Comment 6 for bug 162147

Rick,

Does your PowerEdge server have a PERC controller?

I'm getting this on Ubuntu 8.04 on a Dell 2950 that has the PERC 5/i controller.

This bug is happening now that I have taken the megaraid scsi driver code from RHEL 5 and modified it to compile in Ubuntu 8.04. With the Ubuntu driver the Xen dom0 would just panic whenever I tried to write a lot to the disk. Where "a lot" was dd'ing 100MB from /dev/zero followed by a call to sync.

Trying to get the full stack trace requires a serial console, which for the life of me I can't seem to figure out how to attach to Xen's dom0.

If you're having the problem and you're using the megaraid_sas scsi controller, maybe you'll be able to test out the driver code I'm modifying. assuming I can get it to be stable on my system. At the moment, the box isn't falling over, but I'm getting gobs of these messages:

May 12 18:56:20 phaethon kernel: [ 222.605912] sd 0:2:0:0: [sda] Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK,SUGGEST_OK
May 12 18:56:20 phaethon kernel: [ 222.605917] end_request: I/O error, dev sda, sector 93696298
May 12 18:56:20 phaethon kernel: [ 222.618742] sd 0:2:0:0: [sda] Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK,SUGGEST_OK
May 12 18:56:20 phaethon kernel: [ 222.618747] end_request: I/O error, dev sda, sector 93708338
May 12 18:56:20 phaethon kernel: [ 222.619380] sd 0:2:0:0: [sda] Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK,SUGGEST_OK
May 12 18:56:20 phaethon kernel: [ 222.619384] end_request: I/O error, dev sda, sector 93708858

As well as the PCI-DMA: Out of SW-IOMMU space errors on the console.

Scott