[LU-4015] Have ldiskfs handle changing device numbers for an external journal

• Type: Improvement
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.6.0, Lustre 2.4.2, Lustre 2.5.1
• Affects Version/s: Lustre 2.4.1, Lustre 2.5.0
• Labels: patch
• Environment: MDT server with a installed RHEL6.4 distro. The MDT uses a external journal.
• Assignee: James Nunez (Inactive)
• Reporter: James A Simmons

Description

For linux the block device name always maps to the UUID but this is not the case for device numbers. Usually this is not a problem but if you use a external journal and after a reboot the device number change will prevent the MDT from mounting. The proper solution is to add a mount option for ldiskfs to locate the journal using the device path instead of the device number.