Tuesday, April 15, 2014

Configuring autofs for GlusterFS 3.5

GlusterFS 3.5 has not been released yet, but that should happen hopefully anytime soon (currently in beta). The RPM-packaging in this version has changed a little, and now offers a glusterfs-cli package. This package mainly contains the gluster commandline interface (and pulls in any dependencies).

On of the very useful things that is now made possible, is to list the available volumes on Gluster Storge Servers. This similar functionality is used by the /etc/auto.net script to list NFS-exports that are available for mounting. The auto.net script is by default enabled after installing and starting autofs:

# yum install autofs
# systemctl enable autofs.service
# systemctl start autofs.service

Checking, and mounting NFS-exports is made as easy as:

$ ls /net/nfs-server.example.net
archive  media  mock_cache  olpc
$ ls /net/nfs-server.example.net/mock_cache/fedora-rawhide-armhfp/
yum_cache

Making this functionality available for Gluster Volumes is simple, just follow these steps:

  1. install the gluster command

     # yum install glusterfs-cli
  2. save the file below as /etc/auto.glfs

     #!/bin/bash
     # /etc/auto.glfs -- based on /etc/auto.net
     #
     # This file must be executable to work! chmod 755!
     #
     # Look at what a host is exporting to determine what we can mount.
     # This is very simple, but it appears to work surprisingly well
     #
    
     key="$1"
    
     # add "nosymlink" here if you want to suppress symlinking local filesystems
     # add "nonstrict" to make it OK for some filesystems to not mount
     opts="-fstype=glusterfs,nodev,nosuid"
    
     for P in /usr/local/bin /usr/local/sbin /usr/bin /usr/sbin /bin /sbin
     do
         if [ -x ${P}/gluster ]
         then
                 GLUSTER_CLI=${P}/gluster
                 break
         fi
     done
    
     [ -x ${GLUSTER_CLI} ] || exit 1
    
     ${GLUSTER_CLI} --remote-host="${key}" volume list | \
         awk -v key="$key" -v opts="$opts" -- '
         BEGIN   { ORS=""; first=1 }
                 { if (first) { print opts; first=0 }; print " \\\n\t/" $1, key ":/" $1 }
         END     { if (!first) print "\n"; else exit 1 }' | \
         sed 's/#/\\#/g'
  3. make the script executable

     # chmod 0755 /etc/auto.glfs
  4. add an automount point to the autofs configuration

     # echo /glfs /etc/auto.glfs > /etc/auto.master.d/glfs.autofs
  5. reload the autofs configuration

     # systemctl reload autofs.service

After this, autofs should have created a new /glfs directory. The directory itself is empty, but a ls /glfs/gluster.example.net will show all the available volumes on the gluster.example.net server. These volumes can now be accessed through the autofs mountpoint. When the volumes are not used anymore, autofs will automatically unmount them after a timeout.

Sunday, February 23, 2014

Setting up a test-environment for Apache CloudStack and Gluster

This is an example of how to configure an environment where you can test CloudStack and Gluster. It uses two machines on the same LAN, one acts as a KVM hypervisor and the other as storage and management server. Because the (virtual) networking in the hypervisor is a little more complex than the networking on the management server, the hypervisor will be setup with an OpenVPN connection so that the local LAN is not affected with 'foreign' network traffic.

I am not a CloudStack specialist, so this configuration may not be optimal for real world usage. It is the intention to be able to test CloudStack and its Gluster integration in existing networks. The CloudStack installation and configuration done is suitable for testing and development systems, for production environments it is highly recommended to follow the CloudStack documentation instead.

 .----------------.                       .-------------------.
 |                |                       |                   |
 | KVM Hypervisor | <------- LAN -------> | Management Server |
 |                |    ^-- OpenVPN --^    |                   |
 '----------------'                       '-------------------'
agent.cloudstack.tld                      storage.cloudstack.tld

Both systems have one network interface with a static IP-address. In the LAN, other IP-addresses can not be used. This makes it difficult to access virtual machines, but that does not matter too much for this testing.

Both systems need a basic installation:

  • Red Hat Enterprise Linux 6.5 (CentOS 6.5 should work too)
  • Fedora EPEL enabled (howto install epel-release)
  • enable ssh access
  • SELinux in permissive mode (or disabled)
  • firewall enabled, but not restricting anything
  • Java 1.7 from the standard java-1.7.0-openjdk packages (not Java 1.6)

On the hypervisor, an additional (internal only) bridge needs to be setup. This bridge will be used for providing IP-addresses to the virtual machines. Each virtual machine seems to need at least 3 IP-addresses. This is a default in CloudStack. This example uses virtual networks 192.168.N.0/24, where N is 0 to 4.

