1 Reply Latest reply on Jan 8, 2015 5:57 PM by allan_intel

    Raid1 creates using isw metadata instead of imsm.


      I have a new Dell Precision being setup to use RAID1 via the Intel RSTe.  This system is intended to be bootable from either drive is one fails.  The hardware is using UEFI boot mode with Secure Boot turned off.  There are two 3 TB drives installed, where the entire drives will be raided (not partitions).  The platform specs are listed as Intel Matrix Storage Manager Version


      When a RAID1 device is created via the Intel BIOS menu, the individual drives are identified as type "isw_raid_member" when booted into a live SystemRescueCD.


      root#  blkid
      /dev/sda:  TYPE="isw_raid_member"
      /dev/sdb:  TYPE="isw_raid_member"


      A similar request via lsblk shows that each device is also an isw raid member.


      GParted shows that the raid device is 606.8 GB, far less than an expected 2.7 TB that it should be.  And it appears to be using dmraid, rather than mdadm.


      Deleting the raid device using the Intel BIOS menu, then creating it manually via mdadm at the command line produces expected results for the raid size as shown below.


      root#  mdadm --create --verbose /dev/md127 /dev/sd[ab] --raid-devices=2 --metadata=imsm
      root#  mdadm --create --verbose /dev/md/Vol0 /dev/md127 --raid-devices=2 --level=1


      A block ID query still shows the devices as an ISW raid member.
      root#  blkid
      /dev/sda:  TYPE="isw_raid_member"
      /dev/sdb:  TYPE="isw_raid_member"


      However, the raid device now shows the expected size of 2.73 TB via GParted and via a mdadm query.  A query of the container device via mdadm shows it is using imsm metadata format.


      root#  mdadm --query --detail /dev/md126
      Container:  /dev/md127, member 0
      Raid Level:  raid1
      Array Size:  (2794.52 GiB  3000.59 GB)
      Raid Devices:  2
      State:  clean, resyncing


      root#  mdadm --query --detail /dev/md127
      Version:  imsm
      Raid Level:  container


      So my question is:  Why when creating the raid via the Intel BIOS did it create an older format ISW dmraid device, rather than the current IMSM mdadm raid device, that appears to be supported by the hardware and the firmware version?