AlphaServer GS160/320 CPU Online Addition and Removal Order Number: EK-GSHPG-RM. A01 This document is for system owners and service providers of AlphaServer 160/320 systems. It describes how to add and replace CPU modules in a running system and restrictions related to that servicing.
July 2001 © 2001 Compaq Computer Corporation. Compaq, the Compaq logo, AlphaServer, and StorageWorks Registered in U.S. Patent and Trademark Office. OpenVMS and Tru64 are trademarks of Compaq Information Technologies Group, L.P. in the United States and other countries. Portions of the software are © copyright Cimetrics Technology. UNIX is a trademark of The Open Group in the United States and other countries. All other product names mentioned herein may be trademarks of their respective companies.
Chapter 1 Overview The AlphaServer GS160/320 systems support the removal and addition of CPU modules while the system is powered on and applications are running. This chapter provides background information so that one can safely service these machines and understand requirements about which CPUs can go where. Chapter 2 outlines the procedures and gives specific operating system examples of replacing a CPU in a running system.
Who may service these systems? Only those with appropriate technical training and experience should attempt to service these systems. What precautions are to be taken? Table 1–2 lists the various power and mechanical hazards in the system. Because these systems use a great deal of power, caution must be exercised when servicing them. Remove all jewelry when working on the systems. The use of ESD straps is required.
What do I need to know about the system clock, CPU variants, and the system box QBBs? Early GS160/320 systems used the B4125 CPU module, which supported a 4-Mbyte backup cache. The QBBs in the early system boxes (BA51A-AA) supported the 4-Mbyte B-cache. With the introduction of the B4166 CPU modules which support an 8-Mbyte B-cache comes a system box (BA51A-BA) with QBBs that support the larger B-cache.
Table 1–4 Comparison of System Boxes System Box Part Number Cache Size Supported by the Box Comments BA51A-AA (54-25043-01/02) 4 Mbytes Though the B4166 CPU has an 8-Mbyte B-cache, only 4 Mbytes are used when placed in this backplane. BA51A-BA (54-25045-01/02) 4 or 8 Mbytes When all CPUs in this backplane are B4166, all use 8 Mbytes of B-cache. If CPUs are mixed, B4125 and B4166 on the same backplane, all are configured for the 4-Mbyte B-cache size.
Note these additional restrictions: • • • • All CPUs in a QBB must be of the same speed, because all QBBs in a GS system operate from one common reference clock. Mixed-speed CPUs within a QBB is an illegal configuration. If a QBB contains a B4125 CPU and it is replaced with a B4166 CPU, the faster B4166 CPU will still be set to run at a slower speed with a 4-Mbyte cache size. At the next power cycle the configuration is reassessed and configured to reflect any new components.
have printouts of the SCM show fru and SRM show config commands. From these displays one can determine the following: • • System clock speed setting 9.0 or 9.6 ns QBB part numbers, which indicate the size of B-cache supported 54-25043-01/02 – 4 Mbytes 54-25045-01/02 – 4 or 8 Mbytes SCM Example SCM_E0> show fru FRUname E Part# [part of display omitted] QBB0 QBB0.PSM QBB0.PWR QBB0.AUX 80 00 00 00 54-25045-01.C01 54-25074-01.L01 54-25017-01.F01 54-25123-01.E01 QBB0.CPU0 QBB0.CPU1 QBB0.CPU2 QBB0.
Open VMS Example >>> show cpu WFSI27, a Compaq AlphaServer GS160 6/940 The CPU is identified as 6/940. From this you can infer that the system clock speed is set at 9.6, since the B4166 CPU is not running at full speed (1001 MHz). What is the limit on the number of cycles a CPU module can be power cycled? CPU modules must not be power cycled (defined as a power-on and a power-off sequence) more than 1,000 cycles. This capability is intended to be exercised as needed, not by test procedures.
Chapter 2 Examples Online addition and replacement of CPUs is used to expand capacity, upgrade components, and replace failed components, while the operating system continues to run. Following are the steps required to replace a CPU. Step 3 is the physical replacement of the CPU; the other steps are performed at the operating system level. 1. Take the CPU offline. 2. Remove power from the CPU.
2.1 CPU Module Handling Review the information on handling the CPU module before beginning the service procedure.
CAUTION: Always wear an antistatic wrist strap when working on the system. See Figure 2–1. Using both hands, one on each module lever, place your index finger on the catch and thumb on the edge of the lever just below/above the arrow. First squeeze to release the lever and then pull both levers away from the module to release it from the QBB backplane. Remove the module. Insert the replacement module and then press the levers down.
2.2 Tru64 UNIX Procedure For more information, refer to the Tru64 UNIX manual Managing Online Addition and Removal.
See Table 1-1 for the minimum versions of the operating system, firmware, and WEBES needed to support online service. Also be sure to understand the distinctions and restrictions in Chapter 1 relating to the CPU models and the system boxes. Refer to Section 2.1 for instructions on removing CPU modules from the system box. Example 2-1 shows the Tru64 UNIX commands that can be used in the online removal and replacement of a CPU module. Take the CPU offline.
2.3 OpenVMS Procedure For more information, refer to OpenVMS Version 7.3 New Features Manual. Example 2–2 Replacing a CPU Module $ SET CPU/POWER=OFF 3 $ SHO CPU WFSI27, a Compaq AlphaServer GS160 6/1001 $ STOP/CPU 3 %SYSTEM-I-CPUSTOPPING, trying to stop CPU 3 after it reaches quiescent state %SYSTEM-I-CPUSELECTED, a selected CPU is attempting the requested transition Multiprocessing is ENABLED. Streamlined synchronization image loaded.
$ SHOW CPU WFSI27, a Compaq AlphaServer GS160 6/1001 Multiprocessing is ENABLED. Streamlined synchronization image loaded. Primary CPU = 000 CPU sets: Active Configure Powered Down Potential Autostart Failover $ 0-7 0-7 None 0-15 0-31 None See Table 1-1 for the minimum versions of the operating system, firmware, and WEBES needed to support online service. Also be sure to understand the distinctions and restrictions in Chapter 1 relating to the CPU models and the system boxes. Refer to Section 2.
