SnapMirror initialize fails with Error in snapdiff Input output error

Applies to

Issue

• Initializing SnapMirror relationship fails with an error "Transfer failed. (Error in snapdiff (Input/output error)"
• SNAPMIRROR-AUDIT-LOG-TXT.GZ in destination indicates error

Initialize [<TIMESTAMP>]: <UUID> Operation-Uuid=<UUID> Group=none Operation-Cookie=0 action=Start source=<SOURCE_PATH> destination=<DESTINATION_PATH>
Initialize [<TIMESTAMP>]: <UUID> Operation-Uuid=<UUID> Group=none Operation-Cookie=0 action=End source=<SOURCE_PATH> destination=<DESTINATION_PATH> status=Failure message=Transfer failed.(Error in snapdiff(Input/output error))

• Recreating the relationship to new destination volume fails with the same error
• EMS-LOG-FILE.GZ in source indicates that snapdiff.abnormal.abort is detected against source volume during initialzation

[<NODE>: wafl_exempt05: wafl.msg.abnormal.abort:debug]: params: {'vvolname': '<SOURCE_VOLUME>', 'fsid': '1026', 'base_snap_id': '-1', 'incr_snap_id': '279', 'object_id': '4294967295', 'error_in_file': 'prod/common/wafl/wafl_snap.c', 'error_at_line': '434', 'error_msg': 'WSR: Container file :  offset=1488628760576 length=262144, wafl_read_iovec encountered error (status=5)', 'client_uuid': '<UUID>'}
[<NODE>: sd_main: snapdiff.abnormal.abort:debug]: Encountered unexpected error while computing differences between Snapshot copies.

• Event wafl.inconsistent.vol:error is reported in source volume in some cases

Note: wafl.inconsistent.vol:error is not detected unless the problematic block is accessed by client

• PUTs/GETs works fine for the source volume's aggregate without any drops, when checked using "object-store profiler"