SCSI and SAN

Sharad Chandra sharadc at in.niksun.com
Fri Oct 5 06:01:18 PDT 2007


On Friday 05 October 2007 5:25 pm, Eric Anderson wrote:
> Sharad Chandra wrote:
>  > On Thursday 04 October 2007 6:51 pm, Eric Anderson wrote:
>  >> Sharad Chandra wrote:
>  >>> Hello,
>  >>>
>  >>> 	How to distinguish if /dev/da* devices are internal scsi drivers
>
> or LUNs
>
>  >>> of external SAN?
>  >>
>  >> camcontrol devlist -v
>  >>
>  >> Might help you..
>  >>
>  >> Eric
> >
> > Yes, right by analyzing camcontrol devlist it can be told, but i guess
> > not always.
> >
> > [root at qa7 ~]# camcontrol devlist
> > <IFT A16F-G2422 348C>              at scbus0 target 0 lun 0 (da0,pass0)
> > <IFT A16F-G2422 348C>              at scbus0 target 0 lun 1 (da1,pass1)
> > <IFT A16F-G2422 348C>              at scbus0 target 0 lun 2 (da2,pass2)
> > <IFT A16F-G2422 348C>              at scbus0 target 0 lun 3 (da3,pass3)
> >
> > Here luns are increasing, so it is SAN confirmed by tool. Now my point is
> > if i have a SAN of less than 1TB and i make only 1 LUN. what should be
> > output? guessing: similar to
> > <IFT A16F-G2422 348C>              at scbus0 target 0 lun 0 (da0,pass0)
> >
> > Then it will be difficult to tell, whether it is regular SCSI drives or
> > SAN. Then we need a tool that can tell this da0 belongs to SAN/SCSI or
> > not
>
> Notice the -v to camcontrol.  It will tell you which controller the
> device belongs to, and the controller will help you determine whether it
> is connected to a SAN or not.

[root at qa7 ~]# camcontrol devlist -v
scbus0 on isp0 bus 0:
<IFT A16F-G2422 348C>              at scbus0 target 0 lun 0 (da0,pass0)
<IFT A16F-G2422 348C>              at scbus0 target 0 lun 1 (da1,pass1)
<IFT A16F-G2422 348C>              at scbus0 target 0 lun 2 (da2,pass2)
<IFT A16F-G2422 348C>              at scbus0 target 0 lun 3 (da3,pass3)
<  >                               at scbus0 target -1 lun -1 ()
scbus-1 on xpt0 bus 0:
<  >                               at scbus-1 target -1 lun -1 (xpt0)

Does it?

>
> Other than that, I'm not sure of the distinction that could be made
> between the devices whether it is on a SAN or not.  It could be a
> directly connected fiber channel device, in which case, it isn't quite a
> SAN, yet the FreeBSD system doesn't know (or care) how it's connected.
>
> Eric


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