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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