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Re: how to tell if raid1 array is REALLY working?

On Fri, 10 Dec 2004, Harland Christofferson wrote:

> >i forgot if you can mount a disk that is part of a raid1 array
> >separately 
> hc -- i have another machine w/ raid1 and i can mount /dev/hdc partitions 
> .. even can see data i put only on /dev/hda is mirrored.


> hc -- after i first noticed this problem earlier in the week, i repartitioned 
> /dev/hdc with cfdisk and reformatted the partitions. I relyed on 
> cfdisk managing the cylinder boundaries correctly and i think it 
> did. after reformatting, and before rebuilding the array,

dont use cfdisk ...

use plain ole fdisk ... it wont !@#$%^ like "smart" cfdisk does
since you have to tell "dumb" fdisk what exactly you want

> fdisk -l /dev/hdc showed the proper partitions ...


raid does NOT mirror(copy) partition info, so i'd point the finger
to cfdisk

> this happened when the 
> mirror was rebuilt. also, the file system type i selected when i 
> created the partitions was hex FD -- raid filesystem.

good .. mean you can work off one disk if all else is working right 
> >
> >your system will crash big time one day
> hc -- :O

it will show its head when the system disk managers start to use 
the upper disk area of the partition 

> >good ... --> look for the [UU]
> hc -- what does the [UU] mean? 

donnno .. 
"U" is good
"_" is very very bad
> hc -- obviously, my partition is faulty but how can i fix it? do 
> i have to repartition (again) and reformat (again)? this didn't seem 
> to help the first time.

depends how you did "it" the first time
	- you cannot format the partition separately

time to fdisk the sucker again

and since you have to "format /dev/md0" .. you have to move all yur
data off the raid disk onto something else, rebuild the raid box,
format it and restore your data

c ya

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