10-13-2014 05:46 AM
Hi,
Disk mirroring as described in IOS XR Fundamentals:
"At the time of writing this book, disk mirroring is supported only between disk0: and disk1: on both CRS-1 and c12000 platforms. Disk mirroring works by replicating critical data from the primary boot device onto another storage device on the same RP. This other storage device can be referred to as a
mirrored disk or simply as a secondary device. If the primary boot device fails, applications continue to be serviced transparently by the secondary device, thereby avoiding a switchover to the standby RP. The failed primary storage device can be replaced or repaired without disruption of service."
By now, disk mirroring is also supported on ASR9000 platform:
http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-2/system_management/configuration/guide/b_sysman_cg42asr9k/b_sysman_cg42asr9k_chapter_0100.html
Sam and Xander have commented that disk mirroring on ASR9000 doesn't make much sense as the disk themselves are not field replaceable.
For example: if RSP0/disk0 goes faulty, RSP0/disk1 takes over and a RSP switchover was prevented. Nonetheless, we will have to replace RSP0/disk0 eventually, so all we did with disk mirroring is postpone the maintenance action. Or am I missing something?
What about the CRS platform? Is the situation there the same or are disks field repleacable?
Thank you and kind regards,
Karlo.