Hi Lars, I hesitated replying to this post since I'm not sure what fragments-per-cylinder-group stands for, and I don't want to give some bad advice. But the issue just wouldn't exit my mind, so here's what came sprouting up.
Since "The default is to compute the maximum allowed by the other parameters", and you are planning to change some if those other parameters, probably best leave computing the '-c' value to mount_mfs(1). The -m option in your example sets the default value, so you can safely drop that as well. I would simply run mount_mfs() from the commandline and run MAKEDEV in the MFS partition, and experiment with the size value (-s) based on a No News Is Good News approach (no complaints means everything works). You can then try to finding an optimum value for the '-i' option. If the value is too large, running MAKEDEV will result in some "out of inodes" error. If it's too low, you'll be wasting disk space on inode blocks (typically one per 64 inodes). After this you should find free space again, and go back to the previous step. In the end you should be able to come up with a nice balance between these two entities (size/ipb). Probably best leave some space for additional device nodes as well. All this assuming that you really want to squeeze every last byte out of the MFS. Have fun! Bill On Tue, 2008-01-15 at 14:56 +0200, Lars Noodén wrote: > I've got OpenBSD 4.2 on a net4801 and am mounting /dev in RAM. I'd like > to reduce the amount of memory used even further. Currently only %4 is > used: > Filesystem Size Used Avail Capacity Mounted on > mfs:21800 853K 34.0K 777K 4% /dev > > What should I be aware of in /etc/fstab to minimize the memory footprint > of /dev? Currently, I have: > swap /dev mfs rw,-P/dev.base,-i1,-s2300,-c264,-m5,nosuid 0 0 > > Random changes to mfs' parameters aren't getting me anywhere. There > should be a rational way of arriving at optimal settings for mfs: > > -b block-size > -c fragments-per-cylinder-group > -f frag-size > -i bytes > -m free-space > -s size > > Regards, > -Lars > _______________________________________________ > Soekris-tech mailing list > Soekris-tech@lists.soekris.com > http://lists.soekris.com/mailman/listinfo/soekris-tech > -- "What's a computer?" - MES _______________________________________________ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
