Liane Praza's Weblog

I'm still delinquent on a number of smf(5) entries. But, here's a quick one that's at least smf(5)-related. Based on a few pieces of internal mail, it seems like lots of folks out there are asking about the new filesystems that appeared on Solaris 10 when they typed mount. An excerpt from one of my systems:

/ on /dev/dsk/c1d0s0 read/write/setuid/devices/intr/largefiles/logging/xattr/onerror=panic/dev=1980040 ...
/devices on /devices read/write/setuid/devices/dev=4380000 on Fri Feb  4 19:29:50 2005
/system/contract on ctfs read/write/setuid/devices/dev=43c0001 on Fri Feb  4 19:29:50 2005
/proc on proc read/write/setuid/devices/dev=4400000 on Fri Feb  4 19:29:50 2005
/etc/mnttab on mnttab read/write/setuid/devices/dev=4440001 on Fri Feb  4 19:29:50 2005
/etc/svc/volatile on swap read/write/setuid/devices/xattr/dev=4480001 on Fri Feb  4 19:29:50 2005
/system/object on objfs read/write/setuid/devices/dev=44c0001 on Fri Feb  4 19:29:50 2005
/lib/libc.so.1 on /usr/lib/libc/libc_hwcap2.so.1 read/write/setuid/devices/dev=1980040 on Fri ...
/dev/fd on fd read/write/setuid/devices/dev=4680001 on Fri Feb  4 19:29:58 2005
/tmp on swap read/write/setuid/devices/xattr/dev=4480002 on Fri Feb  4 19:29:59 2005
/var/run on swap read/write/setuid/devices/xattr/dev=4480003 on Fri Feb  4 19:29:59 2005

Most of the new mounts we've added this release are dynamic filesystems which reflect kernel state. These include ctfs(7FS) (used extensively by smf(5)) and objfs(7FS). Like procfs, they're truly dynamic and are generated by the kernel on each boot. There's no need to include them in system backups.

The libc loopback mount is pretty nifty. Once Solaris has booted far enough, it looks at the hardware capabilities of the system, including what instruction sets it supports. Then it loopback mounts a customized libc which can take advantage of all the performance of the specific chip we're using (if such a customized library is available). Right now, we use this on a set of x86 and x64 systems. See moe(1) for more info on the $HWCAP capabilities. Darren also talks about this in more detail.

devfs(7FS) makes the /devices namespace fully dynamic. If you aren't doing things like using chmod(1) to change device permissions, there's no need to back it up either. Recovery to a new system will be easier if you don't back it up. You can use /etc/minor_perm to specify device permissions without using chmod. See add_drv(1M) for more details.