IRIS 3010, Руководство пользователя, Страница: 70 / 145

4-28 IRIS OWNER’S GUIDE
SERIES 3000 Version 1.0
Workstation Administration
4.5.2 Recovery with init
When U
nix
software is booted, it starts the initialization program, init , which
controls the startup sequence.
The
init program provided with an IRIS workstation has been modified so that
it attempts to recover from the most common file system errors. For most
errors, init recovers automatically but does not repair the cause of the problem.
Therefore, once the system comes up, you should repair the source of the
problem.
Repairing the problem usually entails editing the damaged files or reloading
the files from a backup tape.
When it starts running, the
init program invokes a single-user shell by calling
the switch user program, su . Upon startup, su looks in the file /etc/passwd for an
account called root . The su program then starts a shell of the type specified in
the file /etc/passwd for the account root . (The default shell is the C shell,
/bin/csh .)
During this process, the system does not boot correctly if it encounters any of
these conditions:
1. The /etc/passwd file is missing.
2. The entry for root is missing or in error in the /etc/passwd file.
3. Any other files critical to starting U
nix
are missing or corrupted.
If any of these problems exists, init may be unable to execute the su program,
or su may execute too quickly. The first time an error occurs, su should take no
more than 15 seconds to execute; on subsequent errors, su should take no more
than 30 seconds to execute.
If
init cannot execute su , it displays this message:
execlp of /bin/sh failed; errno =
n
Refer to the error numbers listed in the introduction to Section 2 in the U
nix
Programmer’s Manual for the meaning of n .
If su executes too quickly, it displays a message explaining the problem. For
example:
SINGLE USER MODE
SU is broken