RAID1 content under Windows OS

RAID1 content under Windows OS

[Álvaro López López]

I have been able to create a RAID 1 device in a Linux 2.6.36 system using mdadm command. 

Both disks had been formatted using mkdosfs in order to be mounted with type vfat. I also changed its label using cfdisk from "Linux" to the "W95 FAT32".

After mounting the RAID1 device MD0 in the filesystem, I copy some files inside the folder associated to the RAID1. I can see the contents when MD0 is mounted
inside Linux, not if disks are mounted separately.

Then, when I connect both disks to a Windows XP or 7 OS I cannot see any content inside them.

Is it possible to see the content? What can I do?

Thanks in advance,

Alvaro



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Re: RAID1 content under Windows OS

[David Brown]

On 21/02/12 19:50, Álvaro López López wrote:
> I have been able to create a RAID 1 device in a Linux 2.6.36 system
> using mdadm command.
>
> Both disks had been formatted using mkdosfs in order to be mounted
> with type vfat. I also changed its label using cfdisk from "Linux" to
> the "W95 FAT32".
>
> After mounting the RAID1 device MD0 in the filesystem, I copy some
> files inside the folder associated to the RAID1. I can see the
> contents when MD0 is mounted inside Linux, not if disks are mounted
> separately.
>
> Then, when I connect both disks to a Windows XP or 7 OS I cannot see
> any content inside them.
>
> Is it possible to see the content? What can I do?
>
> Thanks in advance,
>
> Alvaro
>

I think it will be the metadata format that is the problem - by default, 
mdadm creates arrays with format 1.2 that is 4K from the start of the 
partition.  But this will confuse windows (or anything else that tries 
to read the partition directly).  If you create the array with format 
1.0, the metadata is placed at the end of the partition and windows will 
not notice it, and will therefore it will be able to see the filesystem 
properly.

Of course, if you /change/ anything on the filesystem from within 
windows, you will completely screw the array.

mvh.,

David
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