48
Maintenance Action Plans
Check that all SCSI devices other than the end devices have internal termination disabled.
A DE terminator on a SE bus or an SE terminator on a DE bus will cause the bus to be unusable.
3
If there are SCSI termination problems, power down the Scalar 24 and correct them.
If you corrected SCSI termination problems, go to
SCSI Health Check
.
If SCSI termination is OK, go to
Check for Multiple SCSI IDs
on page 48.
4
If you powered down the Scalar 24, turn it back on.
Check for Multiple SCSI IDs
If two or more devices on the same SCSI channel are configured at the same SCSI ID, only one of those
devices will be seen by the SNC. Data transfers to that device will be unreliable.
1
Enter the
scsiShow
command from the service terminal.
For more information, see the
scsiShow
on page 106.
2
Write down the SCSI IDs of all devices connected to each SCSI channel.
3
Check that only one device is set to each ID for each SCSI channel.
Assign a new SCSI ID to any conflicting target device.
4
Check that for each SCSI Channel, no devices are set to ID 7 except the SNC channel ID.
If a target device is set to the same ID as the SNC (ID 7), the bus will be unstable and data corruption
may result.
5
If you do not need to correct any SCSI IDs, go to
Improper Device Type
.
6
If you corrected any SCSI IDs, reboot the Scalar 24.
7
After it finishes booting, enter the
scsiShow
command.
8
Compare the list of attached devices with the physical devices.
9
If not all of the physical devices are shown, go to
Improper Device Type
on page 48.
10
If all of the physical devices are shown, go to
SCSI Health Check
on page 50.
Improper Device Type
1
Check to be sure that all the devices attached to a single SCSI bus are of the same type.
Only low voltage differential devices may be attached to low voltage differential SCSI channels.
When a mix of Ultra2/3 SCSI and Ultra SCSI devices are connected to a single bus, the bus will run at
the Ultra SCSI speed. Because the bus will auto-adjust to the slowest speed, it is not recommended
that you run both Ultra2/3 SCSI and Ultra SCSI devices on the same bus.
2
Replace any improper SCSI device with a proper device.
3
Reconnect the SCSI cable.
CAUTION
If in this procedure you determine that you need to correct any SCSI
IDs, all I/O to the SNC must be stopped and the SNC must be turned
off.
CAUTION
If in this procedure you determine that you need to replace a SCSI
device, all I/O to the SNC must be stopped and it must be turned off.
Summary of Contents for SNC 4000
Page 1: ...www adic com ADICSNC 4000User sGuide ADVANCED DIGITAL INFORMATION CORPORATION...
Page 10: ...4 SNC 4000 Introduction...
Page 40: ...34 Removal and Replacement Procedures...
Page 140: ...134 Service Port Command Reference...
Page 147: ...SNC 4000 User s Guide 141 fcConnPortModeGet...
Page 148: ...142 Diagnostic Command Reference...