Details
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Improvement
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Resolution: Fixed
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Minor
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None
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9223372036854775807
Description
during Lustre server startup few small files need to be updated (e.g. config backup).
at this point buddy/bitmap cache is empty but mballoc wants to find a big chunk of free space for group preallocation and reads bitmaps one by one.
sometimes this can take a very long time.
one possisble workaround is to disable preallocation during mount.
a long term plan is to limit scanning and prefetch bitmaps, but this needs more efforts and will be tracked separately (LU-12970)
