[linux] mdraid vraagje

[Udo van den Heuvel]

On 16-10-2019 14:52, Paul Slootman wrote:
> On Wed 16 Oct 2019, Udo van den Heuvel wrote:
>>
>>     Number   Major   Minor   RaidDevice State
>>        5       8        2        0      active sync set-A   /dev/sda2
>>        4       8       18        1      active sync set-B   /dev/sdb2
>>        6       8       50        2      active sync set-A   /dev/sdd2
>>        7       8       34        3      active sync set-B   /dev/sdc2
>>
>>
>> De vraag is nu:
>> Zijn sda2 en sdb2 op elkaar gemirrord of zijn sda2 en sdd2 op elkaar
>> gemirrord? (alle set-A's horen bij elkaar of elke mirror heeft een A en
>> B zijde...)
> 
> sda2 en sdd2 zijn beide in "set-A". Die vormen dus samen de complete
> data. Idem voor sdb2 en sdc2.

Dank, daruit komt voort dat sda2 dan op sdb2 en/of sdc2 gemirrord is.
(want andere set)
(alle disken zijn even groot)

> Misschien is mdadm --examine /dev/sda2 enz. wel nuttig.


# mdadm --examine /dev/sda2
/dev/sda2:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : dae41afd:5974ffb7:756ed761:303c28c0
           Name : (none):1
  Creation Time : Wed Nov  2 15:22:21 2011
     Raid Level : raid10
   Raid Devices : 4

 Avail Dev Size : 3903928496 (1861.54 GiB 1998.81 GB)
     Array Size : 3903927296 (3723.08 GiB 3997.62 GB)
  Used Dev Size : 3903927296 (1861.54 GiB 1998.81 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1960 sectors, after=1200 sectors
          State : clean
    Device UUID : f2c5b1f7:0881ed04:21ec7ccc:810fdbfc

    Update Time : Wed Oct 16 15:13:51 2019
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : 63b9d4cb - correct
         Events : 901760

         Layout : near=2
     Chunk Size : 512K

   Device Role : Active device 0
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
# mdadm --examine /dev/sdb2
/dev/sdb2:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : dae41afd:5974ffb7:756ed761:303c28c0
           Name : (none):1
  Creation Time : Wed Nov  2 15:22:21 2011
     Raid Level : raid10
   Raid Devices : 4

 Avail Dev Size : 3903928496 (1861.54 GiB 1998.81 GB)
     Array Size : 3903927296 (3723.08 GiB 3997.62 GB)
  Used Dev Size : 3903927296 (1861.54 GiB 1998.81 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1960 sectors, after=1200 sectors
          State : clean
    Device UUID : b9f915a0:c5edabf4:80749836:2e35dce0

    Update Time : Wed Oct 16 15:14:07 2019
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : 49f9236a - correct
         Events : 901760

         Layout : near=2
     Chunk Size : 512K

   Device Role : Active device 1
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
# mdadm --examine /dev/sdc2
/dev/sdc2:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : dae41afd:5974ffb7:756ed761:303c28c0
           Name : (none):1
  Creation Time : Wed Nov  2 15:22:21 2011
     Raid Level : raid10
   Raid Devices : 4

 Avail Dev Size : 3903928496 (1861.54 GiB 1998.81 GB)
     Array Size : 3903927296 (3723.08 GiB 3997.62 GB)
  Used Dev Size : 3903927296 (1861.54 GiB 1998.81 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1960 sectors, after=1200 sectors
          State : clean
    Device UUID : 4759e689:2384a2ac:21af0aa3:733160ad

    Update Time : Wed Oct 16 15:14:07 2019
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : 24b6503f - correct
         Events : 901760

         Layout : near=2
     Chunk Size : 512K

   Device Role : Active device 3
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
# mdadm --examine /dev/sdd2
/dev/sdd2:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : dae41afd:5974ffb7:756ed761:303c28c0
           Name : (none):1
  Creation Time : Wed Nov  2 15:22:21 2011
     Raid Level : raid10
   Raid Devices : 4

 Avail Dev Size : 3903928496 (1861.54 GiB 1998.81 GB)
     Array Size : 3903927296 (3723.08 GiB 3997.62 GB)
  Used Dev Size : 3903927296 (1861.54 GiB 1998.81 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1768 sectors, after=1200 sectors
          State : clean
    Device UUID : c807a4ae:1f9c5965:8c5f1e41:068efd4a

    Update Time : Wed Oct 16 15:14:07 2019
  Bad Block Log : 512 entries available at offset 264 sectors
       Checksum : 3ddc2478 - correct
         Events : 901760

         Layout : near=2
     Chunk Size : 512K

   Device Role : Active device 2
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)