drive dropped from RAID5 set after reboot

[blu at vl.com (Tom Metro)]

Matthew Gillen wrote:
>> So it looks like the drives in the RAID array weren't being monitored by
>> smartd. ... Seems it doesn't like these SATA drives.
> 
> The older libata doesn't provide most of the ioctls needed for smart/hdparm
> on SATA drives...

As noted, this system is running the "bleeding edge" Ubuntu Fiesty (akin 
to Debian Unstable), so it ought to be the latest. I'll investigate 
tomorrow and post a follow-up.


> Does it's partition type match the others that did get detected?

Yes.

# sfdisk -l

  Disk /dev/sda: 38913 cylinders, 255 heads, 63 sectors/track
  Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

     Device Boot Start     End   #cyls    #blocks   Id  System
  /dev/sda1          0+  38912   38913- 312568641   fd  Linux raid 
autodetect
  /dev/sda2          0       -       0          0    0  Empty
  /dev/sda3          0       -       0          0    0  Empty
  /dev/sda4          0       -       0          0    0  Empty

  Disk /dev/sdb: 38913 cylinders, 255 heads, 63 sectors/track
  Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

     Device Boot Start     End   #cyls    #blocks   Id  System
  /dev/sdb1          0+  38912   38913- 312568641   fd  Linux raid 
autodetect
  /dev/sdb2          0       -       0          0    0  Empty
  /dev/sdb3          0       -       0          0    0  Empty
  /dev/sdb4          0       -       0          0    0  Empty

  Disk /dev/sdc: 38913 cylinders, 255 heads, 63 sectors/track
  Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

     Device Boot Start     End   #cyls    #blocks   Id  System
  /dev/sdc1          0+  38912   38913- 312568641   fd  Linux raid 
autodetect
  /dev/sdc2          0       -       0          0    0  Empty
  /dev/sdc3          0       -       0          0    0  Empty
  /dev/sdc4          0       -       0          0    0  Empty

  Disk /dev/sdd: 38913 cylinders, 255 heads, 63 sectors/track
  Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

     Device Boot Start     End   #cyls    #blocks   Id  System
  /dev/sdd1          0+  38912   38913- 312568641   fd  Linux raid 
autodetect
  /dev/sdd2          0       -       0          0    0  Empty
  /dev/sdd3          0       -       0          0    0  Empty
  /dev/sdd4          0       -       0          0    0  Empty
  ...


> ...if the partition types for some of the drives were set
> to RAID-autodetect and one wasn't, I could see how it might reconstruct it
> partially.

Agreed. Good thing to check.

But all the drives were setup with the same commands, with the exception 
that /dev/sda1 and /dev/sdb1 were originally part of a RAID0 array, and 
had their superblock zeroed before being added to the RAID5 array.

However, /dev/sdb1 was part of the RAID5 array since it was created and 
has survived a few reboots without disappearing before.


> If that's not the root cause, I haven't the slightest idea what
> could be...

Thanks for the suggestions. Maybe I'll file a bug in case someone else 
runs across the same symptom. (I've been getting quite familiar with 
Ubuntu's bug tracker lately. :-) )

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/

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