[padb-users] start using padb on TORQUE

[David Singleton]

On 11/26/2010 07:53 AM, Ashley Pittman wrote:

>> * We run all jobs under project groups which are not user login groups.
>>   That causes grief for "rsh node gdb ..." type debugging because of
>>   insufficient privileges.  Since this is a common problem for us, we
>>   have a variant of newgrp that we can insert in remote commands to
>>   overcome this, eg
>>       rsh node nfnewgrp projgroup gdb ...
>>
>>   Note that all variants of PBS support users nominating their jobs
>>   execution group (the group_list/egroup job attributes) but I dont know
>>   how commonly this is exercised.
>
> In this context I'm assuming by group you mean a pbs concept and not a linux group (from /etc/groups), if it was the latter and usernames were the same this would be a non-issue.
>

I do mean Linux groups. ptrace appears to require matching gids.

With matching gid:

vayu2:~ > id
uid=478(dbs900) gid=1090(z00) 
groups=900(ANUSF),998(quotasu),999(rashadm),1000(sysadmin),1090(z00),1094(z10),1438(s55),3040(z07),3136(c23),3191(c25),4004(abaqus),4167(vasp4),4285(z15),5050(libgoto),5146(z28),5501(gpu)
vayu2:~ > gdb /bin/tcsh 16677
GNU gdb (GDB) Red Hat Enterprise Linux (7.0.1-23.el5_5.2)
...
Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
0x00007ffff7716240 in __read_nocancel () from /lib64/libc.so.6
(gdb)


Change group:

vayu2:~ > newgrp c23
vayu2:~ > id
uid=478(dbs900) gid=3136(c23) 
groups=900(ANUSF),998(quotasu),999(rashadm),1000(sysadmin),1090(z00),1094(z10),1438(s55),3040(z07),3136(c23),3191(c25),4004(abaqus),4167(vasp4),4285(z15),5050(libgoto),5146(z28),5501(gpu)
vayu2:~ > gdb /bin/tcsh 16677
GNU gdb (GDB) Red Hat Enterprise Linux (7.0.1-23.el5_5.2)
...
Reading symbols from /bin/tcsh...(no debugging symbols found)...done.
Attaching to program: /bin/tcsh, process 16677
ptrace: Operation not permitted.
/home/900/dbs900/16677: No such file or directory.
(gdb)


Cheers,
David