System Operation

                                              Taos handles many aspects of system operation differently than Ultrix. This has little effect on normal user programs, but does mean that most of the programs documented in Section 8 of the Ultrix Programmer's Manual won't run on Taos. (For Taos analogues, see backup_ff(1), cron(1), df(1), expandpath(1), homeserver(1), lpr(1), mailq(1), pwd(1), restore_ff(1), servername(1), setpgrpme(1), stripcp(1), automount(8), cleardisks(8), crontab(8), dismount(8), givevm(8), installboot(8), mkinit(8), sendmail(8), setconfigurationparameter(8), startrfs(8), tsh(n), and The Firefly Companion.)

    The Taos file flushing daemon runs every 60 seconds and doesn't flush changes to file access times, whereas the analogous Ultrix update system operation command runs every 30 seconds and flushes all attributes including file access times.

    On Taos, there are no block devices or raw disk devices; the mount and umount kernel calls always raise SIGSYS. Analogous facilities are available through the OSFriends interface (see Appendix A.5, page ).

    On Taos, there is no /dev/kmem or /dev/mem file; see instead the OS.GetProcessInfo procedure described in Section 5.5.

  On Taos, the swapon kernel call always raises SIGSYS; VMFriends.Donate serves an analogous purpose.

  On Taos, the reboot kernel call always raises SIGSYS. (However, its functionality would be convenient for the remote operation of servers).

  On Taos, the vhangup kernel call always raises SIGSYS.

  On Taos, the settimeofday kernel call always returns EPERM (the tsh settime command can be used instead; see tsh(n)).