<div dir="ltr"><span style="font-family:arial,sans-serif;font-size:13px">Lars, </span><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">thankyou for the useful insight, I made some other observations and have a few questions below.</div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">cheers,<br>Ian </div><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">
On my list of test scenarios is to test with some newer Debian 8/testing/Jessie packages (8.4.4-1). </div><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">
But I really need to stick with Debian Stable in production, so even if this resolves the problem, I would like to have the 8.3.13 stack working on multiple Debian Stable servers. <br></div><div style="font-family:arial,sans-serif;font-size:13px">
<br></div><div style="font-family:arial,sans-serif;font-size:13px">Before I go testing other scenarios that I can't maintain in production, I'd like to try and get the 8.3 stack working. </div><div style="font-family:arial,sans-serif;font-size:13px">
<br></div><div style="font-family:arial,sans-serif;font-size:13px">Your second point on the max BIO size is interesting. I didn't notice, likely because I did not understand what it means. It led me to find </div><div style="font-family:arial,sans-serif;font-size:13px">
<a href="http://lists.linbit.com/pipermail/drbd-user/2011-August/016659.html" target="_blank">http://lists.linbit.com/pipermail/drbd-user/2011-August/016659.html</a> <br></div><div style="font-family:arial,sans-serif;font-size:13px">
<br></div><div style="font-family:arial,sans-serif;font-size:13px">suggesting again, some of these VPS hosts confuse the DRBD calculation for max BIO size. I saw the same Error using LVM on backup, so I might assume this BIO size stays the same even switching to LVM. </div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">Question 1: Is there any known way to workaround the max BIO size issue on the 8.3.X stack?</div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">From what I have quickly learned, it has something to do with maximum discards, and is a metadata attribute. </div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">In the 8.4 documentation (<a href="http://www.drbd.org/users-guide/re-drbdmeta.html" target="_blank">http://www.drbd.org/users-guide/re-drbdmeta.html</a>) I see this parameter during mdcreate</div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">--peer-max-bio-size=val (metadata versions v06, v07, and v08)</div><div style="font-family:arial,sans-serif;font-size:13px">
<br></div><div style="font-family:arial,sans-serif;font-size:13px">This feature is not appearing in 8.3. </div><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">
So, I am going to try and use 8.4 userland tools (which I can pull down from the Debian 8 repository on my Debian 7 box easily) and re-create my metadata on host backup with a --peer-max-bio=4096 and resolve this issue, and then switch back to 8.3 userland to interpret my resource configuration and interop with my kernels 8.3 modules (assuming mixing kernel module and userland 8.3/8.4 is not a good idea). </div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">Question 2: Do you think this metadata fix is the right direction? </div><div style="font-family:arial,sans-serif;font-size:13px">
<br></div><div style="font-family:arial,sans-serif;font-size:13px">Question 3:Is this 'I'm sure it has been fixed since' you are referring to? If not, is there a patch or such that I might easily be able to submit to Debian package maintainers upstream. </div>
<div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">cheers,<br>Ian</div><div class="" style="font-family:arial,sans-serif;font-size:13px"><div id=":so" class="" tabindex="0">
<img class="" src="https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif"></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Jul 16, 2014 at 12:00 PM, Lars Ellenberg <span dir="ltr"><<a href="mailto:lars.ellenberg@linbit.com" target="_blank">lars.ellenberg@linbit.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="">On Mon, Jul 14, 2014 at 02:46:01PM -0400, Ian MacDonald wrote:<br>
> I have two hosts configured as Primary-Secondary on Debian 7 (current<br>
> stable) and DRBD (debian packaged 8.3.13-2)<br>
<br>
</div>How about you upgrade your drbd module and userland.<br>
<div class=""><br>
> Jul 14 12:06:05 backup kernel: [22632331.366571] block drbd0: max BIO size<br>
> = 4294966784<br>
<br>
</div>That looks broken.<br>
I'm sure it has been fixed since.<br>
<span class="HOEnZb"><font color="#888888"><br>
Lars<br>
<br>
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: Lars Ellenberg<br>
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