Re: How can I recover data from little overwritten missing raid0 device?

[Goffredo Baroncelli <kreijack@libero.it>]

After a reboot you need to do

# btrfs device scan

in order to search all devices which may be involved in a multi devices setup 
(like RAID).

G.Baroncelli




On Sunday, 17 October, 2010, Chalet16 wrote:
> UPDATE: I'm currently  able to see and read/write some file in degraded mode
> but there're many file i can't read with input/output error too.
> 
> 
> On Sun, Oct 17, 2010 at 9:57 PM, Chalet16 <chalet16@gmail.com> wrote:
> > I had set up btrfs with 2 devices by using command this command sequence.
> > "mkfs.btrfs -m raid1 /dev/sda1
> > mount /dev/sda1 /mnt/data
> > btrfs-vol -a /dev/sdb1 /mnt/data
> > btrfs-vol -b /mnt/data"
> >
> > (I was think that it will do raid1 for both data and metadata but I 
currently
> > realised that it will do raid1 for metadata but raid0 for data.)
> >
> > But I forgot that I have mount /dev/sdb1 with TrueCrypt. After I restarted 
my
> > PC and try to mount both devices array again there was a message in dmesg 
said
> > "chalet16@server:~$ sudo mount /dev/sda1 /mnt/data
> > [ 2828.921406] device label btr2902 devid 1 transid 8829 
/dev/mapper/truecrypt1
> > [ 2828.931780] btrfs: failed to read the system array on dm-1
> > [ 2828.961330] btrfs: open_ctree failed"
> >
> > And when I ran btrfs-show it show that
> > "chalet16@server:~$ sudo btrfs-show
> > failed to read /dev/sr0
> > Label: btr2902  uuid: 5673597c-ff57-4a42-8fe3-ff793f476809
> >        Total devices 2 FS bytes used 706.75GB
> >        devid    1 size 930.00GB used 717.26GB path /dev/sda1
> >        *** Some devices missing
> > Btrfs Btrfs v0.19"
> > And when I run btrfsck on missing device
> > "chalet16@server:~$ sudo btrfsck /dev/sde1
> > No valid Btrfs found on /dev/sde1"
> >
> > So I would like to ask for help to recover data from this btrfs raid 
array. In
> > my opinion I think that TrueCrypt only overwrite a little location in 
device
> > because I haven't done anything with TrueCrypt device after that.
> >
> > Thanks
> > Chalet16
> >
> >
> > PS. I have recently known that TrueCrypt is in "Forbidden items" list in 
Fedora
> > wiki, but this is not really related to TrueCrypt so please don't ban me 
because
> > I had used TrueCrypt.
> >
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