From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <86hbcrfawn.fsf@cmarib.ramside> References: <81c92a8342f74040cbdf11041c77e511@quintile.net> <86hbcrfawn.fsf@cmarib.ramside> Date: Sat, 29 Jan 2011 20:07:56 -0800 Message-ID: From: John Floren To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [9fans] HELP: recoving important header file rudely clobbered by mk Topicbox-Message-UUID: a4231e7c-ead6-11e9-9d60-3106f5b1d025 On Sat, Jan 29, 2011 at 5:16 PM, wrote: > "Steve Simon" writes: > >> is this native plan9, p9p, or 9vx? > > I'm running the stock 386 distribution, on a real hard drive on real > hardware. =A0I figured learning a new OS would be simpler without having > to think about what's virtual versus what's real, versus what's Linux. > >> do you definitely have fossil and venti running? > > I have no idea. =A0I just chose the default installation options, > installing from the CD following the install instructions. =A0As far as I > know, "Venti" is a volcano in Italy. > In that case, you'll only have Fossil installed. >> a missing archive/main looks like you don't >> have archival dumps enabled in fossil.conf? > > Oops, s|archive/main|main/archive| > >> perhaps you have snapshots enabled? > > I know I have "fossil". =A0I didn't know "dump" and "snapshots" were two > different things. =A0Are there any docs that describe these file systems > in language a newbie has a snowball's chance in Inferno of > understanding? =A0The man pages for Plan 9 file systems all seem rather > opaque... i.e., "cached-worm file system"? > Fossil is the "front-end" filesystem. You can run it alone. It can be configured to take snapshots at regular intervals (I like every 15 minutes, check the fossilcons man page for how to set it up) which eventually (typically after a few days) expire and are cleared. Venti is the archival storage; if Venti is present, Fossil will try to make an archival dump to Venti every morning. The dump is basically a snapshot, except it's permanent. One side effect is that when a dump happens, data on Fossil gets replaced with a pointer to a block in Venti, clearing up your Fossil partition. For that reason, I typically only allocate a few gigabytes to Fossil and all the rest of the disk to Venti. The cached-worm filesystem, cwfs, is related to the old filesystem. The same goes for "fs" (in many cases, for example the man page fs(4)), "cwfs", "worm", "kfs", or "kenfs". Erik Quanstrom still uses kenfs, and based on his positive experiences with it some others have been experimenting with it as well. However, kenfs requires its own dedicated machine and is a bit tougher to set up. I've continually meant to write some sort of beginners-level summary of the system including things like Fossil and Venti, but the magnitude of the task is daunting. I may try to do a more clear description of how the filesystems work together in the near future. >> what happens if you run 9fs snap? > > The mount succeeds, but /n/snap is empty. > I don't remember for sure, but it's possible that Fossil doesn't get configured to take snapshots when Venti isn't installed, for space reasons. If you can run "fossil/conf /dev/sdC0/fossil" and post the results here, we'll be able to tell, or you can run the command and examine the results for yourself based on the fossilcons man page. If you haven't spent too much time configuring your system, or put too much on it that cannot be backed up, and if you have a large enough disk (20 GB should be plenty unless you're storing large files or music/video), you might want to try re-installing and choosing the fossil+venti option. This will give you the archival dump storage, which can be really nice. John