Technical Bulletin #15

For All Users of ClearCase for Unix, Releases 2.0.2, 2.0.3, and 2.1

April 26, 1996

Mandatory patch for SunOS, Solaris, HP-UX, Digital Unix, OSF/1 and some UnixWare systems

Rational Engineering has created a mandatory patch as a workaround to a database recovery problem related to a flaw in BSD-based UNIX systems.

The BSD fast file system can fail to safely reallocate block fragments on disk. If a crash, power failure, or improper shutdown occurs while there are unsafe fragment reallocations, ClearCase databases may be corrupted when the system is brought back up.
The conditions that allow this to happen occur in an extremely small window. We believe this happens rarely.
This problem affects any UNIX application that uses small record sizes and has been present in BSD-based systems for many years.

As soon as Rational found the problem, we prepared this mandatory patch to protect our customers. Rational has reported this problem to all the affected operating system vendors.

The problem is known to affect SunOS, Solaris, HP-UX, Digital UNIX, OSF/1, and UnixWare systems with the UFS file system. The full list is in the tables below.

The symptoms of the problem are low-level Vista or Raima database errors recorded in the db_server_log or vobrpc_server_log. If you encounter such errors, please call Rational Customer Support.

Whether you have seen such errors or not, the patch is mandatory. The patch may result in a small increase in database size, from 0 to 32k per VOB or view.

ClearCase 2.1

Architecture	Patch Number
SunOS 4.1.x Solaris 2.x	2.1-122 2.1-123
OSF/1 Alpha 2.x, 3.x, Digital UNIX 3.x	2.1-124
HP-UX 9.0.x	2.1-125
HP800 HP-UX 9.0.x	2.1-126
HP-UX 10.x	2.1-127
UnixWare 2.0.x	2.1-128

ClearCase 2.0.2 and 2.0.3

Architecture	Patch Number
SunOS 4.x Solaris 2.x	2.0.3-127 replaced by 2.0.3-135 2.0.3-128 replaced by 2.0.3-134
OSF/1 Alpha 2.x, 3.x, Digital UNIX 3.x	2.0.3-129
HP-UX 9.0.x	2.0.3-130
HP800 HP-UX 9.0.x	2.0.3-131
HP-UX 10.x	2.0.3-132
UnixWare 2.0.x	2.0.3-133

What to do

Determine the patch number from the table.

Obtain the patch 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.

If you have WorldWide Web access: Connect to <http://www.rational.com/> and obtain the patch from the Customers Only Technical Information Tree.

If you do not have FTP or WWW: Call Rational Customer Support (see phone number 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 2.0.2, 2.0.3, or 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.