Updating Cobbler on RHEL5 to Import ESXi5 for PXE Install

So you want to play with ESXi5, but on RHEL5, today, the latest version of cobbler (2.2.1?) doesn't yet support it.  Cobbler 2.2.3 does, though, but it's not available at all yet.  Nooooooo.

Here's what you do:

1. install an RPMbuild of cobbler 2.2.3 .  Normally this is laughable-stupid, but we know the official one's coming eventually and we'll get the update from the official channels automatically.
   1. From the cobbler release_22 branch, go get the TGZ file for the latest 2.2 release:
      https://github.com/cobbler/cobbler/tarball/release22
   2. unpack that
      tar -C /tmp -xf cobbler-cobbler-cobbler-2.2.3-2-0-g80d646a.tar.gz(or just do it all in one go:
        wget -qO-  https://github.com/cobbler/cobbler/tarball/release22 | tar -C /tmp -xzf - )
   3. change and build it
      make -C /tmp/cobbler-cobbler-80d646a  rpms
   4. if you're me, you'll then remake it just to get the right apt repo, but hey.  People like to make things inside-out, and forget that the packaging is on the outside of the build.  Be nice to them, though, as they may be amateurs, and it's easy like rolling a stop-sign.
   5. install cobbler over what you have:
      rpm -Uvh  /tmp/cobbler-cobbler-80d646a/rpm-build/cobbler-2.2.3-2.noarch.rpm
   6. watch it fail when you do a cobbler check due to a missing and unreported dependency:
      cobbler check
   7. install said dependency, re-run cobbler check, think disapproving thoughts of the packagers:
      yum -y install python-ctypes
      cobbler check
2. grab your ESXi5 ISO
3. import that
   mount -o loop VMware-VMvisor-Installer-5.0.0.update01-623860.x86_64.iso /mnt/cdrom
   cobbler import -name esxi5 --path /mnt/cdrom/
4. rejoice
   more beer

It really is that easy, once you have a cheat-sheet.  Now go hack up a decent esxi5 KS and start installing like a boss.

(Discovered) Best Practice Config for OpenFiler iSCSI Storage for ESXi4

Update: OpenFiler performance and reliability remained low. I've since moved to another platform, and no, this isn't an ad so I'm not saying where I ended up.

That title sucks, but I'm hoping Google will like it.

The OpenFiler iSCSI box at the Eastern site bailed, due largely to congestion on the still-not-redundant switch we have in place (new stuff still in shipping, argh) and after the fallout I found some config tips for the OF 2.3 server.  This thing's a physical box with nothing but iSCSI on it, so it may be different if you're simulating some ESXi-ESXi virtual worlds in your mini-lab at work.

1. Disable Delayed ACK in the iSCSI storage adapter advanced properties on the ESXi host.  (scroll down)(via)
2. Reduce the VMs-per-LUN count to reduce the reservation count and conflict  Smaller LUNs, kids, despite what you hear.(via)
3. Change the default iSCSI timeout on your ESX server to 14 seconds: esxcfg-advcfg -s 14000 /VMFS3/HBTokenTimeout (via, via, via)
4. Keep your snapshots down:  they increase load, with the obvious impact.(via)
5. Consider upgrading your intel e1000 or exgb NICs, code here, intel instructions here, openFiler-derived procedure here.
6. Don't use more than one NIC (bonding) or more than one interface (different subnets) at a time with Openfiler. (via, via, instructions for OF)
7. Target tuning (via):
   1. DefaultTime2Wait should be changed to "10"
   2. ImmediateData should be changed to "Yes"
   3. MaxRecvDataSegmentLength should be changed to "262144"
   4. MaxXmitDataSegmentLength should be changed to "262144"
8. LUN tuning
   1. R/W mode should be changed to "write-back"
      (it should go without saying that a BBU is essential for your RAID controller)
   2. Transfer mode should be changed to "fileio"
      (this is controversial)
9. NEVER, EVER share LUNs between ESX hosts using Openfiler and IET.
   (Not sure how doable this one is in an ESXi cluster, but that's the suggestion.) (via)

So in my case, we're looking to implement a few of those.  Hopefully we'll not see this kind of issue any time soon, but watch this space in case we do see something after the upgrade/tuning.

The good news is that OF is considering another iSCSI target, and the changes are supposed to be very beneficial for performance and for us.

Kickstarting ESX VMs and Physical Hosts -- Knowing Which is Which

UPDATE: This method also does not work. Sorry.

Cobbler and kickstarting is my new cool toy.  I tinker with it FAR too much. I had a problem, though, that I need to install the vmware tools only on the VMs, and install smartmontools only on the physical hosts.  What's a guy to do?

After some digging, coding, hacking, testing, cursing, I finally discovered a decent switch I can use to identify a box by its mac.

Then I lost that code.

So I found another method.  This one's ugly as sin, but it may actually work.  Check this nasty-ass kung-fu:

#if ":".join($interfaces.eth0.mac_address.split(':')[0:3]) in "00:50:56 00:0C:29"

[code]

#end if

Yeah.  That's one ugly baby.  If Blogspot again truncates that line all to hell, remember the #if statement is all on the first line of 3.

Now to see how well it works.