From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Brett Russ" Subject: % of filesystem using tails/tail unpacking (shred related) Date: Fri, 25 Oct 2002 17:46:14 -0400 Message-ID: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com List-Id: Content-Type: text/plain; charset="us-ascii" To: Reiserfs-List Is there a way to analyze an existing ReiserFS and find out how many of the blocks are tail packed as opposed to full/partially full from the same file? This could lead to an impact study of converting it to an unpacked state. >From the information I have received so far, the only way shredding can reliably work on Reiser, tail packing and data journaling need to be disabled. However, existing filesystems using tail packing can not be simply unpacked to separate blocks without considering the following: 1) as mentioned first, an impact study should be done to determine if unpacking will overflow the available space on the device 2) an unpack routine would need to be written if it doesn't exist. With my current knowledge of Reiser and my timeframe (3 weeks) this is not possible for me to do IMO. 3) the unpack operation would need to treat the previously packed blocks as sensitive by shredding them after all tails were relocated but before returning the block to a free list 4) this operation, depending on the outcome of step 1, would be very expensive in performance That's all I can think of right now. Does this sound accurate? thanks, brett