The Rev. does it again.

Posted on March 30th, 2005 in little bit of politics by pete

Mykeru.com

I started reading mykeru.com a few months back after seeing an excerpt on someone else’s blog. He’s excellent. Well worth a regular read - here’s an example of the kind of high quality work he does.

http://haloscan.com/tb/mykeru/gunners_dream

The work he does is funny, angry, excellent and consistent. For what it’s worth, I’m adding him to my blogroll in the hope that it gives him some of that sweet, sweet googlejuice. He deserves it.

Mykeru.com

Deploying Novell’s Linux Server in a Windows Domain Environment

Posted on March 29th, 2005 in Work by pete

This is a good read - integrating SLES9 into a domain environment. I like the performance figures on the high end servers “the performance difference dropped to SLES9 only being about 25% faster than Win2k3 on higher end server hardware”

We’re starting to see a lot of interest in companies replacing older Windows servers with Linux. I heard through a contact that Microsoft commisioned an internal report recently to gauge the amount of interest in Linux from around 100 Middle Eastern companies. While around 15% said they were using Linux today (big sigh of relief in Redmond), 92% said they would use Linux in the next year (sharp intake of breath).

Flexbeta - Fighting the FUD - Deploying Novell’s Linux Server in a Windows Domain Environment - Page 1 - Introduction

Network interface bonding on SLES 9

Posted on March 4th, 2005 in Work by pete

A boring work related post this, but I need to keep it somewhere for a while and here is as good as any!

The first thing to do is to discover whether the network card supports miimon, ethtool monitoring or will you have to use arp-monitoring. This will determine the bonding module options that go into the /etc/modprobe.conf.local file. In VMWare using a vlance network card (which shows up in yast as an AMD PCNet - Fast 79C971 card), you can use miimon mode. To determine what capabilities the card in your test machine has, try running ‘ethtool eth0′ at the bash prompt. If you see something like

Settings for eth0
	Current message level: 0x00000007 (7)
	Link Detected: yes

then you can use miimon mode.

Configure the network card in yast, giving the first card the IP address that you want the bonded interface to have. Give the other network card(s) dummy IP addresses for now - we won’t be using the configuration so it doesn’t matter.

Next, go to a bash prompt and cd to /etc/sysconfig/network. In here there are various scripts and configuration files that control the network settings. The first step is to copy the ifcfg-id… file that you configured with an IP address to. The destination should be ifcfg-bond0 for the first bonded pair. Now that we have a template to start with, we need to discover the PCI bus IDs for the two ‘real’ NICs. At the prompt, type

grep bus-pci ifcfg-eth-id*

You should see somthing like this…

_nm_name='bus-pci-0000:00:11.0'
_nm_name='bus-pci-0000:00:12.0'

which are the addresses of the two physical cards. Using this information, we can now modify our ifcfg-bond0 file to tell it the card details to use. Add in a section like this at the end of the ifcfg-bond0 file.

BONDING_MASTER=yes
BONDING_SLAVE_0='bus-pci-0000:00:11.0'
BONDING_SLAVE_1='bus-pci-0000:00:12.0'

and save the file. The next step is to specify to the system which driver to load when bond0 if referenced. To do this, open the file /etc/modprobe.conf.local (NOT /etc/modprobe.config, that doesn’t survive a system upgrade) and add the lines

alias bond0 bonding
options bonding miimon=100 mode=0 use_carrier=0

This specifies that when we see bond0 being referenced, we need to load the bonding driver with the parameters outlined. The ‘miimon=100′ value tells the driver to use mii monitoring, watching every 100 milliseconds for a link failure. The ‘mode’ parameter specifies one of four bonding policies. The default is round-robin. Possible values are:

0 Round-robin policy: Transmit in a sequential order from the first available slave through the last. This mode provides load balancing and fault tolerance.

1 Active-backup policy: Only one slave in the bond is active. A different slave becomes active if, and only if, the active slave fails. The bond’s MAC address is externally visible on only one port (network adapter) to avoid confusing the switch. This mode provides fault tolerance.

2 XOR policy: Transmit based on [(source MAC address XOR'd with destination MAC address) modula slave count]. This selects the same slave for each destination MAC address. This mode provides load balancing and fault tolerance.

3 Broadcast policy: transmits everything on all slave interfaces. This mode provides fault tolerance.

If you are testing on VMware, you’ll find that the only working option is to use mode 1, since the emulated switch in VMware Workstation doesn’t seem to support anything else. In theory, it’s possbile to put the parameters in the ifcfg-bond0 file as a new line called BOND_MODULE_OPTS=’yadayada’ but with SLES 9 SP1 this doesn’t appear to work.

Now that we’ve built the configuration, we need to clear out the old ifcfg files that we don’t need. Just rm the ifcfg-eth-id* files in the /etc/sysconfig/network directory (after taking a backup!) and bounce the network.

rcnetwork restart

If all is well, you will see the bond0 interface appearing with the correct IP address and ‘as bonding master’, followed by two ‘enslaving eth’ lines. Verify the configuration using ifconfig and you’ll notice the MAC addresses for all the cards are identical, just as the IP addresses for eth0, eth1 and bond0 are identical.

If needed, you can repeat the process for a second bond, just modify the modprobe.conf.local with an ‘alias bond1 bonding’ line and carry on as before.

Update 9/3/2006:

Per kindly points out the default route requirements in the comments..

/etc/sysconfig/network/routes
adding:
default xx.xx.xx.x

adding that will aid in getting the bonded networkinterface to route outside the subnet.

Thanks Per!

I was hoping for a quiet summer, but

Posted on March 1st, 2005 in little bit of politics by pete

This - U.S to bomb Iran this June. - is very scary. I hope it turns out to be crap, but if it goes ahead, I really hope the UK has no part in it. Whatever you made of the ‘45 minutes from death‘ shit that Straw and others produced in the last justification for their war of choice (excuse the popup, you should be running firefox!), I don’t think even Blair’s toerag advisors could come up with something to justify that kind of action. Maybe he’s feeling bold, maybe he thinks he’s invincible. Maybe he knows there’s no alternative. Maybe Tim’s latest project could change things a wee bit.

Anyway, June is Luke’s birthday, so I’ll be busy doing something. Probably involving trains, engines, track, switches and locomotives. York, here we come….!