> -----Original Message----- > From: Gianluca Cecchi [mailto:gianluca.cecchi@xxxxxxxxx] > Sent: Monday, November 28, 2011 10:05 AM > To: device-mapper development > Subject: Re: info on enabling only one path with rdac and > DS4700 > > On Mon, Nov 28, 2011 at 3:46 PM, Moger, Babu wrote: > >> 3) Based on messages during failover, is it true that I can avoid > >> explicitly put scsi_dh in initrd? > >> If I create initrd this way: > >> mkinitrd /boot/initrd-$(uname -r)-scsi_dh.img $(uname -r) -- > >> preload=scsi_dh_rdac > >> I get this difference: > >> [root@testserver ~]# diff /tmp/new/init /tmp/current/init > >> 44,51d43 > >> < echo "Loading scsi_mod.ko module" > >> < insmod /lib/scsi_mod.ko > >> < echo "Loading sd_mod.ko module" > >> < insmod /lib/sd_mod.ko > >> < echo "Loading scsi_dh.ko module" > >> < insmod /lib/scsi_dh.ko > >> < echo "Loading scsi_dh_rdac.ko module" > >> < insmod /lib/scsi_dh_rdac.ko > >> 62a55,58 > >> > echo "Loading scsi_mod.ko module" > >> > insmod /lib/scsi_mod.ko > >> > echo "Loading sd_mod.ko module" > >> > insmod /lib/sd_mod.ko > >> > >> or will it help in any way? > > > > Having scsi_dh_rdac in initrd will help to get rid of the initial I/O > errors you are seeing. > > > > Actually not.... see screen shots of console start at > https://docs.google.com/open?id=0BwoPbcrMv8mvMWRlYmVhM2MtY2JkYi00ZDMzLW > IxMWMtMDM0YzZjMWU0NGE1 > and > https://docs.google.com/open?id=0BwoPbcrMv8mvM2RjMDg1MWUtYzVmZC00OTA1LT > ljNjAtZGZmMjM5NDlhYTI4 > and also dmesg giving for example for sdb and sdc: Looks like there is something else going on here. > > scsi 3:0:0:1: rdac: LUN 1 (unowned) This is when handler is loaded. Looks like your passive paths were detected first. >From now on, I/Os coming on to sdb will be silenced and will not got to target. That is not happening. What is the kernel level. I remember there was an issue. It was fixed later by this commit.. http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=5a36756b8b3d7178d9c101d1e2a7a83fd7b17706 > sdb : very big device. try to use READ CAPACITY(16). > SCSI device sdb: 7320494080 512-byte hdwr sectors (3748093 MB) > sdb: Write Protect is off > sdb: Mode Sense: 77 00 10 08 > SCSI device sdb: drive cache: write back w/ FUA > sdb : very big device. try to use READ CAPACITY(16). > SCSI device sdb: 7320494080 512-byte hdwr sectors (3748093 MB) > sdb: Write Protect is off > sdb: Mode Sense: 77 00 10 08 > SCSI device sdb: drive cache: write back w/ FUA > sdb:<3>Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > Dev sdb: unable to read RDB block 0 > Buffer I/O error on device sdb, logical block 0 > Buffer I/O error on device sdb, logical block 0 > unable to read partition table > sd 3:0:0:1: Attached scsi disk sdb > Vendor: IBM Model: 1814 FAStT Rev: 0916 > Type: Direct-Access ANSI SCSI revision: 05 > scsi 3:0:1:1: rdac: LUN 1 (owned) > scsi 3:0:1:1: rdac: LUN 1 (owned) > sdc : very big device. try to use READ CAPACITY(16). > SCSI device sdc: 7320494080 512-byte hdwr sectors (3748093 MB) > sdc: Write Protect is off > sdc: Mode Sense: 77 00 10 08 > SCSI device sdc: drive cache: write back w/ FUA > sdc : very big device. try to use READ CAPACITY(16). > SCSI device sdc: 7320494080 512-byte hdwr sectors (3748093 MB) > sdc: Write Protect is off > sdc: Mode Sense: 77 00 10 08 > SCSI device sdc: drive cache: write back w/ FUA > sdc: unknown partition table > sd 3:0:1:1: Attached scsi disk sdc > ... > GSI 23 sharing vector 0x72 and IRQ 23 > ACPI: PCI Interrupt 0000:04:00.0[A] -> GSI 17 (level, low) -> IRQ 114 > eth0: Broadcom NetXtreme II BCM5708 1000Base-SX (B2) PCI-X 64-bit > 133MHz found at mem da000000, IRQ 114, node addr 00215e2fd0e2 > ACPI: PCI Interrupt 0000:06:00.0[A] -> GSI 19 (level, low) -> IRQ 90 > eth1: Broadcom NetXtreme II BCM5708 1000Base-SX (B2) PCI-X 64-bit > 133MHz found at mem d8000000, IRQ 90, node addr 00215e2fd0e4 > printk: 69 messages suppressed. > Buffer I/O error on device sdb, logical block 0 > ... > md: Autodetecting RAID arrays. > md: autorun ... > md: ... autorun DONE. > device-mapper: multipath: version 1.0.6 loaded > device-mapper: multipath: Using scsi_dh module scsi_dh_rdac for > failover/failback and device management. > device-mapper: multipath round-robin: version 1.0.0 loaded > printk: 4 messages suppressed. > Buffer I/O error on device sdb, logical block 915061759 > ... > > So if I have to get yet the I/O errors, having no advantage, I'd > prefer to stay stick with the default initrd... > > -- > 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
