Xref: utzoo comp.sys.amiga:38783 comp.sys.amiga.tech:6756 Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!ubc-cs!van-bc! From: lphillips@lpami.wimsey.bc.ca (Larry Phillips) Newsgroups: comp.sys.amiga,comp.sys.amiga.tech Subject: Re: FFS details Message-ID: <704@lpami.wimsey.bc.ca> Date: 17 Aug 89 21:50:31 GMT Lines: 40 Return-Path:To: van-bc!rnews In , cire@dustbin.cisco.com (Eric B. Decker) writes: >2) Where can I find detailed specifications of the FFS? I don't know of anywhere you can find the details offhand, but here are all the differences I know of between the old and new file system. -------------------- Block 0 (Cyl 0, Head 0, Sector 0 on any partition), contains: OFS: 'DOS',0 FFS: 'DOS',1 -------------------- Root block: FFS can have an extension to the bitmap pointer table. The pointer to the next sector containing pointers to bitmap pages is contained in longword $68 -------------------- Hash chain extensions are sorted in increasing order of blocks pointed to. -------------------- File data blocks contain 512 bytes of data, with none of the overhead contained in the OFS scheme. This results in a tradeoff. You trade considerable speed for less recoverability. -------------------- -larry -- "So what the hell are we going to do with a Sun?" - Darlene Phillips - +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+