Cannot remove last disk group configuration copy

at the risk of stating the obvious, that dg doesn't look healthy!

eg: config copies on the 6 "new" disks (emcpower[q-v]) state=iofailed, Error: error=Disk read failure
That state tends to be seen when the dg has lost access to the disk and has gone to dgdisabled state, eg: in this technote:

TN 229701: What to do when "vxdisk list" shows status of 'online dgdisabled'
http://seer.entsupport.symantec.com/docs/229701.htm

The dg probably hasn't gone into a disabled state (yet) as you still have a good copy on the "old" disk emcpowerf (dumpdg06) -- are there any issues on the volumes themselves?

Would you be able to provide the output of vxprint -qthrg <dg> as Dev requested? ie:
# vxprint -qhtrg dumpdg

From the currently available output it looks like the system has lost access to the disk at some point (possibly temporarily, or at least long enough for it to not be able to get to its config copy), OR something has happened to the label/header/portion on the disk where the config copy was stored.

The disks and dg are still showing online, which is why it would be good to check the vxprint output before proceeding with anything to see what is going on with the actual volumes - also, are the volumes in use at the moment?

Thanks everyone for the valuable feedback. I am running VXVM 4.1MP3 on Centos 4.8

Just to clarify I need the disk group and it should not be destroyed. Below is the vxdisk list output. The DG in question is dumpdg and it has currently 7 disks out of which dumpdg06(old disk) is what I need to remove from the dumpdg.

# vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
emcpowerf    auto:cdsdisk    dumpdg06     dumpdg       online
emcpowerg    auto:cdsdisk    datadev01    datadg       online
emcpowerh    auto:cdsdisk    datadev02    datadg       online
emcpoweri    auto:cdsdisk    datadev03    datadg       online
emcpowerj    auto:cdsdisk    datadev04    datadg       online
emcpowerk    auto:cdsdisk    datadev05    datadg       online
emcpowerl    auto:cdsdisk    datadev06    datadg       online
emcpowerm    auto:cdsdisk    datadev07    datadg       online
emcpowern    auto:cdsdisk    datadev08    datadg       online
emcpowero    auto:cdsdisk    logdev01     datadg       online
emcpowerp    auto:cdsdisk    miscdev01    datadg       online
emcpowerq    auto:cdsdisk    dumpdg07     dumpdg       online
emcpowerr    auto:cdsdisk    dumpdg08     dumpdg       online
emcpowers    auto:cdsdisk    dumpdg09     dumpdg       online
emcpowert    auto:cdsdisk    dumpdg10     dumpdg       online
emcpoweru    auto:cdsdisk    dumpdg11     dumpdg       online
emcpowerv    auto:cdsdisk    dumpdg12     dumpdg       online
sdb          auto:none       -            -            online invalid
sdc          auto            -            -            error



# vxdg list dumpdg
Group:     dumpdg
dgid:      1211488732.22.hostname.com
import-id: 1024.29
flags:     cds
version:   120
alignment: 8192 (bytes)
ssb:            on
detach-policy: global
dg-fail-policy: dgdisable
copies:    nconfig=default nlog=default
config:    seqno=0.1113 permlen=1280 free=1267 templen=7 loglen=192
config disk emcpowerf copy 1 len=1280 state=clean online
config disk emcpowerq copy 1 len=1280 state=iofail failed
       config-tid=0.0 pending-tid=0.0
       Error: error=Disk read failure
config disk emcpowerr copy 1 len=1280 state=iofail failed
       config-tid=0.0 pending-tid=0.0
       Error: error=Disk read failure
config disk emcpowers copy 1 len=1280 state=iofail failed
       config-tid=0.0 pending-tid=0.0
       Error: error=Disk read failure
config disk emcpowert copy 1 len=1280 state=iofail failed
       config-tid=0.0 pending-tid=0.0
       Error: error=Disk read failure
config disk emcpoweru copy 1 len=1280 state=iofail failed
       config-tid=0.0 pending-tid=0.0
       Error: error=Disk read failure
config disk emcpowerv copy 1 len=1280 state=iofail failed
       config-tid=0.0 pending-tid=0.0
       Error: error=Disk read failure
log disk emcpowerf copy 1 len=192
log disk emcpowerq copy 1 len=192 disabled
log disk emcpowerr copy 1 len=192 disabled
log disk emcpowers copy 1 len=192
log disk emcpowert copy 1 len=192
log disk emcpoweru copy 1 len=192
log disk emcpowerv copy 1 len=192

As Herve mentioned, changing the number of configuration copies may help

If you have 5.0 or above the following technote may also assist
TN 303352: How to force VM to keep configuration database on a specific disk
http://seer.entsupport.symantec.com/docs/303352.htm

although ... in an earlier post you mentioned this was 4.1MP3 so perhaps not - ie: if the keepmeta attribute is not available in 4.1 then increasing the number of config copies is probably the best bet (to put copies on the new disks, so the old emc disk can be removed)

By default 4 (or 5? depending on version) copies are kept, so if you had 6 disks before, this could be why additional copies were not added to the new disks.

If still not sure / wish to look further before proceeding, the output Dev suggested would be helpful, as well as the following for each disk:
# vxdisk list <disk>
(ie: for all 7 disks)

If you are trying to remove the last disk from the disk group then it means that you are actually trying to delete the disk group and if that is the purpose then you should rather try the command "vxdg destroy dg01".

Also paste the output of the following command, if deletion of the DG is not your purpose:

vxdisk -o alldgs -e list
vxprint -qhtrg dg01


Regards,
Dev

Hello,
I think you want to remove last disk from a type of storage but not to destroy the diskgroup, because the volumes are on the other storage.
In this case maybe increase the number of copy in the diskgroup

Note the number of copies (attribute nconfig) :
vxdg list yourdg

increase this number :
vxedit set nconfig=5 yourdg

Remove  the disk from the dg :
vxdg -g yourdg rmdisk yourdisk

Decrease the number of copies:
vxedit set nconfig=5 yourdg

Regards,
Herve