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kot_linuxoid

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what happens after removing a lun from lvm under linux

Hi:

     We have been undergoing some disk problems on a type 6 raid.
     We have 4 luns and want to move the data to another lun. Then remove
     the problematic lun.
     This is run under Centos 5.3 and the 4 luns are grouped together by lvm.
     We added lun5 and put it under the lvm so linux now sees
     5 devices /dev/dm-0 through /dev/dm-4. I added /dev/dm-4 to the volume group.
    And am currently running pvmove. to move the extents from the problematic pv. (dm-1).

   The question is after I remove dm-1 from the volume group and then remove the lun
   will I have problems recognizing my data.

   The reason I ask is that normally linux may see the following disks:
  /dev/sda, /dev/sdb. /dev/sdc. When /dev/sdb is removed /dev/sdc will become
  /dev/sdb on a rescan. So I was wondering if I will see the same problems here.

  I have
    1 - luns, 2 - multipath mapping, and 3 - lvm.

  Thank you for your help.
   
           
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Avatar of jmslagle
jmslagle
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kot_linuxoid

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thank  you very much.
He answered my concerns, and I knew that the
multipath drivers depend on a wwid to map.
So I didn't need info on the multipath. But to have been complete referring to the multipath(s) should
have been discussed as well.

In either case thanks to imslagle for his answer.