Configuration for the main cloudbr0 device:

#file: /etc/sysconfig/network-scripts/ifcfg-cloudbr0
DEVICE=cloudbr0
TYPE=Bridge
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.1
NETMASK=255.255.255.0
NM_CONTROLLED=no

And the additional IP-addresses on the cloudbr0 bridge (create 4 files, replace N by 1, 2, 3 and 4):

#file: /etc/sysconfig/network-scripts/ifcfg-cloudbr0:N
DEVICE=cloudbr0:N
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.N.1
NETMASK=255.255.255.0
NM_CONTROLLED=no

Enable the new cloudbr0 bridge with all its IP-addresses:

# ifup cloudbr0
Any of the VMs that have a 192.168.*.* address, should be able to get to the real LAN, and ultimately also the internet. Enabling NAT for the internal virtual networks is the easiest:
# iptables -t nat -A POSTROUTING -o eth0 -s 192.168.0.0/24 -j MASQUERADE
# iptables -t nat -A POSTROUTING -o eth0 -s 192.168.1.0/24 -j MASQUERADE
# iptables -t nat -A POSTROUTING -o eth0 -s 192.168.2.0/24 -j MASQUERADE
# iptables -t nat -A POSTROUTING -o eth0 -s 192.168.3.0/24 -j MASQUERADE
# iptables -t nat -A POSTROUTING -o eth0 -s 192.168.4.0/24 -j MASQUERADE
# service iptables save

The hypervisor will need to be setup to act as a gateway to the virtual machines on the cloudbr0 bridge. In order to so do, a very basic OpenVPN service does the trick:

# yum install openvpn
# openvpn --genkey --secret /etc/openvpn/static.key
# cat << EOF > /etc/openvpn/server.conf
dev tun
ifconfig 192.168.200.1 192.168.200.2
secret static.key
EOF
# chkconfig openvpn on
# service openvpn start

On the management server, it is needed to configure OpenVPN as a client, so that routing to the virtual networks is possible:

# yum install openvpn
# cat << EOF > /etc/openvpn/client.conf
remote real-hostname-of-hypervisor.example.net
dev tun
ifconfig 192.168.200.2 192.168.200.1
secret static.key
EOF
# scp real-hostname-of-hypervisor.example.net:/etc/openvpn/static.key /etc/openvpn
# chkconfig opennvpn on
# service openvpn start

In /etc/hosts (on both the hypervisor and management server) the internal hostnames for the environment should be added:

#file: /etc/hosts
192.168.200.1 agent.cloudstack.tld
192.168.200.2 storage.cloudstack.tld

The hypervisor will also function as a DNS-server for the virtual machines. The easiest is to use dnsmasq which uses /etc/hosts and /etc/resolv.conf for resolving:

# yum install dnsmasq
# chkconfig dnsmasq on
# service dnsmasq start

The management server is also used as a Gluster Storage Server. Therefor it needs to have some Gluster packages:

# wget -O /etc/yum.repo.d/glusterfs-epel.repo \
http://download.gluster.org/pub/gluster/glusterfs/3.4/LATEST/RHEL/glusterfs-epel.repo
# yum install glusterfs-server
# vim /etc/glusterfs/glusterd.vol

# service glusterd restart

Create two volumes where CloudStack will store disk images. Before starting the volumes, apply the required settings too. Note that the hostname that holds the bricks should be resolvable by the hypervisor and the Secondary Storage VMs. This example does not show how to create volumes for production usage, do not create volumes like this for anything else than testing and scratch data.

# mkdir -p /bricks/primary/data
# mkdir -p /bricks/secondary/data
# gluster volume create primary storage.cloudstack.tld:/bricks/primary/data
# gluster volume set primary storage.owner-uid 36
# gluster volume set primary storage.owner-gid 36
# gluster volume set primary server.allow-insecure on
# gluster volume set primary nfs.disable true
# gluster volume start primary
# gluster volume create secondary storage.cloudstack.tld:/bricks/secondary/data
# gluster volume set secondary storage.owner-uid 36
# gluster volume set secondary storage.owner-gid 36
# gluster volume start secondary

When the preparation is all done, it is time to install Apache CloudStack. It is planned to have support for Gluster in CloudStack 4.4. At the moment not all required changes are included in the CloudStack git repository. Therefor, is is needed to build the RPM packages from the Gluster Forge repository where the development is happening. On a system running RHEL-6.5, checkout the sources and build the packages (this needs a standard CloudStack development environment, including java-1.7.0-openjdk-devel, Apache Maven and others):

$ git clone git://forge.gluster.org/cloudstack-gluster/cloudstack.git
$ cd cloudstack
$ git checkout -t -b wip/master/gluster
$ cd packaging/centos63
$ ./package.sh

