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Startup Procedure
Startup Procedure
BIOS
System Power-up Sequence
BIOS Start-up Sequence
Checking the Drives
Aborted Installation
NVRAM Error
System Reboot or Power Down
This section describes the DAC960PL disk array controller BIOS and start-up procedures.
BIOS
The BIOS provides a single threaded interface to access up to eight system drives on each DAC960PL.
The BIOS presents system drives to the host as large disk drives with 32 sectors per track and 128 heads per cylinder (giving 2 MB per cylinder). Because of the 1024-byte cylinder limit, only the first 2 GB of a large system drive can be accessed through the BIOS. An operating system-specific driver will be required to access data beyond this limit.
System Power-up Sequence
If the SCSI drives are powered up separately from the system, always power up the SCSI drives before the host system. The drives and the host system can be powered up simultaneously, as would be the case when there is a common power switch for both.
BIOS Start-up Sequence
When invoked during power-up, the BIOS will display a sign-on message with its version number and date. The sign-on message looks similar to the following:
DAC960PL BIOS Version x.xx--
Thereafter, the BIOS tries to locate the DAC960PL disk array controller. Once it is located, the BIOS determines if the controller firmware is operational. The BIOS also looks for any initialization message that may be posted by the firmware. If it finds a message, it displays one of the following errors on the screen and aborts the installation process.
DAC960 fatal error--memory test failed
DAC960 fatal error--command interface test failed
DAC960 hardware error--run diagnostics to pinpoint error
DAC960 firmware checksum error--reload firmware
Checking the Drives
If the firmware finds a valid DAC960PL configuration, but it doesn't match the SCSI drives currently installed, one or more of the following messages will be displayed:
Unidentified device found at channel x....
Device identified for chn x, tgt y found at chn x', tgt y'
SCSI device at chn x, tgt y not responding
If any of the above messages are displayed, the firmware will not proceed any further in the initialization process, except to find other mismatches. Then, the BIOS will print out the following message:
DAC960 Configuration Checksum error--run configuration utility
Mismatch between NVRAM and Flash EEPROM configuration
At the next stage, the following message may appear:
Recovery from mirror race in progress
This message will be displayed if the firmware detects that during the last power cycle the system was turned off abruptly, leaving some incomplete write operations.
The following messages may also appear:
Adapter cannot recover from mirror race!
Some system drives are inconsistent!
During the initialization, if the firmware fails to respond to the BIOS inquiry within two minutes, the following message will be displayed:
DAC960 not responding--no drives installed.
The BIOS then asks the firmware for its version number and other information and prints out the following message:
DAC960 firmware version x.xx
One or more of the following messages will be displayed if the firmware reports the associated conditions:
Warning: X system drives are offline
Warning: X system drives are critical
Warning: The following SCSI devices are dead--chn x, tgt y...
No system drives found: None installed
X system drives installed
The BIOS repeats the same process for any additional DAC960PL controllers present in the system. Then it proceeds to boot, if possible, from the first system drive on the first DAC960PL.
Aborted Installation
The Iinstallation aborted message is displayed when the BIOS finds that the configuration of the disk drives, as stored in the NVRAM and flash EEPROM, is different from what the BIOS sees at boot time. When this happens, the cause is often a faulty cable or drive, or a loose connection. Check all of the connectors, cables, drives, and try to boot. If the error persists, it most likely indicates a genuine failure that needs to be corrected. To correct the error, boot MS-DOS and run the configuration utility. See Disk Array Configuration Utility.
NVRAM Error
If the BIOS displays a mismatch between NVRAM and the flash EEPROM configuration, no drives will be installed. Normally this error will not be displayed. If it is, boot MS-DOS and run the configuration utility to recover from the error. See Disk Array Configuration Utility.
System Reboot or Power Down
The DAC960PL disk array controller is a caching controller with 4 MB of cache memory. Data may still be in the cache waiting to be written to the disk drives when the system reports that a write command was completed. It is very important to make sure all data is written to the disk before rebooting or powering down the system; otherwise, data may be lost. It is always a good idea to wait for 15 seconds before resetting or rebooting the system. If using the write-pending LED indicator, wait for 3 seconds after the LED has gone off before resetting or rebooting the system. The optional cache battery-backup module may also be used to prevent data loss.
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