Devices are not properly detected for an EMC Symmetrix array using ANSI SCSI revision 02
Issue
When configuring new logical units (LUs) on an EMC Symmetrix storage array newly-discovered LUs are reported as having an "ANSI SCSI revision" of 02 in /proc/scsi/scsi:
Host: scsi0 Channel: 00 Id: 00 Lun: 1
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 02
This is also reported in the kernel log (dmesg) when registering the devices:
scsi 0:0:1:0: Direct-Access EMC SYMMETRIX 5773 PQ: 0 ANSI: 2
scsi 0:0:2:0: Direct-Access EMC SYMMETRIX 5773 PQ: 0 ANSI: 2
In some instances there may be logical unit numbers (LUNs) much higher than the expected values for the array (greater than 40,000 in some cases), for example:
Host: scsi0 Channel: 00 Id: 00 Lun: 47123
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 00 Lun: 47106
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 02
In either case the LUs are not properly registered with the system and are unavailable for normal IO and the process of scanning for new LUs on the array may appear to "hang" (block for extended periods without making apparent progress).
Environment
Red Hat Enterprise Linux hosts attached to EMC Symmetrix iSCSI or fibre channel attached storage running:
- Red Hat Enterprise Linux 4
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
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