<div dir="ltr"><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Feb 10, 2016 at 3:59 PM, Sean McGinnis <span dir="ltr"><<a href="mailto:sean.mcginnis@gmx.com" target="_blank">sean.mcginnis@gmx.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span class="">On Wed, Feb 10, 2016 at 03:30:42PM -0700, John Griffith wrote:<br>
> On Tue, Feb 9, 2016 at 3:23 PM, Ildikó Váncsa <<a href="mailto:ildiko.vancsa@ericsson.com">ildiko.vancsa@ericsson.com</a>><br>
> wrote:<br>
><br>
> ><br>
</span><span class="">> This may still be in fact the easiest way to handle this. The only other<br>
> thing I am still somewhat torn on here is that maybe Nova should be doing<br>
> ref-counting WRT shared connections and NOT send the detach in that<br>
> scenario to begin with?<br>
><br>
> In the case of unique targets per-attach we already just "work", but if you<br>
> are using the same target/attachment on a compute node for multiple<br>
> instances, then you probably should keep track of that on the users end and<br>
> not remove it while in use. That seems like the more "correct" way to deal<br>
> with this, but maybe that's just me. Keep in mind we could also do the<br>
> same ref-counting on the Cinder side if we so choose.<br>
<br>
</span>This is where I've been pushing too. It seems odd to me that the storage<br>
domain should need to track how the volume is being used by the<br>
consumer. Whether it is attached to one instance, 100 instances, or the<br>
host just likes to keep it around as a pet, from the storage perspective<br>
I don't know why we should care.<br>
<br>
Looking beyond Nova usage, does Cinder now need to start tracking<br>
information about containers? Bare metal hosts? Apps that are associated<br>
with LUNs. It just seems like concepts that the storage component<br>
shouldn't need to know or care about.<br>
<br></blockquote><div class="gmail_default" style="font-family:monospace,monospace;display:inline"><br class=""></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline">Well said</div> <div class="gmail_default" style="font-family:monospace,monospace;display:inline">, I agree</div></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline"></div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
I know there's some history here and it may not be as easy as that. But<br>
just wanted to state my opinion that in an ideal world (which I<br>
recognize we don't live in) this should not be Cinder's concern.<br><br></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span class="">
><br>
> We talked about this at mid-cycle with the Nova team and I proposed<br>
> independent targets for each connection on Cinder's side. We can still do<br>
> that IMO but that doesn't seem to be a very popular idea.<br>
<br>
</span>John, I don't think folks are against this idea as a concept. I think<br>
the problem is I don't believe all storage vendors can support exposing<br>
new targets for the same volume for each attachment.<br></blockquote><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline"></div></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline">Ahh, well that's a very valid reason to take a different approach.</div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<span class="im"><br>
><br>
> My point here is just that it seems like there might be a way to fix this<br>
> without breaking compatibility in the API. Thoughts?<br>
<br>
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