In the end, these packages should have been build:

  • cloudstack-management-4.4.0-SNAPSHOT.el6.x86_64.rpm
  • cloudstack-common-4.4.0-SNAPSHOT.el6.x86_64.rpm
  • cloudstack-agent-4.4.0-SNAPSHOT.el6.x86_64.rpm
  • cloudstack-usage-4.4.0-SNAPSHOT.el6.x86_64.rpm
  • cloudstack-cli-4.4.0-SNAPSHOT.el6.x86_64.rpm
  • cloudstack-awsapi-4.4.0-SNAPSHOT.el6.x86_64.rpm

On the management server, install the following packages:

# yum localinstall cloudstack-management-4.4.0-SNAPSHOT.el6.x86_64.rpm \
cloudstack-common-4.4.0-SNAPSHOT.el6.x86_64.rpm \
cloudstack-awsapi-4.4.0-SNAPSHOT.el6.x86_64.rpm

Install and configure the database:

# yum install mysql-server
# chkconfig mysqld on
# service mysqld start
# vim /etc/cloudstack/management/classpath.conf

# cloudstack-setup-databases cloud:secret --deploy-as=root:

Install the systemvm templates:

# mount -t nfs storage.cloudstack.tld:/secondary /mnt
# /usr/share/cloudstack-common/scripts/storage/secondary/cloud-install-sys-tmplt \
-m /mnt \
-h kvm \
-u http://jenkins.buildacloud.org/view/master/job/build-systemvm-master/lastSuccessfulBuild/artifact/tools/appliance/dist/systemvmtemplate-master-kvm.qcow2.bz2
# umount /mnt

The management server is now prepared, and the webui can get configured:

# cloudstack-setup-management

On the hypervisor, install the following additional packages:

# yum install qemu-kvm libvirt glusterfs-fuse
# yum localinstall cloudstack-common-4.4.0-SNAPSHOT.el6.x86_64.rpm \
cloudstack-agent-4.4.0-SNAPSHOT.el6.x86_64.rpm
# cloudstack-setup-agent

Make sure that in /etc/cloudstack/agent/agent.properties the right NICs are being used:

guest.network.device=cloudbr0
private.bridge.name=cloudbr0
private.network.device=cloudbr0
network.direct.device=cloudbr0
public.network.device=cloudbr0

Go to the CloudStack webinterface, this should be running on the management server: http://real-hostname-of-mgmt.example.net:8080/client The default username/password is: admin / password

It is easiest to skip the configuration wizard (not sure if that supports Gluster already). When the normal interface is shown, under 'Infrastructure' a new 'Zone' can get added. The Zone wizard will need the following input:

  • DNS 1: 192.168.0.1
  • Internal DNS 1: 192.168.0.1
  • Hypervisor: KVM

Under POD, use these options:

  • Reserved system gateway: 192.168.0.1
  • Reserved system netmask: 255.255.255.0
  • Start reserved system IP: 192.168.0.10
  • End reserved system IP: 192.168.0.250

Next the network config for the virtual machines:

  • Guest gateway: 192.168.1.1
  • Guest system netmask: 255.255.255.0
  • Guest start IP: 192.168.1.10
  • Guest end IP: 192.168.1.250

Primary storage:

  • Type: Gluster
  • Server: storage.cloudstack.tld
  • Volume: primary

Secondary Storage:

  • Type: nfs
  • Server: storage.cloudstack.tld
  • path: /secondary

Hypervisor agent:

  • hostname: agent.cloudstack.tld
  • username: root
  • password: password

If this all succeeded, the newly created Zone can get enabled. After a while, there should be two system VMs listed in the Infrastructure. It is possible to log in on these system VMs and check if all is working. To do so, log in over SSH on the hypervisor and connect to the VMs through libvirt:

# virsh list
 Id    Name                           State
----------------------------------------------------
 1     s-1-VM                         running
 2     v-2-VM                         running

# virsh console 1
Connected to domain s-1-VM
Escape character is ^]

Debian GNU/Linux 7 s-1-VM ttyS0

s-1-VM login: root
Password: password
...
root@s-1-VM:~# 

Log out from the shell, and press CTRL+] to disconnect from the console.

To verify that this VM indeed runs with the QEMU+libgfapi integration, check the log file that libvirt writes and confirm that there is a -drive with a glusterfs+tcp:// URL in /var/log/libvirt/qemu/s-1-VM.log:

... /usr/libexec/qemu-kvm -name s-1-VM ... -drive file=gluster+tcp://storage.cloudstack.tld:24007/primary/d691ac19-4ec1-47c1-b765-55f804b78bec,...

