[WBEL-users] Adding to RAID 1, only sees new partition as spare... {Scanned} {Scanned}

[Kirby C. Bohling]

On Wed, May 18, 2005 at 01:06:25PM -0700, Scott Silva wrote:
> Benjamin Smith wrote:
> 
> >It appears that it's simply not possible to "add" drives to a RAID 1 array. 
> >raidreconf does not support RAID 1. 
> >
> >I had to start from scratch, reinitialize the array with both drives, run 
> >mke2fs, and recopy the data back over from the original drive. It took 
> >another 17 hours to copy everything, (ugh) but it's all up and working fine 
> >now. 
> >
> >Thanks! 
> >
> >-Ben 
> >
> >On Tuesday 17 May 2005 15:15, Scott Silva wrote:
> >  
> >
> >>Benjamin Smith wrote:
> >>    
> >>
> >>>I have a server that does backups, and I want to replace an existing 160 
> >>>      
> >>>
> >GB 
> >  
> >
> >>>drive, with a RAID 1 300 GB array. 
> >>>
> >>>I don't have enough IDE slots to mount all at the same time. So, I 
> >>>      
> >>>
> >installed a 
> >  
> >
> >>>single 300 GB HDD, configured it as /dev/md0 RAID 1, made a filesystem, 
> >>>mounted, and copied all the data over. It's seen and mounts fine with all 
> >>>data present. 
> >>>
> >>>Now, I've removed the original 160 GB HDD, and put the other new 300 GB in 
> >>>it's place. 
> >>>
> >>>I've tried and tried, and I can't get the 2nd 300 GB drive to sync up to 
> >>>      
> >>>
> >the 
> >  
> >
> >>>first 300 GB drive. It keeps seeing it as a spare... 
> >>>
> >>>What am I missing? 
> >>>
> >>>1st 300 GB partn in array (with data on it) /dev/hdh1 
> >>>2nd 300 GB partn in array (seen as spare) /dev/hde1 
> >>>      
> >>>
> >>Did you properly partition the new drive as type fd (linux raid)?
> >>
> >>Maybe you should use mdadm. I have had better luck with it over raidtools.
> >>you would use ;
> >>
> >>sfdisk -d /dev/hdh |sfdisk /dev/hde
> >>
> >>to clone the partition data, then
> >>
> >>mdadm -a /dev/md0 /dev/hde1
> >>
> >>
> >>    
> >>
> I know you can create a raid1 array with only one drive and add the
> other drive later, because I have done it.
> 

That's really nice, show me a command that changes the number of
devices in a RAID device.  That is the crux of your problem.

I've read that you can create a RAID device, and tell it there are
two devices, and make one that fails immediatly (any old block
device will do the job as long as it appears to be large enough).
It will write the meta-data to the first block device so it looks
like it has two devices.  (Essentially, you are creating a mirror
with a device that fails immediatly, and then adding a new device
later).

I've never seen anyone actually do it.

	Thanks,
		Kirby