topic RMS-RTB- (record too large) message from DCL with SYS$INPUT a mailbox in Operating System - OpenVMS

RMS-RTB- (record too large) message from DCL with SYS$INPUT a mailbox

GuentherF — Wed, 01 May 2013 21:08:35 GMT

I have an application which spawns a detached process running LOGINOUT.EXE. The creator process uses two mailboxes for SYS$INPUT and SYS$OUTPUT to communicate with DCL in the created process. At one site a command line with 300-something characters sent through the mailbox to SYS$INPUT of the created process generates the RMS-RTB- message (record too large).

However, the very same command line works interactively and on my local system it doesn't fail even with command lines longer than 500 bytes.

Before looking into DCL sources, does anyone have an idea which quota/limit DCL uses to size the command line input buffer?

Thanks,

Guenther

Re: RMS-RTB- (record too large) message from DCL with SYS$INPUT a mailbox

abrsvc — Thu, 02 May 2013 11:01:11 GMT

This is one case where the version of VMS is critical. IIRC there were changes in this area.

What version is involved here?

Dan

Re: RMS-RTB- (record too large) message from DCL with SYS$INPUT a mailbox

John Gillings — Mon, 06 May 2013 05:09:33 GMT

Guenther,

Mailboxes have a maximum message size. What it is depends on how it is created (and, to some extent, what version of OpenVMS you're using). See SHOW DEVICE/FULL MBAnnn.

See SYSGEN DEFMBXMXMSG for the default size. If you're creating it yourself from DCL, see CREATE/MAILBOX/MESSAGE_SIZE, or the maxmsg parameter for $CREMBX

Re: RMS-RTB- (record too large) message from DCL with SYS$INPUT a mailbox

GuentherF — Wed, 08 May 2013 01:06:07 GMT

Yes indeed, the version is critical. The DCL command buffer size for non-terminal input was changed in V7.3-something to 1024 (I think) from 256 before.

And surprisingly (or not) the customer was running V7.2 and we tested on V7.3 in our lab.

Thanks,

Guenther