uadmin(2)

NAME

     uadmin - administrative control

SYNOPSIS

     #include <sys/uadmin.h>

     int uadmin(int cmd, int fcn, uintptr_t mdep);

DESCRIPTION

     The uadmin() function provides control for basic administra-
     tive functions. This function is tightly coupled to the sys-
     tem administrative procedures and is not intended  for  gen-
     eral  use.  The  argument  mdep  is  provided  for  machine-
     dependent use and is not defined here.

     As specified by cmd, the following commands are available:

     A_SHUTDOWN
           The system  is  shut  down.  All  user  processes  are
           killed, the buffer cache is flushed, and the root file
           system is unmounted. The action to be taken after  the
           system  has  been  shut  down is specified by fcn. The
           functions are generic; the hardware capabilities  vary
           on  specific machines.

           AD_HALT
                 Halt the processor(s).

           AD_POWEROFF
                 Halt the processor(s) and turn off the power.

           AD_BOOT
                 Reboot the system, using the kernel file.

           AD_IBOOT
                 Interactive reboot; user is prompted  for  boot-
                 able program name.

     A_REBOOT
           The system stops immediately without any further  pro-
           cessing.  The  action to be taken next is specified by
           fcn as above.

     A_DUMP
           The system is forced to panic immediately without  any
           further  processing and a crash dump is written to the
           dump device (see dumpadm(1M)).  The action to be taken
           next is specified by fcn as above.

     A_REMOUNT
           The root file system is  mounted  again  after  having
           been  fixed.  This  should  be  used  only  during the
           startup process.

     A_FREEZE
           Suspend  the  whole  system.   The  system  state   is
           preserved  in the state file. The following three sub-
           commands are available.

           AD_COMPRESS
                 Save the system state to  the  state  file  with
                 compression of data.

           AD_CHECK
                 Check  if  your  system  supports  suspend   and
                 resume.     Without    performing    a    system
                 suspend/resume,  this  command  checks  if  this
                 feature is currently available on your system.

           AD_FORCE
                 Force AD_COMPRESS  even  when  threads  of  user
                 applications are not suspendable.

RETURN VALUES

     Upon successful completion, the value  returned  depends  on
     cmd as follows:

     A_SHUTDOWN
           Never returns.

     A_REBOOT
           Never returns.

     A_FREEZE
           0 upon resume.

     A_REMOUNT
           0.

     Otherwise, -1 is returned and errno is set to  indicate  the
     error.

ERRORS

     The uadmin() function will fail if:

     EPERM The effective user  of  the  calling  process  is  not
           super-user.

     ENOMEM
           Suspend/resume ran out of physical memory.

     ENOSPC
           Suspend/resume could not allocate enough space on  the
           root file system to store system information.

     ENOTSUP
           Suspend/resume not supported on this platform.

     ENXIO Unable to successfully suspend system.

     EBUSY Suspend already in progress.

USAGE

     When a UFS file system is mounted with logging enabled, file
     system  transactions  that  free blocks from files might not
     actually add those freed blocks to the  file  system's  free
     list  until  some  unspecified  time  in  the  future.  This
     behavior improves file system performance but does not  con-
     form  to the POSIX, Single UNIX Specification, SPARC Confor-
     mance Definition, System  V  Application  Binary  Interface,
     System  V Interface Definition, and X/Open Portability Guide
     Standards, which  require  that  freed  space  be  available
     immediately.  To enable standards conformance regarding file
     deletions or to address the problem of  not  being  able  to
     grow  files  on a relatively full UFS file system even after
     files  have  been  deleted,   disable   UFS   logging   (see
     mount_ufs(1M).

SEE ALSO

     dumpadm(1M), kernel(1M), mount_ufs(1M), uadmin(1M)