Yesterday I carelessly powered off my Sun blade 2500 when I
was using Cadence Composer in a NIS server. When I
reboot the sun pc,I found that the sun pc hang up after set default gateway.I wonder what is the reason?

Because the trouble above I just can reinstall solaris9.0 to repair
the problem. After installing solaris9.0, I longin to NIS server and
open Cadence Composer. But I can not open the circuit schematic
figure for editing just reading. Another Circuit schematic figure is ok!
From error message I found that the file associated the circuit schematic
has been locked, So i just can read it but not edit. I removed some lock
files, but after restore cadence, the lock file also be produced.
How to solve the problem? Can you help me ?

maybe you're not removing the correct lock file?

why not just open the file and save it under another name. The new file shouldn't have the same lock file issue. Otherwise perhaps the read-only setting is a config issue in your application.

You have a system with Solaris on the Sun Blade 2500 and Windows on a SunPCi internal board, correct ?
Which version of of Windows ?
Solaris' host main role is to act as a NIS server.
You reinstalled Solaris 9 because Windows hanged aftert setting the default gateway ?
That fixed the hanging problem ?? This is puzzling, do you really mean you wiped out the system and intalled a fresh one, or just you fixed the NIS configuration ?

You have also an application problem, Cadence no more want to update some of its files, while others have no problem .

Where is running Cadence, Solaris or Windows ?
On what file system are the problem files located ?
Are there error messages logged or displayed somewhere ?

I want to troubleshoot this problem because I have many import files in this locked directory.
I must open it for editing.

The candence is running in the NIS Server maintained by University.
The locked filesystem is located in my HOME directory because I started icfb & for COMPOSER
in my HOME directory and made a new library named by Newdriver. Due to this trouble I just
can open the Newdirver for reading not editing. I spent much time to draw it, I don*t want to
lose it.
I login to the University NIS server by a SUN Blade 2500 in my lab.
And the Sun Sparc platform is Solaris9.0 with a static IP assigned by University network
administrator.
I mean I carelessly power off my sun blade 250 when I was using Cadence in university
NIS server, After rebooting and set the default gateway for my sun pc, the Sun blade 2500
seems to hang up. I have never meet this problem so that I just can restall solaris9.0 in
my sun blade 2500. After restoring the sun blade 2500, I enter the university NIS server
and start cadence to open my working library directory. But I just can open this directory
for reading not editing because the error message shows me that some files are locked by
user s042530(this is my ID for logining to university NIS server ). Really, I can creat another
one to edit, but I am insterested in how to solve this problem? Please tell me? Or I must
ask my network administrator for troublshooting this problem! Thank you!

Your answer makes me feeling that you are confusing NIS and NFS.
Anyway I guess this is really too tighted with the application and your administrator should be of better help than we can.