[[PageOutline]]

 * verbose log of [../]

 = mdadm -D /dev/md0 =
 * mitty@ubuntu-haa:~$ sudo mdadm -D /dev/md0
{{{
/dev/md0:
        Version : 00.90
  Creation Time : Thu Mar 24 17:31:36 2011
     Raid Level : raid1
     Array Size : 2047936 (2000.27 MiB 2097.09 MB)
  Used Dev Size : 2047936 (2000.27 MiB 2097.09 MB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Thu Mar 24 17:31:47 2011
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           UUID : 32578407:6f33f50b:893cf340:745f5dce (local to host ubuntu-haa)
         Events : 0.34

    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1
}}}

 = dpkg-reconfigure mdadm =
 * see also wiki:TipAndDoc/RAID#dpkg-reconfiguremdadm

 * mitty@ubuntu-haa:~$ sudo dpkg-reconfigure mdadm
{{{
  ┌──────────────────────────┤ Configuring mdadm ├─
  │                                                                          │
  │ If the kernel supports it (versions greater than 2.6.14), mdadm can      │
  │ periodically check the redundancy of MD arrays (RAIDs). This may be a    │
  │ resource-intensive process, depending on the local setup, but it could   │
  │ help prevent rare cases of data loss. Note that this is a read-only      │
  │ check unless errors are found; if errors are found, mdadm will try to    │
  │ correct them, which may result in write access to the media.             │
  │                                                                          │
  │ The default, if turned on, is to check on the first Sunday of every      │
  │ month at 01:06.                                                          │
  │                                                                          │
  │ Should mdadm run monthly redundancy checks of the MD arrays?             │
  │                                                                          │
  │                  [[<Yes>]]                     <No>                      │
  │                                                                          │
  └──────────────────────────────────────

(snip)

  ┌──────────────────────────┤ Configuring mdadm ├─
  │                                                                         │
  │ The MD (RAID) monitor daemon sends email notifications in response to   │
  │ important MD events (such as a disk failure).                           │
  │                                                                         │
  │ Enabling this option is recommended.                                    │
  │                                                                         │
  │ Do you want to start the MD monitoring daemon?                          │
  │                                                                         │
  │                  [[<Yes>]]                     <No>                     │
  │                                                                         │
  └──────────────────────────────────────

(snip)

   ┌─────────────────────────┤ Configuring mdadm ├──
   │ Please enter the email address of the user who should get the email   │
   │ notifications for important MD events.                                │
   │                                                                       │
   │ Recipient for email notifications:                                    │
   │                                                                       │
   │ root_________________________________________________________________ │
   │                                                                       │
   │                                <Ok>                                   │
   │                                                                       │
   └───────────────────────────────────────

(snip)

 ┌───────────────────────────┤ Configuring mdadm ├ 
 │                                                                           │
 │ If your root filesystem is on a RAID, and a disk is missing at boot, it   │
 │ can either boot with the degraded array, or hold the system at a          │
 │ recovery shell.                                                           │
 │                                                                           │
 │ Running a system with a degraded RAID could result in permanent data      │
 │ loss if it suffers another hardware fault.                                │
 │                                                                           │
 │ If you do not have access to the server console to use the recovery       │
 │ shell, you might answer "yes" to enable the system to boot unattended.    │
 │                                                                           │
 │ Do you want to boot your system if your RAID becomes degraded?            │
 │                                                                           │
 │                  [[<Yes>]]                     <No>                       │
 │                                                                           │
 └───────────────────────────────────────
}}}