[luau] NFS ate my raid superblock

[Myles Uyema]

Yes, you'll want to watch your kernel messages as you boot up to see if 
it is an FS detection issue or a RAID detection issue.  Having yourself 
on striped RAID-0 though leaves your guard low and your chin up.

Here's the Kernel bootup portion of the RAID log.  It successfully 
detects an MD0 and MD1 device, which are written as special labels on 
each drive/partition that participates in a persistent raid.

md: raid1 personality registered as nr 3
md: Autodetecting RAID arrays.
 [events: 0000005a]
 [events: 0000005a]
 [events: 0000005a]
 [events: 0000005a]
md: autorun ...
md: considering sdc2 ...
md:  adding sdc2 ...
md:  adding sdb2 ...
md: created md1
md: bind<sdb2,1>
md: bind<sdc2,2>
md: running: <sdc2><sdb2>
md: sdc2's event counter: 0000005a
md: sdb2's event counter: 0000005a
md: RAID level 1 does not need chunksize! Continuing anyway.
md1: max total readahead window set to 508k
md1: 1 data-disks, max readahead per data-disk: 508k
raid1: device sdc2 operational as mirror 1
raid1: device sdb2 operational as mirror 0
raid1: raid set md1 active with 2 out of 2 mirrors
md: updating md1 RAID superblock on device
md: sdc2 [events: 0000005b]<6>(write) sdc2's sb offset: 17639296
md: sdb2 [events: 0000005b]<6>(write) sdb2's sb offset: 17639296
md: considering sdc1 ...
md:  adding sdc1 ...
md:  adding sdb1 ...
md: created md0
md: bind<sdb1,1>
md: bind<sdc1,2>
md: running: <sdc1><sdb1>
md: sdc1's event counter: 0000005a
md: sdb1's event counter: 0000005a
md: RAID level 1 does not need chunksize! Continuing anyway.
md0: max total readahead window set to 508k
md0: 1 data-disks, max readahead per data-disk: 508k
raid1: device sdc1 operational as mirror 1
raid1: device sdb1 operational as mirror 0
raid1: raid set md0 active with 2 out of 2 mirrors
md: updating md0 RAID superblock on device
md: sdc1 [events: 0000005b]<6>(write) sdc1's sb offset: 48064
md: sdb1 [events: 0000005b]<6>(write) sdb1's sb offset: 48064
md: ... autorun DONE.



On Wed, 20 Nov 2002, Eric Hattemer wrote:

> Wow, thanks a bunch.  Its 1 AM, and I had too much homework to try to fix
> this today, but I'll see if I can work on it tomorrow or later this week.  I
> hope I can remember my block size.
> 
> -Eric Hattemer
> ----- Original Message -----
> From: "Warren Togami" <warren at togami.com>
> To: <luau at videl.ics.hawaii.edu>
> Sent: Wednesday, November 20, 2002 12:45 AM
> Subject: Re: [luau] NFS ate my raid superblock
> 
> 
> > Below is the reply from Gregory Leblanc, maintainer of the Linux RAID
> HOWTO and active in a few other important projects.
> >
> 
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