replace one disk in isw RAID1 array

[Aaron Hanson]

Hi All -

This seems like it should be a very common procedure.  I've researched this a lot before bothering this list, I hope someone can comment. In short:

-- I've created a mirror with 2 disks; it works fine. 
-- I shut the system down, remove one disk and replace it with a blank disk.
-- Power up; array state is inconsistent.
-- New disk is 'sdb'.  I want to use 'dmraid' to rebuild the array with the new disk, but I get errors. The most significant error seems to be:
    "ERROR: isw: only one failed disk supported"
-- 'dmraid ' continues to report that there is only one device in the set; the request to rebuild with a new drive has clearly failed.

The complete steps with additional version information and output is below.  Thanks in advance for any suggestions.  I would really appreciate references to some tutorials with more 'dmraid' examples than shown in the man page too, if such a thing exists.

-Aaron

bash (try 'info') lib > uname -a 
Linux localhost 2.6.18-194.26.1.el5.1.0.f5app #1 SMP Fri Nov 19 19:38:18 PST 2010 x86_64 x86_64 x86_64 GNU/Linux
bash (try 'info') lib > dmraid --version                        
dmraid version:		1.0.0.rc16-3 (2010.11.12) 
dmraid library version:	1.0.0.rc16-3 (2010.11.12)
device-mapper version:	4.11.5
bash (try 'info') lib > dmraid -s                               
ERROR: isw: wrong number of devices in RAID set "isw_bdidaifdia_Raid1" [1/2] on /dev/sda
*** Group superset isw_bdidaifdia
--> *Inconsistent* Active Subset
name   : isw_bdidaifdia_Raid1
size   : 586062848
stride : 128
type   : mirror
status : inconsistent
subsets: 0
devs   : 1
spares : 0
bash (try 'info') lib > dmraid -r
/dev/sda: isw, "isw_bdidaifdia", GROUP, ok, 586072366 sectors, data@ 0
bash (try 'info') lib > dmraid -dR isw_bdidaifdia_Raid1 /dev/sdb
DEBUG: _find_set: searching isw_bdidaifdia
DEBUG: _find_set: not found isw_bdidaifdia
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: not found isw_bdidaifdia_Raid1
DEBUG: _find_set: not found isw_bdidaifdia_Raid1
ERROR: isw: wrong number of devices in RAID set "isw_bdidaifdia_Raid1" [1/2] on /dev/sda
DEBUG: set status of set "isw_bdidaifdia_Raid1" to 4
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: searching isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
DEBUG: _find_set: found isw_bdidaifdia_Raid1
ERROR: isw: only one failed disk supported
metadata fmt update failed

DEBUG: rebuild: raid "isw_bdidaifdia_Raid1" rebuild finished

DEBUG: freeing devices of RAID set "isw_bdidaifdia_Raid1"
DEBUG: freeing device "isw_bdidaifdia_Raid1", path "/dev/sda"
DEBUG: freeing device "(null)", path "/dev/sdb"
DEBUG: freeing devices of RAID set "isw_bdidaifdia"
DEBUG: freeing device "isw_bdidaifdia", path "/dev/sda"
DEBUG: freeing device "(null)", path "/dev/sdb"
bash (try 'info') lib > dmraid -s                               
ERROR: isw: wrong number of devices in RAID set "isw_bdidaifdia_Raid1" [1/2] on /dev/sda
*** Group superset isw_bdidaifdia
--> *Inconsistent* Active Subset
name   : isw_bdidaifdia_Raid1
size   : 586062848
stride : 128
type   : mirror
status : inconsistent
subsets: 0
devs   : 1
spares : 0