Sun System Handbook - ISO 3.4 June 2011 Internal/Partner Edition | |||
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Solution Type FAB (standard) Sure Solution 1001155.1 : Dual Ultra320 SCSI Host Adaptors installed in Sun Fire V440 Servers may not see devices on the SCSI Bus.
PreviouslyPublishedAs 201548 Product Sun Fire V440 Server Bug Id <SUNBUG: 6386284> Part
Impact Dual Ultra320 SCSI Host Adaptors installed in Sun Fire V440 Servers may in some cases not recognize devices on the SCSI Bus. This can occur due to electrical noise on the SCSI Bus generated by the V440 power supply. Contributing Factors This has been observed in only a few instances, but could potentially occur with any device attached to the Dual Ultra320 SCSI HBA in a Sun Fire V440 when the HBA is run in Low Voltage Differential (LVD) mode. It can occur with either the RoHS (375-3365-01) or non-RoHS (375-3191-01) versions of the card. Symptoms When this issue is present, "probe-scsi" at the OBP prompt will not find attached SCSI devices. Root Cause The noise observed is a 90KHz periodic waveform which is part of the AC source input (power factor correction) of the power supply. This section of the power supply has not changed since FCS so all revisions of the power supply should show this issue. Checking the 5 Volt on the motherboard, it is observed that the V440 has a 250mV peak-peak noise on it. It was also observed that at the SCSI connector this same noise is larger (1.0V peak-peak). Running the HBA in Single-Ended mode reduced this noise to 580mVp-p. Workaround For customers who experience this issue on a Sun Fire V440 Server, it is recommended to configure the SCSI Bus for Single-Ended (SE) mode. This can be done by installing a SE SCSI terminator. The Sun part number for this terminator is 150-2267-01. Note: Running the SCSI Bus in SE mode limits the bus speed to 40MB/sec and decreases the maximum SCSI Bus length. Resolution
Modification History Date: 15-MAY-2007
Previously Published As 102547 Internal Comments Related Information
Internal Contributor/submitter [email protected] Internal Eng Business Unit Group KE Authors Internal Eng Responsible Engineer [email protected] Internal Services Knowledge Engineer [email protected] Internal Escalation ID 1-16623170 Internal Kasp FAB Legacy ID 102547 Internal Sun Alert & FAB Admin Info Critical Category: Significant Change Date: 2006-08-04 Avoidance: Hardware Responsible Manager: null Original Admin Info: null Product_uuid d9146f34-fb56-4421-8498-f9ecb90a1349|Sun Fire V440 Server Attachments This solution has no attachment |
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