Heinz-Josef Claes wrote (ao): > Am Dienstag, 28. April 2009 19:38:24 schrieb Chris Mason: > > On Tue, 2009-04-28 at 19:34 +0200, Thomas Glanzmann wrote: > > > Hello, > > > > > > > I wouldn't rely on crc32: it is not a strong hash, > > > > Such deduplication can lead to various problems, > > > > including security ones. > > > > > > sure thing, did you think of replacing crc32 with sha1 or md5, is this > > > even possible (is there enough space reserved so that the change can be > > > done without changing the filesystem layout) at the moment with btrfs? > > > > It is possible, there's room in the metadata for about about 4k of > > checksum for each 4k of data. The initial btrfs code used sha256, but > > the real limiting factor is the CPU time used. > > > > -chris > > > It's not only cpu time, it's also memory. You need 32 byte for each 4k block. > It needs to be in RAM for performance reason.
Less so with SSD I would assume. -- Humilis IT Services and Solutions http://www.humilis.net -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
