[linux-lvm] ocf:lvm2:VolumeGroup RA Question

[Marc Smith]

Okay, after testing, I realize we check for the status of an LV so we
can deactivate that when stopping the resource, and its used as the
state for the RA. I'm fine with making a "dummy" LV upon VG creation
in my setup, so I'm all good, disregard.


Thanks,

Marc



On Sun, Sep 25, 2016 at 12:10 PM, Marc Smith <marc.smith at mcc.edu> wrote:
> Hi,
>
> I'm using the "VolumeGroup" RA that comes with LVM2. On the machines
> I'm testing with, we are currently using version 2_02_129 of LVM2.
>
> My question is regarding this function in the VolumeGroup RA:
>
> --snip--
> VolumeGroup_status() {
>
>     VGOUT=`vgdisplay -v $OCF_RESKEY_volgrpname 2>&1` || exit $OCF_ERR_GENERIC
>     echo "$VGOUT" | grep -i 'Status[ \t]*available' >/dev/null
>     rc=$?
>
>     if [ $rc -eq 0 ]; then
>     ocf_log debug "LVM Volume Group $OCF_RESKEY_volgrpname is
> available (started)"
>     else
>     ocf_log debug "LVM Volume Group $OCF_RESKEY_volgrpname is not
> available (stopped)"
>     return $OCF_NOT_RUNNING
>     fi
>
>     if echo "$VGOUT" | grep -i 'Access.*read/write' >/dev/null; then
>     ocf_log debug "Volume $OCF_RESKEY_volgrpname is available
> read/write (running)"
>     else
>     ocf_log debug "Volume $OCF_RESKEY_volgrpname is available
> read-only (running)"
>     fi
>
>     return $OCF_SUCCESS
> }
> --snip--
>
> And what prompted me to question this function, is I noticed that
> unless an LV is created on my VG, this function doesn't return
> OCF_SUCCESS.
>
> When looking at the vgdisplay output in the first few lines of the
> function, there are several different output lines that contains the
> string "Status" (assuming the command exists successfully):
>
> # vgdisplay -v vmdk5 2>&1 | grep Status
>   VG Status             resizable
>   LV Status              available
>   PV Status             allocatable
>
> In the next line of the function where we grep for "Status" we don't
> specify a specific line (eg, "VG Status", "LV Status", or "PV
> Status").
>
> My question is this: Is the intention that we only return OCF_SUCCESS
> if a LV is available? In my setup, I'd like the resource to start/run
> properly without having any LV created. Any harm in updating the RA to
> look for "VG Status" and return success if it finds "resizable" -- I'm
> not sure what the other status strings might be? Is "available" valid
> for that line as well?
>
>
> Thanks for your time.
>
>
> --Marc