A disruptive chunkd on-disk file format change was just pushed to
hail.git. It is a minor format update, but it is incompatible. chunkd
v0.8+ objects are now binary-incompatible with the just-released chunkd
v0.7.
The update adds a magic number and object size to the on-disk object
header (struct be_fs_obj_hdr), plus some reserved space for future
additions.
The magic number and object size add easy (and CPU-inexpensive) sanity
checks to the object I/O code. The object size field is largely
redundant, intended mainly for disaster recovery. However, storing the
object size enables the file format to support multiple objects inside a
single POSIX filesystem file.
Hopefully this means implementing an APPEND operation in chunkd is now
feasible. But if APPEND falls through, these two new be_fs_obj_hdr
members retain some utility anyway.
Jeff
--
To unsubscribe from this list: send the line "unsubscribe hail-devel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
