3PAR InForm Operating System 2.3.1 MU1 Release Notes (320-200213 Rev B, May 2010)

2.9
InForm OS Version 2.3.1 MU1 3PAR InForm Operating System Release Notes
2.6 Limitations of the InForm OS
2.6.1 Fibre Channel/SCSI Interface
The InForm OS does not provide user-level control on write caching via the SCSI mode select
command. Write-caching is on by default. Deferred errors will never be reported after status is
sent for a write command. The InServ Storage Server system software may go into write-
through mode while handling certain events such as a loss of battery charge or a faulty node
(although a faulty node will not cause an InServ with 4 or more nodes to go into write-through
mode).
The following SCSI commands are supported but are effectively null operations:
rezero_unit, format_unit, seek, verify, sync_cache, send_diag. The SCSI command
write verify performs a write operation but not a verify operation.
Head-of-queue and ordered-queue are not supported. Simple-queue currently defaults to
unrestricted reordering.
2.6.2 Connectivity Issues with Remote Copy IP Interfaces for 100Mbps Switch
Ports
3PAR has observed connectivity issues with Remote Copy IP interfaces connected to 100Mbps
switch ports that can cause the Remote Copy links to negotiate their speed and duplex settings
incorrectly. This issue has the potential to cause the Remote Copy IP links, as well as the
connected switch ports, to stop working (e.g., states of offline, down, unknown, loss_sync). In
many cases, the 3PAR controller-node has to be rebooted to clear this condition.
In some configurations, depending on switch type and InForm OS version, selecting Auto-
negotiation has overcome the problem, while in others, forcing the ports to 100/Full has
provided relief. In all cases, utilizing a 1Gbps switch port has alleviated all negotiation issues.
To resolve this issue, 3PAR requires all Remote Copy IP ports to be connected to a 1Gbps switch
port in order to alleviate the observed connectivity and negotiation related problems.
This reduction in functionality is described in Product_Alert_247 200011-
RevA_RCIP_Link_Speed.