Article 167041 of comp.os.vms: DIGITAL Cover Letter for the OpenVMS[TM] Alpha Version 7.1 SCSI Device Naming Advisory AV-R541A-TE February 1997 Dear OpenVMS Customer, DIGITAL requires a configuration correction for all OpenVMS Alpha Version 7.1 systems that are using the new SCSI device naming feature available in OpenVMS Alpha Version 7.1. This feature introduced SCSI port allocation classes to facilitate the use of shared SCSI buses in an OpenVMS Cluster system. When the new SCSI device naming feature is enabled, the SCSI port with the OpenVMS device name PKA must have a defined port allocation class of 0, or a positive integer. This is required in all cases, regardless of whether PKA is connected to a shared (multihost) bus or a private bus. Failure to set a port allocation class for PKA, or setting it to -1, can cause some I/O operations to be issued to the wrong SCSI device, causing data corruption or loss. This requirement is not currently enforced by OpenVMS Alpha Version 7.1 software. Therefore, you must make sure that your systems adhere to it. You can use the following procedure to check for compliance with this requirement. You should perform this check on each OpenVMS Alpha Version 7.1 system in your OpenVMS Cluster system. 1. Enter the following command to determine if the new SCSI device naming feature is enabled: $ WRITE SYS$OUTPUT F$GETSYI("DEVICE_NAMING") If the value displayed is 0, the new SCSI device naming feature is not enabled on this node, and the node does not require any further checking. If the value displayed is 1, the new SCSI device naming feature is enabled on this node, and you must proceed to step 2. 2. Check the SCSI port allocation class definitions in the SYS$SYSTEM:SYS$DEVICES.DAT file. The SYS$DEVICES.DAT file is an ASCII text file that can be typed, searched, or examined with a text editor. Note that this file usually resides in SYS$COMMON:[SYSEXE] and can be shared by multiple nodes in an OpenVMS Cluster system. Therefore, entries in this file are usually in the following node-specific format: [Port $PKA] Allocation Class = Also, if there are multiple entries for a specific $PKA port, only the last one applies. The following command can be used to scan for the port al- location class specified for the PKA bus and will find all instances, including duplicates: $ SEARCH SYS$SYSTEM:SYS$DEVICES.DAT/MATCH=AND/WINDOW=(0,2) PORT,PKA You can use the output of this command to verify that a port allocation class of 0 or a positive integer value has been specified for the PKA device for each node that uses this SYS$DEVICES.DAT file. SCSI port allocation classes can be set or changed using the SYS$MANAGER:CLUSTER_CONFIG.COM command procedure. For informa- tion about setting port allocation classes, see Section 6.2.15 in the OpenVMS Cluster Systems manual. For more information about using or changing SCSI port alloca- tion classes, see Section 3.11.8 in the OpenVMS Version 7.1 New Features Manual and Section 6.2 in the OpenVMS Cluster Systems manual. DIGITAL would also like to clarify and emphasize the require- ments for using the new SCSI device naming feature in a mixed- version OpenVMS Cluster system. The new SCSI device naming feature must not be used in a mixed- version OpenVMS Cluster system unless all nodes in the cluster are running either of the following: o OpenVMS Version 7.1 o OpenVMS Version 6.2-xxx with the OpenVMS Cluster Compatibil- ity Kit for Version 6.2 installed. For example, this means that the new SCSI device naming feature must not be used in a mixed-version OpenVMS Cluster system that includes a system running OpenVMS Version 7.0. Failure to follow this configuration requirement can cause some I/O operations to be issued to the wrong served SCSI device, causing data corruption or loss. For more information about the OpenVMS Cluster Compatibility Kit for Version 6.2, see Section 4.15.1.2 in the OpenVMS Version 7.1 Release Notes. DIGITAL appreciates your cooperation and patience. We regret any inconvenience that this correction causes. ©Digital Equipment Corporation. 1997. All rights reserved. ___________________ [TM] The following are trademarks of Digital Equipment Corporation: DIGITAL, OpenVMS, VAX, VMS, and the DIGITAL logo. -------------------------- pure personal opinion --------------------------- Stephen 'Hoff' Hoffman OpenVMS Engineering hoffman@xdelta.enet.dec.com OpenVMS Frequently Asked Questions (FAQ): http://www.openvms.digital.com