Date: Thu, 27 Jan 2000 08:37:08 +1030 From: Greg Lehey <grog@lemis.com> To: Mike Wade <mwade@cdc.net> Cc: "Jeffrey S. Sharp" <jss@subatomix.com>, freebsd-small <freebsd-small@freebsd.org> Subject: Mounting flash file systems (was: your mail) Message-ID: <20000127083708.A44457@freebie.lemis.com> In-Reply-To: <Pine.GSO.4.10.10001260957410.4247-100000@server2> References: <002201bf67c6$f76b4090$0dea5e18@mmcable.com> <Pine.GSO.4.10.10001260957410.4247-100000@server2>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wednesday, 26 January 2000 at 10:03:08 -0500, Mike Wade wrote: > On 26 Jan 2000, Jeffrey S. Sharp wrote: > >> Therefore, I suggest something like what Warner has done (and that I am >> working on as time permits), where the flash is the root fs and /tmp, >> /var, and so on are mounted as small MFS filesystems. The flash is >> normally kept mounted read-only. Then, instead of running an update >> script, one simply remounts the flash read-write, makes changes, and >> remounts read-only. > > I've attempted this and I ended up with a filesystem of corrupted files > when mounting read-only, remounting read-write, then remounting read-only > several times. I ended up partitioning the flash and creating a read-only > binary partition and a read/write config partition that is mounted only on > update. > >> From the mount man page: > > BUGS > It is possible for a corrupted file system to cause a crash. > Switching a filesystem back and forth between asynchronous and normal > operation or between read/write and read/only access using ``mount > -u'' may gradually bring about severe filesystem corruption. This doesn't fit. You didn't say you were changing your file systems between synchronous and asynchronous. That's the key of this particular problem. > It would be very nice to have this feature when dealing with flash. > Also it would be nice to have a "accidental power off" safe file > system when using hard drives for embedded devices such as Internet > Appliances. I still think that a R/O file system would beat any of these. If you have to mount R/W, leave it that way until reboot. Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000127083708.A44457>