By Mike Dietrich-Oracle on Jan 14, 2016
A bit more than two months ago I did hear from several people having issues with our Hands-On Lab environment. And it became clear that only those who use Oracle Virtual Box 5 see such errors.
- VBox 5.0.10 crash issues with our Hands-On-Lab (Nov 30, 2015)
- Oracle VirtualBox 5.0.x - Segmentation Fault in PERL (Nov 12, 2015)
And interestingly one of my colleagues, our PL/SQL product manager Bryn Llewellyn started an email thread and a test internally yesterday as well. The issue seem to occur only on newer versions of Apple's MacBooks.
Potential Root Cause
The PERL issues seem to happen only on specific new Intel CPUs with a so called 4th level cache.
The current assumption is that Intel CPUs with Iris Pro graphics are affected. Iris Pro means eDRAM (embedded DRAM) which is reported as 4th level cache in CPUID. We have confirmed that Crystal Well and Broadwell CPUs with Iris Pro are affected. It is likely that the Xeon E3-1200 v4 family is also affected.
It seems to be that there's a bug in the perl binary. It links against ancient code from the Intel compiler suite doing optimizations according to the CPU features. Very recent Intel CPUs have 4 cache descriptors.
People who encountered this used Virtual Box VBox 5.0.x - and it passes this information to the guest. This leads to a problem within the perl code. You won't see it on VBox 4.3 as this version does not pass the information to the guest.
But actually it seems that this issue is independent of Virtual Box or any other virtualization software. It simply happens in this case as many people use VBox on Macs - and some Macs are equipped with this new CPU model. But people run Oracle in VBox environments and therefore see the issue as soon as they upgraded to VBox 5.0.x.
If you are using Oracle in VBox there are actually two solutions:
- Revert to VBox 4.3 as this won't get you in trouble
This problem was not triggered on VBox 4.3.x because this version did not pass the full CPUID cache line information to the guest.
- Run this sequence of commands in VBox 5.0 to tweak the CPUID bits passed to the guest:
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/Leaf" "0x4"
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/SubLeaf" "0x4"
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/eax" "0"
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/ebx" "0"
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/ecx" "0"
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/edx" "0"
VBoxManage setextradata VM_NAME "VBoxInternal/CPUM/HostCPUID/Cache/SubLeafMask" "0xffffffff"
- Of course you'll need to replace VM_NAME by the name of your VM.
If the error happens on a bare metal machine meaning it happens not inside a virtual image but on a native environment then the only chance you'll have (to my knowledge right now) is to exchange the PERL before doing really something such as running root.sh or rootupgrade.sh in your Grid Infrastructure installation or before using the DBCA or the catctl.pl tool to create or upgrade a database.
In this case please refer to the blog post of Laurent Leturgez:Issues with Oracle PERL causing segmentation faults:
This issues is currently tracked internally as bug 22539814: ERRORS INSTALLING GRID INFRASTRUCTURE 126.96.36.199 ON INTEL CPUS WITH 4 CACHE LEVEL.
So far we have not seen reports by people encountering this in a native environment but only by people using VBox 5.0.x or Parallels or VMware on a very modern version of Apple hardware.