PANIC: VM_PAGE_UNWIRE invalid wire count: 0

[ryusoma]

hello all-

I have had v8.3.0-RELEASE-p1-x64 installed as an upgrade over a previous version, and running successfully for a couple months now until yesterday. During a routine scheduled scrub the system produced a panic, and I have now rebooted twice to the same problem.

the error reads:

panic: vm_page_unwire: invalid wire count: 0
cpuid = 0
KDB" enter: panic
[thread pid 0 tid 100109 ]
Stopped at kdb_enter+0x3b: movq $0,0x74cfa2(%rip)


The system is assigned 4Gb RAM and dual cores of Core2Quad on ESX 5.1; I've had no issues with the virtualized environment before this panic event.
Any suggestions for repair and recovery? What is the status of the disks assigned to this system?

 

[cyberjock]

No comment. There's plenty of reasons why VMs are not recommended for FreeNAS in production. That's why your previous post was ignored. We're so sick of trying to explain it we've given up.

I have no idea if that was the cause, but you definitely have a problem now. Additionally, I have no recommendations how to fix it, if your data is safe, or how you might proceed. I'd try a new USB stick and see what happens.

Additionally, you've made a grave mistake by using only 4GB of RAM if you are using ZFS.

 

[ryusoma]

No comment. There's plenty of reasons why VMs are not recommended for FreeNAS in production. That's why your previous post was ignored. We're so sick of trying to explain it we've given up.

I have no idea if that was the cause, but you definitely have a problem now. Additionally, I have no recommendations how to fix it, if your data is safe, or how you might proceed. I'd try a new USB stick and see what happens.

Additionally, you've made a grave mistake by using only 4GB of RAM if you are using ZFS.

So..

my question about upgrading a few months ago went unanswered because you don't like the question. Thankfully I was able to resolve the issue myself. And I see no reference to virtualization anywhere in the FAQ or wiki.. except in that FreeBSD can be virtualized and several of your links even refer to ZFS use in VirtualBox. And your own documentation on this site says only that ZFS can be used with less than 8Gb of RAM but performance may be reduced; not 4Gb of RAM is a "grave mistake".

So my previous valid and simple technical question was ignored because you can't be bothered.. and now that I do appear to have an actual error, you have no solution, no recommendation, no troubleshooting path to follow to validate the issue; the only reason for your post appears to be to berate a new user for not inherently *knowing* the answers.


What a helpful forum community. I suppose my solution should be to find a different platform.

A quick Google search shows that this error occurs in FreeBSD 9.0, and was claimed to be related to the ZERO_COPY_SOCKETS option in kernel configuration. Unfortunately that's as far as my FreeBSD knowledge will go. Is this function enabled in FreeNAS?

 

[jgreco]

So..

my question about upgrading a few months ago went unanswered because you don't like the question. Thankfully I was able to resolve the issue myself. And I see no reference to virtualization anywhere in the FAQ or wiki.. except in that FreeBSD can be virtualized and several of your links even refer to ZFS use in VirtualBox. And your own documentation on this site says only that ZFS can be used with less than 8Gb of RAM but performance may be reduced; not 4Gb of RAM is a "grave mistake". So my previous valid and simple technical question was ignored because you can't be bothered.. and now that I do appear to have an actual error, you have no solution, no recommendation, no troubleshooting path to follow to validate the issue; the only reason for your post appears to be to berate a new user for not inherently *knowing* the answers.

What a helpful forum community. I suppose my solution should be to find a different platform.

The people providing most of the help on this forum are generally not FreeNAS developers; the documentation you attribute to cyberjock was not written by him.

That said, the anecdotal evidence is that running ZFS on 4GB is possible but asking for trouble - if you want to do that, you may need to do some significant tuning (examples available on the forum). There is also significant anecdotal evidence that running FreeNAS in a VM is asking for trouble. While neither of these are hard limits (and I violate both with impunity), the fact remains that these are not good ideas for beginners. FreeNAS is fundamentally targeted at well-resourced systems running on bare metal.

cyberjock happens to have nearly 3,000 posts in this forum, many of which have been spent trying to assist people running FreeNAS on marginal configurations. I think the end result of this is clear in what he said: "We're so sick of trying to explain it."

 

[cyberjock]

And just so you don't think I have the answer but are choosing to let you suffer, I don't have the answer. When almost anything goes wrong in a VM all hell breaks loose and its near impossible to identify it via a forum setting, let alone consider if it is even fixable. Literally people have just started experimenting until either they gave up or they got it working. Sometimes it makes some sense later(Oh.. the FreeNAS install disk was bad) but sometimes its so nefarious nobody understands exactly what went wrong.

And no, its not about you not inherently knowing the answer. If you had read up on how ZFS works, you'd see words like "bare metal" and "do not use in a virtual environment".

Then, to make things worse, if you say "Only ESXi pros should ZFS in a virtual environment", suddenly 90% of people that have ever used ESXi, even used it just once for a few hours, thinks they are a "pro" and do it. Then can't explain why FreeNAS "lost" their data later.

I've spent many hours trying to help people, I've done Teamviewer sessions in remote places like South Africa, sometimes for hours(and always for free). The last time I did Teamviewer I spent 3 hours trying to help a user identify a "slow FreeNAS server" that was actually the fault of the Windows program that he uses to copy his data to the server, teracopy.

So feel free to tell me I'm not helpful. I told you what I'd do.. try a new USB stick. If that doesn't work I don't have any other options that I have ever seen work for anyone else. I Googled your error just to see what it meant last night, and I didn't see anything that would apply to FreeBSD 8, let alone FreeNAS. But I'm not helpful... so I'll leave now... My mommy is calling me for dinner :P