Topic: Question regarding RAID on a virtualized SME Server

[edb]

Could someone tell me if there is anything wrong with my RAID setup based on the output below:
The config is stock from SME install.

[root@ ~]# lvdisplay
  /dev/hdc: open failed: No medium found
  --- Logical volume ---
  LV Name                /dev/main/root
  VG Name                main
  LV UUID                OBYURy-3fXb-8a4j-rYBR-2ZZA-UnDx-55rvt8
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                85.97 GB
  Current LE             2751
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/main/swap
  VG Name                main
  LV UUID                vEZJhf-Of36-9VDx-m36O-H13B-UVhD-zHSEeX
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                3.91 GB
  Current LE             125
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1

[root@ ~]# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sda1[0]
      104320 blocks [2/1] [U_]

md2 : active raid1 sda2[0]
      94261312 blocks [2/1] [U_]

unused devices: <none>

Just wondering if the U_ is a problem or if it is supposed to be that way and if not what to do to fix it.
Thanks

[edb]

More info ....

[root@ ~]# mdadm --detail /dev/md1
/dev/md1:
        Version : 0.90
  Creation Time : Fri Jan 13 10:40:33 2012
     Raid Level : raid1
     Array Size : 104320 (101.89 MiB 106.82 MB)
  Used Dev Size : 104320 (101.89 MiB 106.82 MB)
   Raid Devices : 2
  Total Devices : 1
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Tue Oct  6 04:02:41 2015
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           UUID : f1ba5bc7:8c3f7cb1:8d01fc9a:e5bec55a
         Events : 0.23310

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       0        0        1      removed

[root@ ~]# mdadm --detail /dev/md2
/dev/md2:
        Version : 0.90
  Creation Time : Fri Jan 13 10:40:34 2012
     Raid Level : raid1
     Array Size : 94261312 (89.89 GiB 96.52 GB)
  Used Dev Size : 94261312 (89.89 GiB 96.52 GB)
   Raid Devices : 2
  Total Devices : 1
Preferred Minor : 2
    Persistence : Superblock is persistent

    Update Time : Tue Oct  6 09:53:40 2015
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           UUID : 04246279:667dd5ce:7d2ab943:8bb35d0f
         Events : 0.73428664

    Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       0        0        1      removed

[Stefano]

if you install your SME as a virtual machine without any switch at boot time, it has (it's a feature) a sw raid1 in degraded mode..

it's harmless.. are you having any issue?

[edb]

Thanks Stefano ... no issues right now other than when I try to do a FLR (File Level Recovery) using Veeam Backup for Virtual Machines.
It is not a big deal just that I'm trying to find a reason as to why Veeam cannot mount the backed up VMDK file system and says:
Cannot mount sda1: "Unsupported Filesystem"
Cannot mount sda2: "Unsupported Filesystem"
I thought it could be related to the RAID being degraded.
If it is harmless then I will leave it alone.

[Daniel B.]

You can force it into a non degraded state:

Code: [Select]

mdadm --grow /dev/md0 --raid-devices=1 --force
mdadm --grow /dev/md1 --raid-devices=1 --force

But it'll probably won't change anything regarding Veeam, I guess it doesn't support Linux software RAID (or maybe LVM ?), as a degraded state shouldn't change anything for it

[edb]

Ok, thank you for your input Daniel.
I think you are probably correct in that it may just be a Veeam issue as you indicated.
I have Veeam support looking into it as we speak but they thus far are perplexed as to why it isn't working but trying to come up with something.
I was just taking a long shot in thinking it may be the software RAID.
Thanks again.

[edb]

Would there be any way that I could disable or drop the software RAID?
I found out from Veeam support that they do support LVM but not LVM on software RAID.
Since it is a VM I don't think it is necessary to have the RAID1 in degraded mode anyway but the installer does it by default so how would one go about removing the RAID without effecting the production server now.
I think if I can do that then the Veeam backup FLR will work properly to provide instant file level recovery.
Thanks

[Daniel B.]

You can add the argument raid=none at the boot prompt, which disable software RAID, except for /boot which is always created on a degraded /dev/md0
The other option is to use the advanced graphical installer (just when the CD boots) which lets you create your own custom partition scheme

[edb]

Thanks Daniel,

Since it cannot be disabled completely with the raid=none option I guess I will have to live with it until I install sme server 9x and use the advanced graphical installer as you said to try and setup my own partitions without RAID.
At least I know now in the event that I want to move in that direction.