[Kimchi-devel] [RFC] create a vm on a lun directly

[Aline Manera]

On 03/17/2014 06:01 AM, Sheldon wrote:
> Now we have support iSCSI or SCSI pool.
> But we do not make use of the iSCSI or SCSI pool at present.
>
> Here we want to create volumes for VM in those pools.
> The best way to do it is on template level - and not on vm level
>
> For if we create a template just assign a iSCSI or SCSI pool, the user 
> still need to choose
> a volume for his VM.
>
> in the edit template page, we list the storage pool and the volume
> like:
> dir-pool-1
> nfs-pool-2
> iscsi-pool-1/lun-1
> iscsi-pool-1/lun-2
> iscsi-pool-1/lun-3
> scsi-pool-1/lun-1
> scsi-pool-1/lun-2
>
> when selecting the storage pool with type iSCSI or SCSI the user also 
> select the volume.
>
> The user can create a VM with this volume.
>
> But we should let user know it is dangerous to avoid user mistake when 
> he choose the volume.
>
> 1. Now we only use the volume to create the vm not support shareable 
> volume.
> use the same volume in multiples vms, a new install will overwrite the 
> current content.
> We can check the volume ref_cnt to avoid this.
>

As you mentioned below the LUN can be used outside Kimchi so check 
volume ref_cnt will not prevent the error.
I suggest to warn the user about the operation (same we did while 
creating a logical pool) and if he/she
confirm the operation we create the vm.

For example: when user selects a template with a specific LUN we display 
a confirmation window:

"This will cause lost of data in the LUN <lun-name>. Are you sure to 
continue?"

> 2. even this lun is not used buy vm, maybe the Adam has added a lun to 
> a VG or use it on other purpose
> Should we check the lun is is used external kimchi?
> If a lun is added to a VG, need to check it?
> If adam format a lun and create a files system on, need to check it?
> Or we just prompt the data on this volume will destroyed.
>
>