SOLVED Hard reboots when accessing iSCSI target

[Jon_Boy]

I have installed FreeNAS 9.2.1.4.1 on a HP ProLiant MicroServer N54L fitted with 16GB of ECC RAM. The system has 4 x 600GB Velociraptor HDs and boots from a Kingston 16GB USB device. It also has a dual port Intel gigabit NIC.

The onboard NIC is used for management (static IP).

The additional NICs are configured to be used for iSCSI and have MTU set to 9000.

The installation seems fine in that I am able to configure using the web interface, etc.

I created a zpool of two mirrored pairs and then created a zvol on this zpool. I then created a basic iSCSI configuration (with no authentication) and connected from a Windows 2008 R2 server and confirmed that I was able to read and write to the device.

I then disconnected this target in Windows and connected in vmware ESXi 5.1. I was able to format the volume and create a VM on this LUN. The VM is configured with a 100GB drive (thick lazy zeroed). On installing Ubuntu 14.04 the disk is formatted and data transfer begins (apparently quick). The FreeNAS system then hard reboots in the course of the disk activity. This is repeatable i.e. after the system restarts, all is fine until starting the VM install when it hard reboots again.

I have changed the USB boot device. I have reinstalled.

The system has worked reliably using Ubuntu installs including ZFS on Linux and IET which means that I am reasonably confident the hardware is OK.

I would like to switch to using FreeNAS for this system so advice on how to troubleshoot from here would be very much appreciated.

 

[cyberjock]

The first thing I'd try is getting rid of jumbo frames. Those are known to be a "problem child" for many people. Lots of NICs don't support jumbo frames in FreeBSD and causes all sorts of mischief.

 

[Jon_Boy]

That does indeed seem to have solved the problem. Is there any documentation around this that you are aware of? I've generally seen pretty worthwhile performance gains from jumbo frames (although this system is only for a home lab so not critical).

Thanks for the quick assistance!

 

[cyberjock]

Not really. The problem is that too many people don't have hardware that properly supports Jumbo Frames in FreeBSD. Normally Intel NICs support it just fine. But if your switches and network cards on the other machine don't work well you can have a real mess on your hands. For the vast majority of situations jumbo frames won't appreciably affect performance, so enabling it is only inviting problems. Even I am dealing with my own Jumbo Frames problem on a direct 10Gb link between my desktop and server. ;)

 

[Jon_Boy]

It seems I spoke too soon. The system has behaved much better with default mtu setting. I installed one Linux VM without problem and everything was nice and quick. I then installed another VM with Win2k8r2 which was fine. I then ran Windows update and around half way through installing the 150 or so updates FreeNAS hard rebooted. I then started again from scratch. Same problem at nearly the same point. Any more ideas or pointers gratefully received as otherwise I'm going to have to head back to Linux and the command line which seems a bit of a shame.

 

[Nick2253]

Did you do a memory check on your FreeNAS machine? I've seen a problem like this due to faulty memory, so run Memtest86+ just to be sure it isn't.

If your memory is good, try connecting to FreeNAS via that Windows Server. And then try transferring a bunch of data to FreeNAS via iSCSI. If that doesn't cause problems, that rules out some of the possible issues, and will give us a much better place to start.

If iSCSI transfer still causes problems, try connecting via SMB or NFS. Do you get problems with lots of data transfer then?

 

[Jon_Boy]

Thanks for the suggestions. I have opted to install Ubuntu server + ZFS for Linux + IET again + jumbo frames. Rock solid.

I'll save looking into FreeNAS for another time... Certainly impressed by the community.