How to remove scsi san disk?

[Ryan Golhar]

I was able to remove /dev/sdb and /dev/sdc.  I even went so far as to 
remove the mapping from the SAN, rebooted and only the native hd is 
picked up at /dev/sda.

I re-mapped a 500GB parition to this particular host...there is only one 
fibre-channel card plugged in, the second one isn't used yet.  When I 
rebooted/rescanned for drives, both /dev/sdb and /dev/sdc are picked up.

/dev/sdc is recognized as the 500GB parition, but linux can't read 
/dev/sdb.  What is this and where is it coming from?  I'm not using 
multipathing as far as I'm aware of.

oh the SAN is a Sun StorageTek 2540.

Ryan


Ray Van Dolson wrote:
> On Fri, Apr 17, 2009 at 10:06:49AM -0700, Ryan Golhar wrote:
>> How do I determine the device mapping of a SCSI drive to the SCSI host, 
>> bus, lun?  And  How to I remove the mapping to delete the SCSI drive?
>>
>> I have a fibre-connected SAN.  I've created a few drives on the SAN and 
>> mapped it to my linux host.  The linux host sees the drives just fine. 
>> I remove the drives from linux, and left them as uninitialize disks. 
>> Whenever I run "fdisk -l", I get output:
>>
>> [root at cicweb1 tmp]# /sbin/fdisk -l
>>
>> Disk /dev/sda: 440.0 GB, 440076861440 bytes
>> 255 heads, 63 sectors/track, 53502 cylinders
>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>
>>     Device Boot      Start         End      Blocks   Id  System
>> /dev/sda1   *           1          13      104391   83  Linux
>> /dev/sda2              14       53502   429650392+  8e  Linux LVM
>>
> 
> This might help:
> 
>   http://kbase.redhat.com/faq/docs/DOC-3942
> 
> I typically use /proc/scsi/scsi or lsscsi to list the devices and
> figure out which ones I want to remove, then use the appropriate
> command to remove the device.
> 
>> I also get in /var/log/messages that drives that I since removed from 
>> the SAN.  How to I remove these (/dev/sdb and /dev/sdc) in linux?
> 
> <snip>
> 
> I wonder if you have multipathing set up?  The failover path often will
> show up as an invalid or unavailable drive.
> 
> This usually can be fixed by setting the correct multipath device
> settings in your /etc/multipath.conf config file.
> 
> Ray
>