dedicated server, including switches and routers to provide storage for one or multiple storage clients (i.e. what we tend to call "servers")... * NAS (network-attached storage): storage that is hosted by (i.e. mounted on) a dedicated, special-purpose server and made available to network clients via IP protocols like NFS, Samba, etc across general-purpose IP networks. For NAS, think "dedicated NFS server" or "dedicated file server" or the like and you've got the idea... There are so many technologies mixed into SANs that I find it difficult to generalize. It is probably more appropriate to define NAS first and then say "SANs are everything else" in networked storage, but I thought I'd try it the hard way... Further generalizing: * SANs are capable of faster and more sustainable I/O throughput rates, but more complex and more expensive * NAS are economical, easy to administer, and easy to implement, but provide lower sustained I/O throughput rates For this reason, I don't see the question as an "either-or" proposition (i.e. either all SAN or all NAS). They are each point-solutions along a continuum, as illustrated in the "strategy" in my previous reply. Data passes through a life-cycle, just like anything else. Requirements for storage and retrieval can change during that life-cycle... ----- ... "continuum" ...... there's a high-class word I've been itching to use ..... has the potential to become as hoity-toity and annoying as "paradigm" and "juxtaposition", though... :-) > > Thanks > > > John > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Tim Gorman INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).