Fedora 13 dmraid partitions for Intel software RAID

LuKaZ · #1 11th July 2010, 07:39 AM

My hardware has Intel Software RAID, in Fedora 11 I used dmraid to support this configuration.

Now I installed F13 and the intel software RAID is supported by mdadm:

/dev/md127 is the md device (major number 9)

Code:

[01:08][root@amturing:~]# cat /proc/mdstat 
Personalities : [raid0] 
md127 : active raid0 sda[1] sdb[0]
      488391680 blocks super external:/md0/0 128k chunks
      
md0 : inactive sdb[1](S) sda[0](S)
      4514 blocks super external:imsm
       
unused devices: <none>

Let's check what says about md127:

Code:

[01:08][root@amturing:~]# mdadm --misc --detail /dev/md127
/dev/md127:
      Container : /dev/md0, member 0
     Raid Level : raid0
     Array Size : 488391680 (465.77 GiB 500.11 GB)
   Raid Devices : 2
  Total Devices : 2

          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

     Chunk Size : 128K


           UUID : dcaa4234:615dfb43:2ba439de:11e6c5e2
    Number   Major   Minor   RaidDevice State
       1       8        0        0      active sync   /dev/sda
       0       8       16        1      active sync   /dev/sdb

Confirming the same with udevadm:

Code:

[01:02][root@amturing:~]# udevadm info --query=property --name=/dev/md127
UDEV_LOG=3
DEVPATH=/devices/virtual/block/md127
MAJOR=9
MINOR=127
DEVNAME=/dev/md127
DEVTYPE=disk
SUBSYSTEM=block
MD_LEVEL=raid0
MD_DEVICES=2
MD_CONTAINER=/dev/md0
MD_MEMBER=0
MD_UUID=dcaa4234:615dfb43:2ba439de:11e6c5e2
ID_PART_TABLE_TYPE=dos
UDISKS_PRESENTATION_NOPOLICY=1
UDISKS_PARTITION_TABLE=1
UDISKS_PARTITION_TABLE_SCHEME=mbr
UDISKS_PARTITION_TABLE_COUNT=8
DEVLINKS=/dev/block/9:127 /dev/disk/by-id/md-uuid-dcaa4234:615dfb43:2ba439de:11e6c5e2

Effectively, /dev/md127 is the Intel Software RAID composed by /dev/sda and /dev/sdb. Just to show Intel SW Raid metadata in disks sda and sdb:

Code:

[22:59][root@amturing:~]# mdadm --misc --examine /dev/sda
/dev/sda:
          Magic : Intel Raid ISM Cfg Sig.
        Version : 1.0.00
    Orig Family : eac70f67
         Family : eac70f67
     Generation : 00000502
           UUID : 1b9ff023:c53ecf17:bef9aaa7:234b5413
       Checksum : f422ad1e correct
    MPB Sectors : 1
          Disks : 2
   RAID Devices : 1

  Disk00 Serial : 14FC3D00NJG3ZDYD
          State : active
             Id : 00000000
    Usable Size : 488392654 (232.88 GiB 250.06 GB)

[ARRAY]:
           UUID : dcaa4234:615dfb43:2ba439de:11e6c5e2
     RAID Level : 0
        Members : 2
      This Slot : 0
     Array Size : 976783360 (465.77 GiB 500.11 GB)
   Per Dev Size : 488391944 (232.88 GiB 250.06 GB)
  Sector Offset : 0
    Num Stripes : 1907780
     Chunk Size : 128 KiB
       Reserved : 0
  Migrate State : idle
      Map State : normal
    Dirty State : clean

  Disk01 Serial : 14FC3D00NJG3ZJ6D
          State : active
             Id : 00040000
    Usable Size : 488392654 (232.88 GiB 250.06 GB)

Now my problem is the following. when I add partitions to this RAID 0 (/dev/md127) with fdisk I have no problems. In this example I just added p8:

Code:

