Bug#646900: [multipath-tools] Errors when Boot On SAN (IBM DS4700)

[Guy Roussin]

Hi,

Thank you Frido for this gift of new year.
The boot delay has improved a lot and no more errors such as describe in
my bug report ...

Guy


Le 04/01/2012 12:06, Frido Roose a écrit :
> Hello,
>
> When adding a script "add_rdac_handler" with the contents below - which
> loads scsi_dh_rdac as soon as possible - to
> the /etc/initramfs-tools/scripts/init-top/ directory, the number of io
> errors after loading initrd has diminished (only a coupple of "read
> failed" messages but no more end_request I/O errors
> And more importantly, the boot delay has improved alot.
>
> The message log looks more sane, like:
>
> Jan  4 11:58:50 raiti kernel: Write protecting the kernel read-only
> data: 10240k
> Jan  4 11:58:50 raiti kernel: Freeing unused kernel memory: 1060k freed
> Jan  4 11:58:50 raiti kernel: Freeing unused kernel memory: 1788k freed
> Jan  4 11:58:50 raiti kernel: rdac: device handler registered
> Jan  4 11:58:50 raiti kernel: usb 1-1: new high speed USB device using
> ehci_hcd and address 2
> Jan  4 11:58:50 raiti kernel: device-mapper: multipath: version 1.2.0 loaded
> Jan  4 11:58:50 raiti kernel: device-mapper: multipath round-robin:
> version 1.0.0 loaded
> Jan  4 11:58:50 raiti kernel: udev[281]: starting version 164
> <snip>
> Jan  4 11:58:50 raiti kernel: scsi 0:0:0:0: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: scsi 0:0:0:0: rdac: LUN 0 (unowned)
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:0: [sda] 2097152 512-byte logical
> blocks: (1.07 GB/1.00 GiB)
> Jan  4 11:58:50 raiti kernel: scsi 0:0:0:1: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:0: [sda] Write Protect is off
> Jan  4 11:58:50 raiti kernel: scsi 0:0:0:1: rdac: LUN 1 (unowned)
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:0: [sda] Write cache: enabled,
> read cache: enabled, supports DPO and FUA
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:1: [sdb] 584888320 512-byte
> logical blocks: (299 GB/278 GiB)
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:1: [sdb] Write Protect is off
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:1: [sdb] Write cache: enabled,
> read cache: enabled, supports DPO and FUA
> Jan  4 11:58:50 raiti kernel: sda:Dev sda: unable to read RDB block 0
> Jan  4 11:58:50 raiti kernel: unable to read partition table
> Jan  4 11:58:50 raiti kernel: scsi 0:0:1:0: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: scsi 0:0:1:0: rdac: LUN 0 (owned)
> Jan  4 11:58:50 raiti kernel: sdb:Dev sdb: unable to read RDB block 0
> Jan  4 11:58:50 raiti kernel: unable to read partition table
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:0: [sda] Attached SCSI disk
> Jan  4 11:58:50 raiti kernel: sd 0:0:0:1: [sdb] Attached SCSI disk
> Jan  4 11:58:50 raiti kernel: scsi 0:0:1:1: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:0: [sdc] 2097152 512-byte logical
> blocks: (1.07 GB/1.00 GiB)
> Jan  4 11:58:50 raiti kernel: scsi 0:0:1:1: rdac: LUN 1 (owned)
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:1: [sdd] 584888320 512-byte
> logical blocks: (299 GB/278 GiB)
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:0: [sdc] Write Protect is off
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:0: [sdc] Write cache: enabled,
> read cache: enabled, supports DPO and FUA
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:1: [sdd] Write Protect is off
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:1: [sdd] Write cache: enabled,
> read cache: enabled, supports DPO and FUA
> Jan  4 11:58:50 raiti kernel: sdc: unknown partition table
> Jan  4 11:58:50 raiti kernel: sdd: unknown partition table
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:0: [sdc] Attached SCSI disk
> Jan  4 11:58:50 raiti kernel: sd 0:0:1:1: [sdd] Attached SCSI disk
> Jan  4 11:58:50 raiti kernel: scsi 1:0:0:0: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: scsi 1:0:0:0: rdac: LUN 0 (unowned)
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:0: [sde] 2097152 512-byte logical
> blocks: (1.07 GB/1.00 GiB)
> Jan  4 11:58:50 raiti kernel: scsi 1:0:0:1: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:0: [sde] Write Protect is off
> Jan  4 11:58:50 raiti kernel: scsi 1:0:0:1: rdac: LUN 1 (unowned)
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:0: [sde] Write cache: enabled,
> read cache: enabled, supports DPO and FUA
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:1: [sdf] 584888320 512-byte
> logical blocks: (299 GB/278 GiB)
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:1: [sdf] Write Protect is off
> Jan  4 11:58:50 raiti kernel: sde:Dev sde: unable to read RDB block 0
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:1: [sdf] Write cache: enabled,
> read cache: enabled, supports DPO and FUA
> Jan  4 11:58:50 raiti kernel: unable to read partition table
> Jan  4 11:58:50 raiti kernel: scsi 1:0:1:0: Direct-Access     IBM
>   1815      FAStT  0914 PQ: 0 ANSI: 5
> Jan  4 11:58:50 raiti kernel: sdf:
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:0: [sde] Attached SCSI disk
> Jan  4 11:58:50 raiti kernel: scsi 1:0:1:0: rdac: LUN 0 (owned)
> Jan  4 11:58:50 raiti kernel: Dev sdf: unable to read RDB block 0
> Jan  4 11:58:50 raiti kernel: unable to read partition table
> Jan  4 11:58:50 raiti kernel: sd 1:0:0:1: [sdf] Attached SCSI disk
> <snip>
>
> The device section of multipath.conf in initrd looks like:
> device {
>          vendor "IBM"
>          product "1815"
>          path_grouping_policy    group_by_prio
>          path_checker            rdac
>          checker                 rdac
>          hardware_handler "1 rdac"
>          prio                    rdac
>          failback                immediate
>          no_path_retry           queue
>      }
>
> root at server:# cat /etc/initramfs-tools/scripts/init-top/add_rdac_handler
> #!/bin/sh
>
> PREREQ=""
> prereqs()
> {
> echo "$PREREQ"
> }
> case $1 in
> # get pre-requisites
> prereqs)
> prereqs
> exit 0
> ;;
> esac
>
> modprobe scsi_dh_rdac
> modprobe dm_multipath
> modprobe dm_round_robin