Hi all, I'm having some issues. I'm a little confused, so I was checking our servers today and saw something strange. cat /proc/mdstat shows that 1 device md0 is inactive. I'm not really sure why. id did a bit more digging and testing using smartctl and it says that the device /dev/sdg (part of md0) is failing, estimated to fail within 24 hrs. but if i do df -h it doesn't even show md0, and was talking to a friend and we disagreed. I believe that based on what smrtctl says the drive is failing but not failed yet. he doesn't think its a problem with the drive. do you have any thoughts on this? and why would the device (md0) suddenly be inactive but still show 2 working devices (sdg, sdh)?

(proc/mdstat)
[root@csdatastandby3 bin]# cat /proc/mdstat
Personalities : [raid1] [raid10]
md125 : active raid10 sdf1[5] sdc1[2] sde1[4] sda1[0] sdb1[1] sdd1[3]
      11720655360 blocks super 1.2 512K chunks 2 near-copies [6/6] [UUUUUU]
     
md126 : active raid1 sdg[1] sdh[0]
      463992832 blocks super external:/md0/0 [2/2] [UU]
     
md0 : inactive sdh[1](S) sdg[0](S)
      6306 blocks super external:imsm
      
unused devices: <none>
[root@csdatastandby3 bin]#


(smartctl)
[root@csdatastandby3 bin]# smartctl -H /dev/sdg
smartctl 5.43 2012-06-30 r3573 [x86_64-linux-2.6.32-431.17.1.el6.x86_64] (local build)
Copyright (C) 2002-12 by Bruce Allen, http://smartmontools.sourceforge.net

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: FAILED!
Drive failure expected in less than 24 hours. SAVE ALL DATA.
Failed Attributes:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  5 Reallocated_Sector_Ct   0x0033   002   002   036    Pre-fail  Always   FAILING_NOW 32288

[root@csdatastandby3 bin]#

(df -h)
[root@csdatastandby3 bin]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/md126p4    404G  4.3G  379G   2% /
tmpfs            16G  172K   16G   1% /dev/shm
/dev/md126p2    936M   74M  815M   9% /boot
/dev/md126p1    350M  272K  350M   1% /boot/efi
/dev/md125       11T  4.2T  6.1T  41% /data
[root@csdatastandby3 bin]#


(mdadm -D /dev/md0
[root@csdatastandby3 bin]# mdadm -D /dev/md0
/dev/md0:
        Version : imsm
     Raid Level : container
  Total Devices : 2

Working Devices : 2


           UUID : 32c1fbb7:4479296b:53c02d9b:666a08f6
  Member Arrays : /dev/md/Volume0

    Number   Major   Minor   RaidDevice

       0       8       96        -        /dev/sdg
       1       8      112        -        /dev/sdh
[root@csdatastandby3 bin]#


thanks


-dustink