Fatal trap 12 While reading data

[Dash_Ripone]

Hey all,

I am a noob troubleshooting a new truenas server.

I am trying to troubleshoot this fatal trap 12 error. It only is happening when transferring a file larger than ~1.8 GB FROM the server.
I have loaded over 500 GB of data to the server without issue.

Any help would be greatly appreciated! :)

 

[Samuel Tai]

What are the exact models of your WD Reds? If WD30EFAX, they're SMR disks, which are unsuitable for your pool, and could easily result in this error 12.

 

[Dash_Ripone]

What are the exact models of your WD Reds? If WD30EFAX, they're SMR disks, which are unsuitable for your pool, and could easily result in this error 12.

They are the WD30EFZX​

 

[Samuel Tai]

The culprit is likely your PCE-G2S4. See https://www.truenas.com/community/r...t-multipliers-and-cheap-sata-controllers.177/. This is an ASMedia-based SATA controller, but is only PCI-E 1x. As explained here: https://www.truenas.com/community/threads/sata-ports-extension-availability.95972/post-664171, the controller doesn't have enough PCI-E bandwidth to keep up with 4x drives, only 2x, and the error 12 is due to the controller dropping blocks in flight to try to keep up. This is very bad news for ZFS, which assumes the controller doesn't molest blocks in flight.

 

[Dash_Ripone]

The culprit is likely your PCE-G2S4. See https://www.truenas.com/community/r...t-multipliers-and-cheap-sata-controllers.177/. This is an ASMedia-based SATA controller, but is only PCI-E 1x. As explained here: https://www.truenas.com/community/threads/sata-ports-extension-availability.95972/post-664171, the controller doesn't have enough PCI-E bandwidth to keep up with 4x drives, only 2x, and the error 12 is due to the controller dropping blocks in flight to try to keep up. This is very bad news for ZFS, which assumes the controller doesn't molest blocks in flight.

Helpful Information.

After some research into BSD error messages I figured out that the issue was a bad RAM module. I swapped it for a known good one and all issues have cleared up. Thanks for all your assistance! :)