RE: iSCSI: response to second login (with same ISID)

[Patrick Stirling <pms@veritas.com>]

On Mon, 28 May 2001, Sanjeev Bhagat (TRIPACE/Zoetermeer) wrote:

> Well the conflict of writing to same sector can still be avoided by
> implementaion of some locks in the target but I wonder what will happen in
> this case where 2 inititators are connected to a target.
 
> From: Lakshmi Ramasubramanian [mailto:nramas@windows.microsoft.com]
> 
> Even if the target is capable of supporting multiple initiators, won't
> it cause problems  with devices such as disk - say, filesystem from the
> two initiators' side attempt to write 
> to the same sectors (even not intentionally) would cause data
> corruption. Is iSCSI layer suppose to guard against this type of
> device sharing? 

Umm, am I missing something here?

If 2 initiators want to access the same SCSI device, they must coordinate
to avoid clashing with each other. It's not the device's responsibility to
prevent this. This is one reason several companies have complicated
clustering software.

patrick
Patrick Stirling
VERITAS Software (vendor of complicated clustering software!)