Details
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Technical task
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Resolution: Done
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Minor
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None
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None
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None
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9223372036854775807
Description
Soon after it mounts a file system a client will ask for a sequence of file IDs to be preassigned to it. This fosters an efficiency in that it doesn't need to wait for the FID to be assigned at the time it needs it and it can get many at once.
This is done in a "lazy" way in that the client does not issue the request until the first time it needs a FID. The PtlRPC SEQ_QUERY accomplishes this. The MDT returns a FID sequence number, which is a 64 bit unsigned that acts as the first half of any of the FID's in the sequence. The second half is the object ID (32 bits) and the version (32 bits) as documented in lustre/include/lustre/lustre_user.h in the "struct lu_fid".
Expand on the above and incorporate it into the file_id.txt portion of the protocol document.