Author: Wido den Hollander

USB boot issues on a Soekris net6501-70

After 5 years of great service it was time to replace my Soekris net5501-70 by a new net6501-70.

I tried to install Ubuntu 14.04 via USB, but the Soekris wouldn’t boot from my Kingston Datatraveler USB stick.

It seems the Soekris is rather picky on the USB stick. This is what you don’t want to see:

comBIOS ver. 1.41c  20121115  Copyright (C) 2000-2011 Soekris Engineering.

net6501

2048 Mbyte Memory                        CPU Atom E6xx 1600 Mhz 


SATA AHCI BIOS ver. 0.61 20121115  Copyright (C) 2003-2011 Intel Corporation

Controller Bus#02, Device#06, Function#00: 02 Ports, 02 Devices
  Port-00: Hard Disk, INTEL SSDMCEAC060B3            
  Port-01: Hard Disk, WDC WD10JPVX-80JC3T0           

Soekris USB Expansion ROM ver. 1.01  20111203

82: USB 01                          Xlt -2-32   Mbyte

At 82 you see the USB stick isn’t properly discovered. This is what it should look like:

Soekris USB Expansion ROM ver. 1.01  20111203

82: USB 01  General UDisk           Xlt 994-255-63  7988 Mbyte

That shows t he USB stick is detected properly and you can now install Ubuntu! Simply dd a ISO to the USB stick.

Limit battery state of charge on a Lenovo X1 Carbon under Ubuntu

Since the end of 2012 I have a Lenovo X1 Carbon laptop running with Ubuntu 12.04

By default a laptop charges all the way up to 100% State of Charge, something which is very bad for a battery. There is a great video on Youtube about this if you want to know all the ins and outs.

The bottom line is that I wanted to limit the charge level to 90% for my laptop. Up until now I did this manually by pulling the plug at certain points, but that didn’t always work. I sometimes forgot and the battery would charge up to 100%.

On Github I found the tpacpi-bat project which allows you to limit the charge level of your battery.

How to install?

  • Clone the project
  • Run install.pl
  • Modify your /etc/rc.local file
  • Reboot

This is what you need to put in your rc.local:

tpacpi-bat -g SP 0
tpacpi-bat -g SP 1
tpacpi-bat -g SP 2

exit 0

As far as I know the X1 Carbon has 3 batteries, so for all three we set the charge limit to 90%. This is not persistent after reboots, so we have to set it every time we boot.

You’ll now see that your battery charges to 90% at max.

Deploying Ceph over IPv6

I like to deploy Ceph clusters over IPv6. I actually think that’s the way forward. IPv4 is legacy just like iSCSI and NFS are.

Last week I was at a customer deploying a new Ceph cluster and they wanted to deploy with IPv6! Most deployment I did with IPv6 were done manually and not with ceph-deploy, but when trying to deploy with ceph-deploy over IPv6 I ran into some issues.

Before going into that I want to make something clear. With Ceph you choose either IPv4 OR IPv6. There is NO dual-stack support. So the whole cluster (including clients) communicates over IPv6 or over IPv4. Switching afterwards is not possible. So that’s why I urge people to deploy with IPv6 since you probably want to have your cluster running for a long time.

All package repos (including the Ceph ones) have IPv6 enabled, so in my opinion there is no good reason to prefer IPv4 with a Ceph deployment when IPv6 is available. I even think it’s easier in large deployment due to the Router Advertisements in IPv6.

Having that said it’s time to go back to the ceph-deploy issue.

In ceph.conf you have to enclose IPv6 addresses for monitors with a [ and ]. This is what ceph-deploy did wrong:

[global]
mon_host = 2a00:f10:X:X::X,2a00:f10:X:X::Y,2a00:f10:X:X::Z

While it should have been:

[global]
mon_host = [2a00:f10:X:X::X],[2a00:f10:X:X::Y],[2a00:f10:X:X::Z]
ms_bind_ipv6 = true

The ms_bind_ipv6 setting tells the Messenger inside Ceph to bind on IPv6. It’s important that you set that setting on all hosts in the Ceph cluster, otherwise things will go wrong badly. Heartbeats and such will not work.

I wrote a patch for ceph-deploy which fixes it. It writes the ‘mon_host’ setting correctly and also adds the ‘ms_bind_ipv6’ setting when IPv6 is used for the monitors.