make changes in SYSTARTUP_VMS.COM without starting the system

[Robert Gezelter]

smg_atlas,

While Hoff and Jon have made good comments, I will add one thought.

Make the changes to SYSTARTUP_VMS.COM and then use the editor to write a temporary file (e.g., X.TMP) containing the changed lines. Then execute this file from user SYSTEM with the appropriate privileges enabled (as a general principle, while I am disinclined to turn on all privileges without caution, I would in this case, as to mimic the environment when SYSTARTUP_VMS.COM is running), and run the snipped piece of code.

I have seen far too many instances of errors creeping into SYSTARTUP_VMS.COM. This acts as a guard, detecting many of those errors when the snippet is executed, rather than inconveniently at the next reboot.

- Bob Gezelter, http://www.rlgsc.com

[Jon Pinkley]

Bob has extremely good advice.

In general you will not want to execute the complete vms_startup.com file at any time other than system startup (since it may do many things that are only appropriate at that time).

However, you do want to be sure that what you have added to the startup command file is correct.

So extracting just that part, and saving to a small command procedure is the best way to test that change.

I do that myself, because I have been surprised by typos that don't show up until the next reboot, which can be a long time from when the change was made.

[Hoff]

Would you set up a user that was unfamiliar with bash and with commands including chmod and chown with root access on your production Linux server?

I'd certainly be inclined to avoid that.

For this case, I'd suggest getting access to a test server, and using it to practice and to test changes. To learn. To learn about DCL and syntax, about system management, and the related troubleshooting. Or a week or two of time in one of the available classes on OpenVMS, if that's how you prefer to learn.

Do spend some time in the manuals regardless. No matter how well anyone might know Linux or Unix, that knowledge does not map to OpenVMS commands and system management operations, and assuming similarities can often lead to frustration and even to failure. OpenVMS and Linux are very different beasts.

Within a production environment and operating with full privileges (root access), it is quite feasible to very seriously mess up an Rdb database with the wrong RMU command, or the wrong DCL command. In Linux terms, one errant rm -R / can ruin your whole day. And your whole production environment. OpenVMS has its analogous commands.

And a busted SYSTARTUP_VMS.COM is very low on the "System Breakage" scale.

System privileges on OpenVMS are root on Unix. The level of production damage that can be caused is entirely analogous.

(And we were all once newbies with bash or with DCL, and each of us was once dangerous with root or system privileges. And this whole system management area is the "deep end of the pool", regardless of the platform. Mistakes here can hurt.)

[smg_atlas]

Thanks a lot! guys I really appreciate comments/commands.
ActuallY I am working in an environment where we monitor HP-UX/solaris/Linux systems. And one in a blue moon we have a customer with Openvms environment.
We dont have too much knowledge only except checking devices, memory , error logs.
Thanks very much once again.

regards,