Cannot resize btrfs volume

Hello,

I added a new disk into our RAID5 array, it looks like this:

md2 : active raid5 sdd4[3] sde4[4] sda4[0] sdc4[2] sdb4[1]

      3767274240 blocks level 5, 64k chunk, algorithm 2 [5/5] [UUUUU]

# btrfs fi sh
Label: none  uuid: 5534d2e7-be31-49c7-8ab7-90c5ab8afe18
	Total devices 1 FS bytes used 2.24TB
	devid    3 size 2.63TB used 2.63TB path /dev/md2

# mount
...
/dev/md2 on /home type btrfs (rw,noatime,compress)

# btrfs filesystem resize max /home
Resize '/home' of 'max'
ERROR: unable to resize '/home'

# umount /home/
# btrfs filesystem resize max /dev/md2
Resize '/dev/md2' of 'max'
ERROR: unable to resize '/dev/md2'

# tail /var/log/messages
May  4 10:28:57 localhost kernel: resizer unable to find device 1

2.6.38-gentoo-r3, latest git btrfs-progs

Can you please advice what to do?

Thank you

Lubos

Hello again,

OK I found it (randomly) on the wiki:
btrfs filesystem resize 3:max /home

Seems like btrfs help is not up-to-date and the wiki is...

Thank you again

Lubos

Lubos Kolouch, Wed, 04 May 2011 08:31:30 +0000:

Hi,

several time ago I posted a patch which addressed this lack of documentation [1]. Unfortunately when I revised this patch I missed this chunk, and now Chris merged the last (uncompleted) revision.

So now I am publish a new patch which address this issue.

Chris, if you want you can pull it from

http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git

or browse it at "http://cassiopea.homelinux.net/git/?p=btrfs-progs-unstable.git;a=summary".

Below the patch.
Regards
G.Baroncelli

index 6f92f91..220bcbd 100644
@@ -147,7 +147,7 @@ Force a sync for the filesystem identified by
\fI<path>\fR.
 .\" Some wording are extracted by the resize2fs man page
 .\"
 
-\fBfilesystem resize\fR\fI [+/\-]<size>[gkm]|max <path>\fR
+\fBfilesystem resize\fR\fI [<devid>:][+/\-]<size>[gkm]|max <path>\fR
 Resize a filesystem identified by \fI<path>\fR.
 The \fI<size>\fR parameter specifies the new size of the filesystem.
 If the prefix \fI+\fR or \fI\-\fR is present the size is increased or

decreased
@@ -164,6 +164,9 @@ The \fBresize\fR command \fBdoes not\fR manipulate the size
partition. If you wish to enlarge/reduce a filesystem, you must make
sure you
can expand the partition before enlarging the filesystem and shrink the partition after reducing the size of the filesystem.
+
+<devid> is the ID of the device which was enlarged or which will be reduced.
+To know the ID of a device use the command \fBbtrfs filesystem show\fR.
.TP

\fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
@@ -188,7 +191,7 @@ Show the btrfs filesystem with some additional info. If no U
passed, \fBbtrfs\fR show info of all the btrfs filesystem. .TP

-\fBdevice balance\fR \fI<path>\fR
+\fBfilesystem balance\fR \fI<path>\fR
Balance the chunks of the filesystem identified by \fI<path>\fR across the devices.
.TP
@@ -199,6 +202,7 @@ Add device(s) to the filesystem identified by \fI<path>\fR.

\fBdevice delete\fR\fI <dev> [<dev>..] <path>\fR Remove device(s) from a filesystem identified by \fI<path>\fR.
+
.PP

.SH EXIT STATUS
----

[1] email "Re: [PATCH][btrfs progs] Update/clean up btrfs help and man page" on 10/9/2010