1. Memory deduplication on kvm machines: matching memory pages are COWed. Hopefully there is a re-spin of the virtio drivers too (which rock, btw).
2. Way newer kvm/libvirt (the old ones sucked)
3. Python 2.6. They skipped 2.5 entirely, which is nice.
Just keep in mind, they'll be supporting it for a VERY long time, so RHEL6 will be looking pretty tired in another 3.5 years (the current age of RHEL5).
I wonder, will I be able to use Xen on RHEL6 servers? Should I?
I'm learning to use virtualization and I picked Xen because seemed to me like solid technology - it's good for Amazon, Google and prgmr.com, so surely it will be good enough for me? On the other hand, it is not included in the kernel, its usage tends to lead to using anscient kernels, Red Hat and Ubuntu are moving away from it. I'm in doubt what virtualization technology should I be using.
Yes. In fact KSM can be used on any Linux process although you have to mark the regions that can be merged with a special mmap flag. It works well with VMs because they basically mmap a huge chunk of sequential memory (for the VM's RAM) which is marked thus.
You can always make the argument that you could delay the release of the distro to get "the next version of critical library/tool X", however, then you never release.
That means I'm looking forward to CentOS 6 soon. I hope.
QEMU/KVM virtualization is very nice and hopefully I won't need to rely on bleeding edge (though surprisingly stable) Fedora 13+ for a good stock deployment from now on.
Does anyone know if they removed all the X11 dependency garbage for a server install? An RHEL5 was approaching the bloat of a Solaris install. There was no "click here to install a slim server" option.
From some investigation, I think the simple answer is "yes", as long as you leave out devel, java, and a few specific tools. And totally yes for all the Xserver stuff.
I've got a kickstarted system with "@additional-server-devel
@base, @compat-libraries, @core, @development, @network-tools, @performance, @server-platform-devel, @system-admin-tools" package groups and a few specific package tweaks. Fits in under 2GB. Looks like there's no X server stuff, but there's libX11, a few other libX* packages, and gtk2 installed... It's being pulled in by some of the java stuff, seekwatcher, latencytop, python-matplotlib and a couple other devel things I probably don't care about. There's only 29 packages it wants to remove if I tell yum to remove libX11-common.
Looks to me like with a few more tweaks to my kickstart I'll be able to get all the X11 deps out.
Only having Perl 5.10 is a problem, and it comes down to timing. 5.12 was released upstream in April, didn't get into Fedora until mid-June, by which point it had missed the deadline for entering RHEL 6 (because of the extensive QA that we would require).
If you're a customer and you need 5.12, be sure to open a support ticket and/or talk to your TAM.
1. Memory deduplication on kvm machines: matching memory pages are COWed. Hopefully there is a re-spin of the virtio drivers too (which rock, btw).
2. Way newer kvm/libvirt (the old ones sucked)
3. Python 2.6. They skipped 2.5 entirely, which is nice.
Just keep in mind, they'll be supporting it for a VERY long time, so RHEL6 will be looking pretty tired in another 3.5 years (the current age of RHEL5).