Details
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Bug
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Resolution: Fixed
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Minor
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Lustre 2.14.0, Lustre 2.16.1
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None
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3
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9223372036854775807
Description
The "lfs migrate --block FILE" command appears to be broken, since it does not block other processes from modifying a file during migration, and instead returns an error:
$ dd if=/dev/urandom of=/myth/tmp/random bs=1 oflag=sync & $ lfs migrate -c2 --block /myth/tmp/random error: lfs migrate: /myth/tmp/random: file changed: Resource temporarily unavailable $ lfs migrate -c2 --block /myth/tmp/random error: lfs migrate: /myth/tmp/random: file changed: Resource temporarily unavailable
This is likely due to the use of a lease to be notified of the file modification during migration. Previously, "lfs migrate --block" was using a group lock to block other clients from accessing the file during migration.
The "lfs migrate --block" command is important for OST evacuation, because it is the "last resort" mechanism to move files off an OST before it is removed from service. This needs to complete even if there is an application that is writing to the file, though the application writing to the file will block until the migration is complete.
