Shlrm.org Blag » W00t!

New theme!

David Kowis — Sat, 03 Sep 2011 06:04:38 +0000

Yay there’s a new theme! It’s a bit nicer than the old one; less fancy graphics and a better layout.

Far more customizable also. I’m satisfied.

MINECRAFT Magnets!

David Kowis — Thu, 10 Mar 2011 16:26:11 +0000

I has dem!

I got some Minecraft magnets and they're on my storage cabinet at work.

Userspace cgroups in Fedora 14

David Kowis — Mon, 22 Nov 2010 00:08:35 +0000

There was a lot of buzz on the interblags about a 200-line kernel patch that enables per-tty cgroups automatically. Apparently, one can add them trivially to their home directory without having to patch any kernels.

This blog post talks about how to do it, but it didn’t cooperate with Fedora 14 very well. A bit of googleing later and I found this mailing list post that did it for me. Now I have userspace cgroups for each terminal I open. Handy, I suppose. Might be more useful on an SSH server to guarantee that each person logging in can’t overwhelm the system for the others.

Minecraft Server Modification Project

David Kowis — Thu, 14 Oct 2010 20:01:46 +0000

MINECRAFT!

Someone has done no small amount of determining what the code within the minecraft_server.jar does and how you can inject hooks into it. I have forked that git repository and am trying to organize it a bit better. Possibly make it truly into just a plugin framework and nothing else.

I’m hoping that this will be useful to others and that it all won’t horribly break when the server is changed on the 31st. Otherwise, all the really awesome administrative abilities will be horribly broken. Another really awesome thing would be if Notch were to have a plugin API ready to go. Perhaps based on the work that the community is doing.

vim syntax hilighting for ruby/rails

David Kowis — Wed, 19 May 2010 02:10:13 +0000

http://www.vim.org/scripts/script.php?script_id=1567

Woot.

EDIT:

Man, this guy has all sorts of good stuff: http://www.vim.org/account/profile.php?user_id=9012

cucumber, rails, ruby, git-vim integration. VIM FTW!

xen pv_ops domU

David Kowis — Sat, 01 May 2010 23:30:19 +0000

…means I can finally pause/suspend a domU vm again!

Finding this information should’ve been obvious, but for some reason it wasn’t. Maybe I had some silly mental block or something. Anyways, get the kernel source from here. Then build it for your architecture. If you want to build a 32-bit kernel for some 32-bit domUs, and you’re running on 64-bit, it’s as easy as make ARCH=i386 . This does work and I’ve verified it. Had to fool a Fedora domU into beleiving that it really was a 32-bit system.

I’ve found make tarbz2-pkg to be quite handy in packaging up the kernel to be deployed.

I have verified that this works in Xen 3.4.2 on a patched 2.6.29.6 kernel.

On my Xen 4.0 test box, it fails to suspend. I’m using the blktap2 stuff, and perhaps that doesn’t pause well. As far as I understand it, that blktap2 should not affect suspending, but I’m going to test it with some logical volume based vms. I usually use the lvm backed disks anyway, but the blktap2 stuff offers some interesting features, if it were to work. Not being able to pause stuff probably isn’t good, but again, I’m not sure what’s causing it.

Apparently, that is what’s causing it. The domU will pause and unpause just fine when using an lvm backed disk, rather than the blktap2 ones. I should test a couple of other combinations to see if things like tap:aio will behave, as that’s needed for nifty things like remus.

Xen 4.0 released

David Kowis — Wed, 07 Apr 2010 12:37:45 +0000

Finally!

From the official page:

The Xen 4.0 release contains a number of important new features and updates including:

Blktap2 – High performance VHD implementation supporting snaphots and clonces including live snapshots

Netchannel2 – Support for new Smart NICs with multi-queue and SR-IOV functionality

Fault Tolerance – Live transactional synchronization of VM state between physical servers

Libxenlight – New library providing higher-level control of Xen between various toolstacks

PV-USB and VGA Pass-through

SourceMage has already updated packages for it.

There’s a repository and src RPMs available for Fedora here. Specifically the Xen 4.0 src RPM. I’ll try to remember to fire up a build on my xen DomU that I use to build RPMs for me :)

Xen Stats Revised

David Kowis — Mon, 08 Mar 2010 12:38:57 +0000

I had reimplemented some monitoring on my network and then I got to wondering if there was a revised version of the original xen-stats stuff I was using. Turns out there is. The site details instructions on how to set it up in cacti, and it works pretty well. I do wish there was a single graph to collect all for the hosts, instead of individual host graphs, but it’s not bad. Perhaps I’ll build a template that uses the data source and glues them all into one graph. But it provides reasonably accurate data, and it’s not difficult to set up.

Xen stats FTW!

(The UPS graphs I need to fix too, somethings broken in the PHP datasource it uses. So if you’ve got a reliable Network UPS Tools graphing source for cacti, other than this one, lemme know.)

Xen 3.4.2 rpms for Fedora 11 x86_64

David Kowis — Thu, 12 Nov 2009 15:46:46 +0000

I was using xen 3.4.1 on my fedora 11 Domain0, but I couldn’t ever suspend anything. xm save always failed. Someone on IRC suggested that it was the guest kernel that was to blame. Turns out it was xen 3.4.1.

After many hours searching the intertubes for a srpm or a spec file for building xen 3.4.2 for fedora, I decided that I would hack an existing one to 3.4.2 and hope for the best.

It built after I removed a few patches. The patches mostly complained about being already applied, so I assume the bugs the patches were addressing were fixed in 3.4.2. I have generated rpms for x86_64 and put the spec file up on my site. Enjoy.

Migration proceeding

David Kowis — Tue, 01 Sep 2009 20:17:09 +0000

The new cpu coolers fit and I can highly recommend them. The loudest fan on the server is the 5-drive sata hot-swap bay. I’ll make a posting detailing the server and the pitfalls I encountered for others on the internet, if any others actually read this, heh.

Anyways, the migration is proceeding, I have 10VMs running on the xen host. I have a few more to build to get the rest of my services segregated enough. I’m using LDAP on a VM to have centralized authentication and authorization. It’s still evolving slowly, but I can get the services I need running on a vm as they were, and then build a new VM to start the LDAP integration. Xen rules.