04-24-2015 02:45 AM
Dear All,
I added a LUN to a specific volume and realised that I added it to the wrong volume. To remove the LUN the following command was run :
"vxdg -g dg rmdisk vsp-xx-xx"
I was then prompted to run the " -k" option to remove the disk.
However after re-running the command with the " -k" option :
"vxdg -g dg -k rmdisk vsp-xx-xx"
... the volume went into a disabled state.
Fortunately no data was lost once the "vxmend" was completed on the volume.
I would just like to know if this was to be expected when running the above with the " -k" option ?
Regards
Solved! Go to Solution.
04-25-2015 03:29 AM
Just to explain:
A diskgroup is a collection of disks (LUNs)
A volume is created from the pool of LUNS in a diskgroup
A filesystem is usually created on the volume.
So the process to extend a filesystem is:
So if you wanted to remove a LUN you added to extend a filesystem, you would do the reverse of some or all of these steps, so if you added to the wrong volume and the volume you wanted to add to was in the same diskgroup you would do JUST reverse of step 5 and if volume you wanted to add to was in a different diskgroup you would do the reverse of 5 and 4.
The reverse steps are:
5. Shrink filesystem using "vxresize"
4. Remove disk from diskgroup using "vxdg rmdisk"
3. Un-Initialise disk to remove public and private region using "vxdiskunsetup"
2. Remove disk from volume manager control using "vxdisk rm"
1. Remove disk from O/S
So you jumped straight to reverse step 2, without doing 5 and 4 first.
Note reverse steps 2 and 3 are not even normally done as if you remove disk from O/S, it doesn't need to have these steps done.
Mike
04-24-2015 08:39 AM
Hi,
It looks like you attempted to remove a disk/LUN from a diskgroup, though the disk was still being used as storage for a volume.
After using "-k" the the disk was removed, though the volume now has some storage mapped to using that disk. To remove a disk from a disk group, it should first be freed up from any volume use.
cheers
tony
04-25-2015 03:29 AM
Just to explain:
A diskgroup is a collection of disks (LUNs)
A volume is created from the pool of LUNS in a diskgroup
A filesystem is usually created on the volume.
So the process to extend a filesystem is:
So if you wanted to remove a LUN you added to extend a filesystem, you would do the reverse of some or all of these steps, so if you added to the wrong volume and the volume you wanted to add to was in the same diskgroup you would do JUST reverse of step 5 and if volume you wanted to add to was in a different diskgroup you would do the reverse of 5 and 4.
The reverse steps are:
5. Shrink filesystem using "vxresize"
4. Remove disk from diskgroup using "vxdg rmdisk"
3. Un-Initialise disk to remove public and private region using "vxdiskunsetup"
2. Remove disk from volume manager control using "vxdisk rm"
1. Remove disk from O/S
So you jumped straight to reverse step 2, without doing 5 and 4 first.
Note reverse steps 2 and 3 are not even normally done as if you remove disk from O/S, it doesn't need to have these steps done.
Mike
04-28-2015 02:14 AM
Oh dear!
I hope you have a backup of this volume...
Or else you might be able to find a good copy of diskgroup backup and restore diskgroup/volume with vxconfigrestore.
See this TN: http://www.symantec.com/docs/TECH201366
If all is fine after diskgroup restore, follow the 'reverse' steps in Mike's post.
05-06-2015 02:07 AM
Hi,
question 1: if -k is a good option for you:
Refer manual about vxdg -k rmdisk:
rmdisk Removes the specified disk or disks from a disk
group. It is not possible to remove the last disk
containing a valid disk group configuration or log
copy from its disk group.
Typically, the rmdisk operation fails if subdisk
records point to the named disk media records.
However, if the -k option is specified, the disk
media records are kept, although in a removed
state, and the subdisk records still point to
them. The subdisks, and any plexes that refer to
them, remain unusable until the disk is re-added
using the -k option to the adddisk operation.
VxVM disables volumes when all plexes become unus-
able.
so with -k option rmdisk, mean you will use -k option to add disk back:
if the -k option is specified, the disk
media records are kept, although in a removed
state, and the subdisk records still point to
them. The subdisks, and any plexes that refer to
them, remain unusable until the disk is re-added
using the -k option to the adddisk operation.
In your situation, -k is not needed.
question 2: volume disable:
VxVM disables volumes when all plexes become unus-
able.
if you like remove disk from dg , must make sure the disk is not used by any volume.
You can use vxeva to get that.
Regards