FCO 5900-0001, RZ57s in DS5900 systems experiencing SCSI bus hangs

This Field Change Order (FCO) addresses a critical issue in DS5900 servers where RZ57 disk drives can cause SCSI bus hangs, particularly in configurations with four or more drives on the same SCSI bus. The recommended solution is to replace the existing RZ57 disk drives with RZ58 disk drives.

The FCO outlines the applicability to DS5900 systems, provides a quick check (uerf -r 300 | more) to identify the presence of RZ57 drives, and details the replacement procedure. Key steps include system shutdown, ensuring customer data backup before commencing work, proper antistatic procedures, carefully removing RZ57 drives (referencing the DECsystem 5900 Maintenance Manual), configuring new RZ58 drives with identical SCSI addresses, installing the RZ58s, and verifying the new drives through power-up diagnostics and an optional, destructive console device test. The FCO also specifies reporting the activity on the LARS form and provides charging information based on contract type and service location. The estimated time for this replacement is 1.0 MFIT HRS.