Red Hat Enterprise Linux 6 now available | Hacker News Reader

Red Hat Enterprise Linux 6 now available

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41 pointsUncle_Sam27 comments

This is fantastic news for virtualization:

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).

is memory deduplication the KSM thingy released about a year ago?

http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.3...

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.

Edit: madvise, not mmap.

Yes.

libguestfs ... a proper way to access and edit disk images.

(I am the author)

Thanks for creating and putting so many hours into this library. I think this tool more than any other has allowed me to do so much with KVM.

It's too bad they didn't skip to Python 2.7 which seems that will be the last 2.x version [1].

[1] http://sayspy.blogspot.com/2010/10/viewing-python-32-as-succ...

I don't think 2.7 has been out nearly long enough for a Linux distro to be based on it. RHEL uses Python for core stuff like yum.

Fedora 14 uses it and they could have delayed the release.

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.

The most important feature is _SHIPPING_.

They already delayed the release by 2 years more than they should've.

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.

The pv_ops patches are just starting to make it into mainline now, KVM's had quite a head start.

Xen is dead. KVM is now equally "solid", easier to use, better supported, etc.

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.

CentOS people are saying 4-6 weeks.

Nice, something to do over Christmas as I am teetotal this year.

They are already at it: https://twitter.com/#!/CentOS/status/2673891377946624

This truly is a milestone release for Red Hat that is putting a stake in the industry as the foundation for the next decade.

Am I the only one that took a double-take at that sentence?

I was fond of: This is a milestone event for Red Hat as we once again push forward and upward our leadership position in the market.

The message seems to have manifested from the collective will of all redhat employees. There's no human signer or sender.

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.

PostgreSQL 9.0 would have been nice, but I guess that's understandable.

Otherwise, a great release. RHEL is awesome. :)

I hope the standard version of Python is upgraded beyond 2.4.X.

Python 2.6. Also PHP 5.3 and MySQL 5.1.

But only Perl 5.10.1, they didn't upgrade to 5.12.* for some reason.

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.

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