From owner-freebsd-fs Sat Jan 31 09:25:48 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA07499 for freebsd-fs-outgoing; Sat, 31 Jan 1998 09:25:48 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from x115-105.reshalls.umn.edu (x115-105.reshalls.umn.edu [134.84.115.105]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA07469; Sat, 31 Jan 1998 09:25:36 -0800 (PST) (envelope-from chris@x115-105.reshalls.umn.edu) Received: from x115-105.reshalls.umn.edu (localhost [127.0.0.1]) by x115-105.reshalls.umn.edu (8.8.7/8.8.7) with ESMTP id LAA13881; Sat, 31 Jan 1998 11:27:19 -0600 (CST) (envelope-from chris@x115-105.reshalls.umn.edu) Message-Id: <199801311727.LAA13881@x115-105.reshalls.umn.edu> From: mikk0022@maroon.tc.umn.edu To: "Alton, Matthew" cc: fs@FreeBSD.ORG, hackers@FreeBSD.ORG Subject: Re: Filesystem hacking In-reply-to: Your message of "Fri, 30 Jan 1998 14:52:27 CST." <31B3F0BF1C40D11192A700805FD48BF9C33287@STLABCEXG011> References: <31B3F0BF1C40D11192A700805FD48BF9C33287@STLABCEXG011> Date: Sat, 31 Jan 1998 11:27:19 -0600 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org X-To-Unsubscribe: mail to majordomo@FreeBSD.org "unsubscribe freebsd-fs" On Fri, 30 Jan 1998 14:52:27 -0600 "Alton, Matthew" wrote >I have decided to code up an IBM-style journaling filesystem >(jfs) with maximum portability for free unices. While I'm at it >I had might as well have the clean-bits map to a PP/extent >disk arrangement which will act as a useful abstraction for a >Logical Volume Manager / Veritas -esque disk management >system which I also find interesting enough to code up. What do you know about LFS for FreeBSD. I haven't used it, but from what I understand, it was an early implementation of a "log-structured filesystem" for BSD. Are "log-structured" and "journaling" synonymous? I know that SGI's XFS is a hybrid, where each filesystem has a log which stores committed operations on the filesystem. The filesystem is a fairly normal filesystem from what I understand. The advantage to the separate log is flexibility -- some installations store the log on a separate, high speed disk, but most just use an "internal log" on the same partition as the filesystem. As far as Logical Volume Management, SGI's XLV is a good target (can you tell what kind of UNIXen I use at work yet? :-). In my understanding, the system marks each disk with its place in the volume, so the logical volume can be automagically composed on boot-up. This is nice, because there is no configuration file to worry about, and you can move around the disks on the SCSI chain without affecting the volume. >This is not an attempt to morph FreeBSD into AIX by any >means. I have zero real experience with AIX, but know enough to thank you kindly for this :-) Sorry 'bout going on about SGI. I'm really not a salesman, just a not-very-annoyed user tossing out ideas.... :-) I like the idea of implementing multiple filesystems on FreeBSD. I have a currently unused disk, if you'd like a beta tester (hint, hint... :-) -- Chris Mikkelson mikk0022@maroon.tc.umn.edu U of M Tuba and Student "Life is too short for windows..." '94-present