| Jim,
There are a number of reasons that the number of blocks in an output
saveset could be different from an input saveset:
1) In the case of multi-volume savesets, each volume starts with a
summary record, and ends with an XOR record (even for an incomplete XOR
group). When putting multiple input volumes onto fewer output volumes,
it's normal for the output saveset to be 1-2 blocks/volume shorter.
Note that this applies to a normal copy, but not a copy/identical.
2) The number of blocks will also change if you change the block size
or group size.
3) Often, especially on older media, there will be rewritten blocks in
the saveset. When the saveset was originally written, blocks might
have returned a write error, and been rewritten by backup. If these
blocks were then found to be readable by SSM they would be ignored, but
would still increment the "blocks read" count. SSM generates an
informational message when it encounters a rewritten block.
Steve
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