I think I got it what is happening.. Please see my comments below.. > -----Original Message----- > From: Gianluca Cecchi [mailto:gianluca.cecchi@xxxxxxxxx] > Sent: Tuesday, November 29, 2011 12:29 AM > To: device-mapper development > Subject: Re: info on enabling only one path with rdac and > DS4700 > > On Mon, Nov 28, 2011 at 9:13 PM, Gianluca Cecchi wrote: > > On Mon, Nov 28, 2011 at 7:05 PM, Moger, Babu wrote: > [snip] > >> RHEL 5.7 has the patch already as I know. You can check to be sure. > Can you also add "scsi_mod.scsi_logging_level=5056" in kernel line to > get more information on what else is going on. > > > > Ok, I have verified that the patch should be applied. > [snip] > > So I'm going to add the scsi logging parameter you suggested and see. > > > > Unfortunately it seems that rh el 5.x kernel doesn't support that > scsi_mod kernel module option directly at kernel line > # cat /proc/cmdline > ro root=/dev/VolGroup00/LV_root rhgb quiet > scsi_mod.scsi_logging_level=5056 > > In messages: > Nov 29 07:00:03 testserver kernel: Unknown boot option > `scsi_mod.scsi_logging_level=5056': ignoring > > So I picked up the new initrd with the scsi_dh part and put directly > that option at insmod statement line for scsi_mod module in initrd > init file, creating another special grub.conf stanza for this initrd > See messages and output of dmesg with this parameter at the links below > > https://docs.google.com/open?id=0BwoPbcrMv8mvNzU1ZTNlY2UtY2E5Ni00NDdlLW > IyY2UtZmQ0Y2I4OTJmNTZi > and > https://docs.google.com/open?id=0BwoPbcrMv8mvZmUxNTNmNjgtOTZmMi00YTBiLT > kyZTktZWU0NTdjZWI4OWZm > > At the end of boot: > mpath1 (3600a0b80005012440000093e4a55cf33) dm-6 IBM,1814 FAStT > [size=3.4T][features=1 queue_if_no_path][hwhandler=1 rdac][rw] > \_ round-robin 0 [prio=0][active] > \_ 3:0:1:1 sdc 8:32 [active][undef] > \_ 4:0:1:1 sde 8:64 [active][undef] > \_ round-robin 0 [prio=0][enabled] > \_ 3:0:0:1 sdb 8:16 [active][undef] > \_ 4:0:0:1 sdd 8:48 [active][undef] > > Hope it helps you understanding better what doesn't go as expected.. > Thanks for your time Here are the messages without scsi_dh_rdac in initrd. Nov 23 17:32:56 testserver kernel: sdc:end_request: I/O error, dev sdb, sector 0 Nov 23 17:32:56 testserver kernel: Buffer I/O error on device sdb, logical block 0 Here are the messages with scsi_dh_rdac in initrd. Nov 29 07:16:46 testserver kernel: Buffer I/O error on device sdd, logical block 0 If you notice above, there is only one message in having driver in initrd. The messages " Buffer I/O error" is coming from file system layer. There is no way of silencing there errors in older kernels. These messages are harmless. The newer kernels use "BH_Quiet" flag to silence there error. You can check the newer kernel sources. Final note. It is always recommended to include the handlers in initrd because it will avoid I/Os to passive paths reducing the boot time. > > Gianluca > > -- > dm-devel mailing list > dm-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/dm-devel -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
