On 02/22/2013 03:04 PM, Reindl Harald wrote: > > Am 22.02.2013 20:58, schrieb Robert Moskowitz: >> Kernel param. I really should have caught that. >> >> So I was all ready to edit grub.conf and then slapped my hand. >> You TEST it out first, adding the command at boot time. ARGH! > one option > >> Once before (5+ years back) I had to add a kernel param and did it wrong and >> it was a big recovery challenge > what is the challenge? > there is no difference add or remove a param at boot
If you get the option wrong and the system will now not boot? Then you have to boot from a recovery CD, mount your harddrve /boot and edit out the change from grub.conf and try again. All the time you SHOULD have been working on something else. > >> But as I read up on this option, it does not sound like something I want >> to globally turn off just to stop a supposedly annoying >> message (if they have indeed worked around it, and my new DNS server is >> running with this OK) > and you looked at the other options? > "intel_iommu=igfx_off" maybe a good idea > > intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option > on > Enable intel iommu driver. > off > Disable intel iommu driver. > igfx_off [Default Off] > By default, gfx is mapped as normal device. If a gfx > device has a dedicated DMAR unit, the DMAR unit is > bypassed by not enabling DMAR with this option. In > this case, gfx device will use physical address for > DMA. > forcedac [x86_64] > With this option iommu will not optimize to look > for io virtual address below 32 bit forcing dual > address cycle on pci bus for cards supporting greater > than 32 bit addressing. The default is to look > for translation below 32 bit and if not available > then look in the higher range. > strict [Default Off] > With this option on every unmap_single operation will > result in a hardware IOTLB flush operation as opposed > to batching them for performance. > sp_off [Default Off] > By default, super page will be supported if Intel IOMMU > has the capability. With this option, super page will > not be supported. > I will look at these closely and figure out what course to test. The sabbath is almost here, so got a hard stop time. _______________________________________________ CentOS mailing list [email protected] http://lists.centos.org/mailman/listinfo/centos
