Technical Bulletin #16

For All Users of ClearCase for UNIX on SGI Platforms

August 16, 1996

ClearCase not supported on SGI's IP28 processor without patch

Rational has been informed that running ClearCase on SGI's IP28 processor may be affected by corruption of kernel memory.

SGI states in its release notes for IRIX 6.2 on the Indigo2 IMPACT 10000 that any kernel modules must be compiled with a special option to eliminate the potential for data corruption within the kernel on machines that contain this processor. The ClearCase MVFS is such a module. Machines with the IP28 processor were released subsequent to ClearCase Release 2.1.

The IP28 processor is included in SGI's Indigo2 IMPACT 10000 model. To determine whether a system has an IP28 processor, run uname -m. This returns the processor type, IP28, IP25, IP22 and so forth.

Warning: Although ClearCase installs on these machines, and appears to work, corruption of kernel memory is likely. Rational has no information that this problem affects data in the MVFS.

For reference, here is the SGI release note:

1.4 Compiler Options

It is crucial that all kernel modules used on the Indigo2 10000 be built with the -TARG:t5_no_spec_stores compiler option. Not using this option will cause data corruption within the kernel. Using this option is not compatible with the Power Indigo2, so separate driver binaries must be provided if both workstations are to support the same device. See /var/sysgen/Makefile.kernio for a detailed listing of the required compiler options.

Patch 2.1-227 corrects the problem. With this patch, ClearCase is supported on these processors. Without this patch, do not install ClearCase on systems with the IP28 processor. If you have already installed on a system with the IP28 processor, deinstall ClearCase immediately and obtain the patch before reinstalling it.

What to do

Obtain patch 2.1-227 from Rational Customer Support.

If you have an anonymous FTP capability: Use the ftp program to connect to host ftp.rational.com. Follow the instructions for obtaining ClearCase patches.

Those without FTP or WWW access may call Rational Customer Support (see phone numbers below). Request that one or more patches be sent to you by electronic mail or magnetic tape.

Install the appropriate patch in the release area for ClearCase 2.1. Follow the instructions included in the patch's .doc file.

Any Questions?

If you have any questions regarding the situations discussed in this Technical Bulletin, please contact Customer Support at support@rational.com or (781) 676-2450 in Massachusetts or 31-23-569-4310 in the Netherlands.