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
> 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
> 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?
"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