From mboxrd@z Thu Jan 1 00:00:00 1970 To: 9fans@cse.psu.edu From: Poul-Henning Kamp Message-ID: <13905.1043156353@critter.freebsd.dk> Subject: [9fans] On FreeBSD's GEOM Date: Tue, 21 Jan 2003 14:39:13 +0100 Topicbox-Message-UUID: 4490ed5a-eacb-11e9-9e20-41e7f4b1d025 I was made aware that GEOM is being talked about over here and after checking the archive I thought I'd just drop a note with the scoop: GEOM is about transforming disk I/O requests, not about filesystems. Basically it is a modular and stackable framework for doing things like MBR partitioning, BSD disklabel partitioning etc Mirror RAID-5 Striping Encrytion Integrity Multi-Path fail-over. in other words, transformations which operate on the location and/or contents of disk sectors and know nothing about what is actually stored in the sectors and why. I have tried to set a precedent so that on-disk metadata like MBR's and BSD disklabels are read in an architecture independent fashion, and the result of this is that FreeBSD 5.0 on a Sun Sparc64 machine can understand MBR partitioned disk and the IBM PC platform can understand a Solaris disklabel. The most interesting module currently is probably the "GBDE" encryption module which offers very strong encryption at the disk level, targeted at protecting "cold disks", lost laptops, stolen media etc etc. GEOM and GBDE was sponsored by DARPA under the CBOSS program. I gave a tutorial on this at EuroBSDcon2003 (the slides are on their web-page: http://2002.eurobsdcon.org/papers/) And I have offered USENIX to do the same tutorial at BSDcon2003 in september. (I'm not on this list, so make sure I'm in the Cc: if you want me in the loop) Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.