From owner-freebsd-current Wed Jun 3 03:43:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA17016 for freebsd-current-outgoing; Wed, 3 Jun 1998 03:43:05 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from kremvax.demos.su (kremvax.demos.su [194.87.0.20]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id DAA17006 for ; Wed, 3 Jun 1998 03:43:00 -0700 (PDT) (envelope-from sinbin.demos.su!bag@kremvax.demos.su) Received: by kremvax.demos.su (8.6.13/D) from 0@sinbin.demos.su [194.87.5.31] with ESMTP id OAA02451; Wed, 3 Jun 1998 14:37:47 +0400 Received: by sinbin.demos.su id OAA27314; (8.6.12/D) Wed, 3 Jun 1998 14:36:57 +0400 From: bag@sinbin.demos.su (Alex G. Bulushev) Message-Id: <199806031036.OAA27314@sinbin.demos.su> Subject: Re: I see one major problem with DEVFS... In-Reply-To: <199806030915.NAA15706@sinbin.demos.su> from "Alex G. Bulushev" at "Jun 3, 98 01:15:14 pm" X-ELM-OSV: (Our standard violations) no-mime=1; no-hdr-encoding=1 To: bag@sinbin.demos.su (Alex G. Bulushev) Date: Wed, 3 Jun 1998 14:36:57 +0400 (MSD) Cc: mike@smith.net.au, tlambert@primenet.com, eivind@yes.no, sepotvin@videotron.ca, current@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL32 (25)] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > on nfs client we have: > > {nfs_clnt1}# mount > /dev/sd0s1a on / (local, noatime, writes: sync 6436172 async 3495235)) > procfs on /proc (local) > nfs_srv:/mnt/roots on /mnt/roots > {nfs_clnt1}# ls -al /mnt/roots/VM1/dev/null > crw-rw-rw- 1 root weel 2, 2 3 jun 14:27 /mnt/roots/VM1/dev/null > ^^^^^^^^^^^ time from nfs_srv > {nfs_clnt1}# chroot /mnt/roots/VM1 /bin/cat /etc/passwd > /dev/null sorry, correct demonstration is: {nfs_clnt1}# ls -al /mnt/roots/VM1/dev/null crw-rw-rw- 1 root wheel 2, 2 3 jun 14:27 /mnt/roots/VM1/dev/null {nfs_clnt1}# chroot /mnt/roots/VM1 /bin/sh # /bin/cat /etc/passwd > /dev/null # exit {nfs_clnt1}# ls -al /mnt/roots/VM1/dev/null crw-rw-rw- 1 root wheel 2, 2 3 jun 14:28 /mnt/roots/VM1/dev/null ^^^^^^^^^^^ time changed {nfs_clnt1}# ls -al /dev/null crw-rw-rw- 1 root wheel 2, 2 3 jun 14:28 /dev/null ^^^^^^^^^^^ time changed {nfs_clnt1}# > > > so we use "nfs mounted devices" localy on nfs clients > surely local major/minor for devices mast by the same as on the remote server > or u mast use device proxy on fs level (not existing now) > > with "classic" device nodes on file systems it is realy simple > to use this scheme > > with dynamic device id and devices only on devfs mounted, it is very hard > to use devices on nfs, especially if u have several nfs clients vith handreds > of chrooted "virtual mashines", a lot of mount/unmont devfs and rm/mknod in > boot time and before/after of delete/create each VM and on each nfs > server/client kill u system and require a number of custom scripts and > sync of all manipulation via network (using rsh or other tools) > > > > > > For normal devices that are only operated on via open/close/read/write, > > > it makes sens to export a devfs. > > > > No, it does not. There is no identifying information exported with a > > DEVFS node that allows the local system to correctly connect a node > > from a remote DEVFS (which may not map to a local driver) to a local > > device. > > > > > This isn't as useful as the true proxy provided by OpenNET, but it's > > > a good step in that direction. > > > > You want to proxy device accesses to devices on the exporting system. > > That's a completely different kettle of fish entirely. > > > > -- > > \\ Sometimes you're ahead, \\ Mike Smith > > \\ sometimes you're behind. \\ mike@smith.net.au > > \\ The race is long, and in the \\ msmith@freebsd.org > > \\ end it's only with yourself. \\ msmith@cdrom.com > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-current" in the body of the message > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message