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15 May 18 21:58
Join Date: 31 Dec 2014
Posts To This List: 51
Windows dedupe and volume filter
I have a driver that updates a bitmap file on the volume to indicate changed
blocks. I bypass the FS when updating the clusters so that I do not get a
deadlock going through the FS. This driver works exceptionally well until
Windows Deduplication is enabled. It appears that the clusters occupied by my
bitmap are being moved. This results in me overwriting random data that may not
be in the location where my retrieval pointes used to say were owned by the
When I open the file, I send control to FS to lock the clusters in place. This
was added to prevent defrag from moving my data. I would assume that locking
these clusters would also prevent deduplication from moving the clusters.
Apparently, it does not.
I am looking for a way around this issue. Is there a way to prevent a file from
being subject to deduplication? It seems that the MS deduplication is a little
lacking in third party APIs.
Any help would be appreciated.