Description of problem: sfdisk does not work with /dev/mapper multipath'ed devices This command does not work: #sfdisk --no-reread /dev/mapper/oraRAC4ART4_disk1_4500M < /root/4500M-partitioning.txt Disk oraRAC4ART4_disk1_4500M: cannot get geometry sfdisk: bad input Now... from the output of multipath -ls: oraRAC4ART4_disk1_4500M (SEMC_____SYMMETRIX______5032630AC000) [size=34 GB][features="0"][hwhandler="0"] _ round-robin 0 [active] _ 1:0:0:20 sdaq 66:160 [active][ready] _ 0:0:0:20 sdn 8:208 [active][ready] Notice /dev/sdn is one of the paths. It works: #sfdisk --no-reread /dev/sdn < /root/4500M-partitioning.txt Successfully wrote the new partition table Re-reading the partition table ... Version-Release number of selected component (if applicable): How reproducible: Every time Steps to Reproduce: 1.See above 2. 3. Actual results: Expected results: Successfully perform sfdisk operations against multi-pathed devices. Additional info: SEG comments on this request: this is a feature, and one I highly doubt will go anywhere but here it goes. Device-mapper devices may describe anything, and may not necessarily have a one-to-one relationship with its underlying device (which is the case with LVM). Multipath happens to be 1 of the many things that utilizes DM, and is the only thing that has a one-to-one relationship with the underlying device. So although it may make sense to use fdisk/sfdisk with dm devices in this particular case, there is an overwhelming number of cases where you don't want this functionality, you would even want to prohibit it. I explained this to Cisco when I was onsite with them.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2008-0751.html