[01:12][root@amturing:~]# fdisk -l /dev/md127

Disk /dev/md127: 500.1 GB, 500113080320 bytes
2 heads, 4 sectors/track, 122097920 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 131072 bytes / 262144 bytes
Disk identifier: 0xe0000000

      Device Boot      Start         End      Blocks   Id  System
/dev/md127p1               8       28114      112423+  de  Dell Utility
Partition 1 does not end on cylinder boundary.
Partition 1 does not start on physical sector boundary.
/dev/md127p2           28161      552448     2097152    7  HPFS/NTFS
Partition 2 does not end on cylinder boundary.
/dev/md127p3   *      552449    13354032    51206333    7  HPFS/NTFS
Partition 3 does not end on cylinder boundary.
/dev/md127p4        13354049   122097920   434975488    5  Extended
Partition 4 does not end on cylinder boundary.
/dev/md127p5        13354177    13482176      512000   83  Linux
/dev/md127p6        13482241    39082240   102400000   8e  Linux LVM
/dev/md127p7        39082497    52189696    52428800   8e  Linux LVM
/dev/md127p8        52189953    58743552    26214400   8e  Linux LVM

/dev/md128 should be mapped with the device file /dev/md127p8:

Code:

[01:22][root@amturing:~]# ls -l /dev/md*
brw-rw----. 1 root disk   9,   0 Jul 10 19:37 /dev/md0
brw-rw----. 1 root disk   9, 127 Jul 10 20:36 /dev/md127
brw-rw----. 1 root disk 259,   0 Jul 10 11:34 /dev/md127p1
brw-rw----. 1 root disk 259,   1 Jul 10 11:34 /dev/md127p2
brw-rw----. 1 root disk 259,   2 Jul 10 11:34 /dev/md127p3
brw-rw----. 1 root disk 259,   3 Jul 10 11:33 /dev/md127p4
brw-rw----. 1 root disk 259,   4 Jul 10 11:34 /dev/md127p5
brw-rw----. 1 root disk 259,   5 Jul 10 11:34 /dev/md127p6
brw-rw----. 1 root disk 259,   6 Jul 10 11:34 /dev/md127p7

/dev/md:
total 4 /dev/md127p8:
-rw-------. 1 root root 114 Jul 10 06:33 md-device-map

My question is how I generate the device file /dev/md127p8, I tried using kpartx and partprobe but with the following errors:

Code:

[01:25][root@amturing:~]# kpartx /dev/md127
md127p1 : 0 224847 /dev/md127 63
md127p2 : 0 4194304 /dev/md127 225280
md127p3 : 0 102412666 /dev/md127 4419584
md127p4 : 0 2 /dev/md127 106832384
md127p5 : 0 1024000 /dev/md127 106833408
md127p6 : 0 204800000 /dev/md127 107857920
md127p7 : 0 104857600 /dev/md127 312659968
md127p8 : 0 52428800 /dev/md127 417519616
[01:25][root@amturing:~]# kpartx -a /dev/md127
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p1
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p2
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p3
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p4
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p5
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p6
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p7
device-mapper: reload ioctl failed: Invalid argument
create/reload failed on md127p8

Code:

[01:25][root@amturing:~]# partprobe /dev/md127
Warning: WARNING: the kernel failed to re-read the partition table on /dev/md127 (Device or resource busy).  As a result, it may not reflect all of your changes until after reboot.

If I reboot then the device file is created, but in Fedora 11 using dmraid und kpartx I am able to generate the device file.

I would like to know how to create the device file without rebooting

Thanks

LuKaZ · #2 12th July 2010, 04:09 AM

What I've found up to now is that kpartx is a tool to work only with device-mapper. In my case I'm using mdadm, so I think the only way to create the device file for the partition is using mdamd. Also I found that starting with mdadm 3.0 support for the Intel Matrix Storage Manager was added in userspace.

So kpartx shouldn't work with /dev/md127 because this is not a device-mapper device.

But the question remains, how to create device file /dev/md127p8 without reboot?