How many chunks will be compressed prior to hashing?

The EMC Avamar client needs to backup a file and has performed sticky-byte factoring.

This results in the following:

– Seven (7) chunks that will compress at 30%

– Four (4) that will compress at 23%

– Two (2) chunks at 50% compression

How many chunks will be compressed prior to hashing?
A . 4
B . 7
C . 9
D . 13

Answer: C

Explanation:

vamar, has a rather nifty technology called Sticky Byte Factoring which allows it to identify the changed information inside a file by breaking the file into variable length objects, this leads to much greater efficiency than fixed size approaches as changes made early in a fixed length sequence affect all subsequent blocks/chunks/objects/whatever in that sequence. This in turn changes all the fingerprints taken following the changed data which means you end up with a lot of new blocks/chunks/objects/ whatever even if the data really hasn’t changed all that much. Sticky Byte Factoring on the other hand can tell what exactly has changed, not just that things have changed.