Topic: RAID configuration on install

[mercyh]

Good Morning,
I just want to clarify what happens by default on install with RAID on SME9. In past versions, if a system had 3 disks, the default install would be RAID1 with a hot spare. This means 2 disks would be mirrors and one disk would be empty and the raid would automatically mirror on the blank disk if one of the mirrored disks failed.

With the SME9 setup, am I correct that all three disks would be mirrors of each other?

Thanks,

Royce

[mercyh]

I found the answer to my question Here.

Three drives mirrored is not a bad idea. If the drive is running as a hot spare, it is still running so has the same mechanical wear as the other drives.

Why not have it mirrored so if one drive fails there is no rebuild time, and if two fail at the same time, there is still a working array....

[david000]

I've 2 x 1tb drives installed on my new dell box.

When I run the config raid check it says that only 1 drive is installed.

However the command line below hints that both are installed and working ?

++++++++++++++++++++++++++++++++++++++++++++
[root@sme-server ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[0]
      255936 blocks super 1.0 [2/1] [U_]

md1 : active raid1 sda2[0]
      976373568 blocks super 1.1 [2/1] [U_]
      bitmap: 8/8 pages [32KB], 65536KB chunk

unused devices: <none>
++++++++++++++++++++++++++++++++++++++++++++

Is there a way to confirm ?

Ta.

[mercyh]

Yours shows only one drive..

Mine has three drives in RAID1 with all three drives mirrored:

[root@mail ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sda1[0] sdc1[2] sdb1[1]
      255936 blocks super 1.0 [3/3] [UUU]

md1 : active raid1 sdc2[2] sda2[0] sdb2[1]
      487998272 blocks super 1.1 [3/3] [UUU]
      bitmap: 2/4 pages [8KB], 65536KB chunk

Some examples with how to read this file is HERE.


Do your drives show up in BIOS when the box boots? Is it possible that some of your SATA channels are disabled in BIOS?

[david000]

ah, I saw md0 and md1 and thought they were the drives. I'm new to linux...

I'll have a look at the bios on the box in question and read your link.

[mercyh]

I'm new to linux...

I think everyone has trouble understanding mdstat the first go around..

You may be new to Linux but you are picking this up very quickly..!