Paul, It sounds like you are running the Crossroads router in "Fibre Channel to SCSI Mapping Mode" of auto. Change the mode to "Indexed" and this should fix your problem. The mapping mode determines how the targets behind the router (i.e. tape that are attached to the SCSI side of the router) are seen by Fibre Channel hosts on the network. Specifically, the various addressing modes determine how Fibre Channel LUNs are mapped to the SCSI peripherals on the router, and how that mapping can change when you reboot or reconfigure the router. You normally want to use indexed mode to ensure that particular target/luns on the SCSI side of the router are persistently presented as the same LUNs on the Fibre Channel side of the router, regardless of whether devices have been removed on the SCSI side or were turned off when the router booted. Mike
-----Original Message----- From: Paul Caron [mailto:caron@sig.com] Sent: Friday, November 01, 2002 11:02 AM To: toasters@mathworks.com Subject: Crossroads Problems
We are currently trying to implement a SAN backup solution involving several F840 (ONTAP 6.2R2, latest FW) and R100 (ONTAP 6.2.1, latest FW) filers, a Brocade Silkwork 3800 switch (kernel 5.3.1, fabric OS 3.0), a Crossroads 10000, an ATL P7000 tape drive library with 8 SDLT drives, and Commvault Galaxy software (4.1.0, Build 26). We have tried firmware versions 4.03.16, 4.03.17, and 4.19 on the Crossroads 10000.
The problem we are experiencing is that the devices on our filers which represent the SAN attached tape drives (shown by sysconfig -t) get randomly recreated every time the Crossroads reboots. Since we can't guarantee which devices will get assigned to which tape drive LUN, they often do not match those configured in the Commvault Galaxy backup software. The resulting mismatch causes many backup problems. It appears as though the Crossroads is not presenting the tape drives available on the ATL P7000 in the same order every time it reboots.
We have read through the information available at http://www.netapp.com/osn/info/config.html#fcsan. This site shows support for the Brocade 3800. Although they do not call out support for the Crossroads 10000 specifically, they do show a wide range of options using various SCSI-FIBER bridges with a variety of libraries. The StorageTek library they show uses a Crossroads 42xx series switch.
Has anyone else run into this situation? Is there any way of compensating for this on the Netapp filers? I realize that it would be better if the Crossroads would present the tape drive LUNs in the same order every time, but that doesn't appear to be configurable. It would help if we could permanently assign the devices to the tape drive LUNs on the filers.
BTW, we have received suggestions regarding using the Netapp "storage alias" and "storage unalias" commands. However, since the Galaxy backup software relies on the actual device names (i.e. rst0l, nrst0l, urst0l, etc.) this hasn't helped us so far.