Re: [Scst-devel] How does SCST handle a backend storage array disconnect

[Bart V. A. <bva...@ac...>]

On Tue, Jan 31, 2012 at 3:53 PM, matthew patton <pat...@ya...> wrote:

> <quote>
> That should allow to delete the sd
> device via sysfs without having to take down the SCST vdev. Also, the
> device mapper can be configured to block SCSI commands as long as no
> underlying sd device is available to send SCSI commands to.
> </quote>
>
> Do tell, how? I haven't seen this done before nor did I know it was even
> possible. I don't think I've seen anything remotely relevant in the man
> pages.
>

You have a point. I've been looking around in the kernel tree for
documentation about this but haven't found any. Apparently this feature
already exists considerable time - at least since kernel 2.6.12.

Via a search engine I found several documents in which it is explained how
to remove a SCSI device via sysfs (search for the text "/delete" in this
document if you do not want to read these documents entirely):
http://www.ibm.com/developerworks/wikis/display/LinuxP/SCSI+-+Hot+add,+remove,+rescan+of+SCSI+devices
http://gurkulindia.com/main/2011/05/linux-dynamically-addremove-scsi-from-linux/

Bart.