<tt><font size=2>bruno@wolff.to wrote on 02/13/2014 11:34:56:<br>
<br>
> On Thu, Feb 13, 2014 at 09:38:53 -0500,<br>
> John.Florian@dart.biz wrote:<br>
> >I just had interesting (or incredibly stupid) idea concerning
the critical<br>
> >limitation of the live overlays where the host crashes with bus
errors<br>
> >when the temporary space for the COW is exhausted. Is it
possible to use<br>
> >trim/discard support to mitigate some of the unidirectional growth
for<br>
> >when files are deleted and/or overwritten? Conceptually
it seems like it<br>
> >is a good fit, but I've not investigated the practicality. Just
curious<br>
> >if this has been explored or if there are easily known reasons
why this<br>
> >wouldn't work.<br>
> <br>
> I don't think this will help. You aren't going to recover space from
the <br>
> base file system, because it never changes. As more an more packages
<br>
> are updated you are going to use more space in the overlay area. </font></tt>
<br>
<br><tt><font size=2>I figured as much otherwise somebody would have already
done this. But my web searches didn't seem to reveal anything so
I had to ask.</font></tt>
<br><tt><font size=2> <br>
> Portable flash drives are getting cheaper and you might consider getting
<br>
> one large enough for a normal install and use that instead of a live
image. <br>
> Depending on how much you are installing, a 64 GB flash drive is probably
<br>
> large enough.</font></tt>
<br>
<br><tt><font size=2>That won't help me where I'm looking at hundreds to
thousands of embedded nodes that have very specific use requirements for
being based on a live image. Using a live image makes them very resilient
to mutation/corruption</font></tt><font size=2 face="sans-serif"> and anybody
can simply reset the hardware and have a node back to its normal working
state. You can think of this setup behaving much like firmware, albeit
with a Fedora image. :-)</font>
<br>
<br><font size=2 face="sans-serif">I just have to ensure the workloads
can never cause the overlay to become exhausted, which is sometimes easier
said than done, which is why I asked.</font>
<br><font size=2 face="sans-serif"><br>
--<br>
John Florian</font>
<br>