Dear All,

We have a CentOS6.3 system with qlogic ISP2532 8gb fc card.
We are constantly getting error messages of following type in /var/log/messages

Apr 14 17:51:42 mds1 kernel: sd 9:0:0:6: [sdh] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
Apr 14 17:51:42 mds1 kernel: sd 9:0:0:6: [sdh] Sense Key : Illegal Request [current]
Apr 14 17:51:42 mds1 kernel: sd 9:0:0:6: [sdh] Add. Sense: Invalid field in cdb
Apr 14 17:51:42 mds1 kernel: sd 9:0:0:6: [sdh] CDB: Write(16): 8a 00 00 00 00 03 43 e4 f8 00 00 00 48 00 00 00

Though disk read and write are happening, but we think it is slow. I wanted to know what do these messages indicate ? Are they harmful ? And if anything can be done to it.

Thanks and Regards
Dilip G Sathaye

You don't say whether you're using the QLogic drivers from their website, or the native Linux drivers (those could be a source of the messages). You also don't say what kind of SAN you're hooked up to, or if you're using multipathing or not, but it either points to a driver issue or a zoning issue. The best people to ask would be the SAN vendor, and you may also want to check with QLogic as to what they suggest for your system.

It is even possible there is a software compatibility problem...

Or that a fiber cable may be bad - especially if you have dual path available (and the throughput would be about half what it should be).

Giving few details which I missed mentioning earlier.

We are using a DX-80 Fujitsu storage ,it has total 8 FC ports of 8gb . Those are directly connected to 4 Fujitsu servers using optical cable ( LC-LC ). No SAN switch. We have not used any specific driver from Qlogic site. We used Fujitsu's Eternus multipath driver on top of this. This setup is used to provide lustr filesystem.

Thanks and Regards
Dilip G Sathaye

Ok...which brings us back to what was said previously:

• Bad cable? Did you check them?
• Software incompatibility? Did you check the requirements?
• Bad/incorrect driver? Did you look for/download/try the one from QLogic?
• SAN issue? Did you contact the SAN team or ask your SAN vendor?

Posting follow-up information is fine, but without acknowledging/trying ANYTHING that was suggested previously, there's little else we can tell you.