Red Hat Bugzilla – Bug 466616
[NetApp 5.5 feat] mkinitrd doesn't support changing root volume from non-multipath to multipath configuration.
Last modified: 2009-10-27 15:15:41 EDT
Description of problem: mkinitrd shipped with RHEL5.2 doesn't support changing root volume which is on iscsi lun to multipathed device. This creates a problem when one has installed root on iscsi lun and as multiple paths to the lun are now available, he wants to move root to multipathed iscsi device.(eg. from /dev/sda to /dev/mapper/mpath0). mkinitrd is expected to change initrd image,grub parameters and fstab entry. Version-Release number of selected component (if applicable): mkinitrd-5.1.19.6-28 How reproducible: very reproducible Steps to Reproduce: 1.Finish SANboot(root on iscsi lun) installtion. 2. you will see df output something like this. /dev/sda3 7632880 3298568 3940320 46% / 3.Here sda is a iscsi device. 4.Enable more than one paths to the same lun. 5.Configure multipath. 6.Execute mkinitrd with multipath module include option. Actual results: mkinitrd will only include multipath modules in initrd. If you reboot system, you won't see any difference. Root will still be on iscsi lun and not on multipathed device. Expected results: mkinitrd should change initrd in such a way that, on next reboot root should be on multipathed device. Additional info: This can be taken as feature request. SUSE does provide this support. There, if you run 'mkinird -f mpath', root does get shift to multipathed device.
Moving to RHEL 5.5 so it doesn't get mistakenly closed by the bot
In RHEL6, dracut will be able to handle the change from single path to multipath iscsi (possibly without even needing to rebuild the initrd). However, it is not appropriate for either it or mkinitrd to change grub parameters and/or fstab entries. When someone changes a storage configuration they should update fstab and grub themselves. Maybe we can add some *separate* tool to help them with this,but modifying these files is well outside the design center for mkinitrd / dracut.