Re: scsiadd - lets you add and remove scsi devices on the fly
On Wed, 29 Nov 2000, Paul Slootman wrote:
> On Tue 28 Nov 2000, Cristian Ionescu-Idbohrn wrote:
> >
> > http://llg.cubic.org/misc/
> >
> > I know, there are other ways to do it, but this is the easiest I know
> > of.
>
> The reasoning behind part of scsiadd is flawed; from the README:
>
> : An example: Two hard disks are currently managed by the Linux SCSI system.
> : This corresponds to the following mapping:
> :
> : SCSI ID 0 -> /dev/sd0
> : SCSI ID 2 -> /dev/sd1
> :
> : Now we add a third drive with ID 1. The Linux kernel will remap its
> : devices:
> :
> : SCSI ID 0 -> /dev/sd0
> : SCSI ID 1 -> /dev/sd1
> : SCSI ID 2 -> /dev/sd2
> :
> : You see, that the hard disk with SCSI ID 2 has changed its device (from
> : sd1 to sd2). As other parts of the kernel have not notices this, you are
> : likely to damage both disks /dev/sd1 and /dev/sd2 when reading/writing
> : from them!!!
>
> In fact, the "new" disk with ID 1 will be mapped to the _third_ disk,
> i.e. /dev/sdc, not /dev/sdb (why he uses sd0 etc. isn't quite clear to me).
> There is only a "problem" when rebooting with ID 1 powered on.
Agreed. But, confusing (bad) documentation does not make the tool _less_
useful.
Certain amount of knowledge (like in very many other cases) is obviously
required.
Cheers,
Cristian
--
Be careful, life will kill you.
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