Wednesday, December 11, 2013

Gluster and (not) restarting brick processes upon updates

Gluster users have different opinions on when the Gluster daemons should be restarted. This seems to be a very common discussion for a lot daemons, and pops up on the Fedora Developers mailinglist regularly.

An explanation on how and when Gluster starts its daemons is probably in order. A storage server running Gluster always has at least one process running, the management daemon (glusterd). The management daemon is responsible for building the Trusted Pool (aka cluster) of the Friends (other storage servers) that it knows. The glusterd process also handles the actions from the commandline client or other storage servers' glusterd processes.

Before a storage server provides bricks for a volume, glusterd is the only process that is running. After a volume has been created and started, each brick will have its own glusterfsd process. glusterd starts these glusterfsd processes when the volume is started (gluster volume start VOLNAME) or when booting and the volume should be in a 'started' state.

In addition to starting the brick processes, glusterd is also responsible for starting the NFS-server and the self-heal-daemon (when these are not disabled). Both of these processes are a glusterfs client process and are started once per storage server.

Client processes for mounting Gluster Volumes through FUSE are not started by the glusterd management daemon. These processes are started upon mounting and are not known to the Gluster processes that provide the storage services.

When updates are installed, it is highly recommended to restart all the binaries that had their content (either the binaries themselves, or loaded libraries) changed. When no restart is performed, the old binaries are still running and existing bugs that the update intends to fix are not applied. This add to the confusion about which version is running, because rpm -q glusterfs will return the updated version, which is different from the most recent version that has been logged when the daemons started.

Luckily, systemd makes it pretty easy to restart all processes that glusterd started. But, unfortunately there are some valid (advanced/power-user) use-cases where restarting all the processes is not needed and can cause more problems than it would prevent. To accommodate these users on Fedora, we have split the management of the daemons over two systemd services:
  • glusterd.service for starting/stopping the glusterd process
  • glusterfsd.service for stopping the glusterfsd/brick processes
On most storage servers, both services should be activated. glusterfsd.service does nothing on start, but it will kill the glusterfsd processes when it gets stopped (or restarted). The glusterd.service starts and stops the glusterd management process (which in turn starts the needed glusterfsd processes).

Those users that can not allow automatic updates restart the glusterfsd processes, can disable the glusterfsd.service and no processes that provide the bricks for the volumes should be restarted:

# systemctl disable glusterfsd.service

As long as this service is active (check with systemctl status glusterfsd.service), an update will cause a restart of the brick processes. Stopping the service and restarting the glusterd.service is required once, or a reboot will suffice too.

In order to have the glusterfsd processes stopped on shutdown, the glusterfsd.service file can be copied with a name that is unknown to the GlusterFS package. If the RPMs do not know about the service, they will not try to restart it. The following set of commands should work for these users:

# systemctl disable glusterfsd.service
# cp /usr/lib/systemd/system/glusterfsd.service /etc/systemd/system/multi-user.target.wants/glusterfsd-shutdown-only.service
# systemctl daemon-reload
# systemctl start glusterfsd-shutdown-only.service

Any issues, questions, suggestions or notes can be passed to me on IRC (ndevos on Freenode in #gluster) or can be reported in a bug against the Fedora GlusterFS package.

Sunday, December 1, 2013

Using Gluster as Primary Storage in CoudStack

CloudStack could use a Gluster environment for different kind of storage types:
  1. Primary Storage: mount over the GlusterFS native client (FUSE)
    This post shows how it is working and refers to the patches that make this possible.
  2. Volumes for virtual machines: use the libgfapi integration in QEMU
    Next upcoming task, initial untested patch in the wip-branch.
  3. Secondary Storage: mount over the GlusterFS native client (FUSE)
The current work-in-progress repository on the Gluster Community Forge already has functional support for creating Primary Storage on existing Gluster environments:
  • Infrastructure -> Primary Storage -> Add Primary Storage
    Add Primary Storage
  • Infrastructure -> Zones -> Add Zone - [wizard]
    Add Primary Storage through the Zone Wizard
Via the Infrastructure -> Primary Storage menu, the details of the newly created storage can be displayed.
Primary Storage Details

After creating a virtual machine from the standard CentOS template, it can be verified that the Primary Storage Pool on the Gluster environment is functioning. On the hypervisor that runs the VM:

[root@agent ~]# mount | grep gluster
gluster.cloudstack.example.net:/primary on /mnt/dd697445-f67c-33bc-af52-386de3ff7245 type fuse.glusterfs (rw,default_permissions,allow_other,max_read=131072)

[root@agent ~]# ps -C qemu-kvm -o command | grep i-2-3-VM
/usr/libexec/qemu-kvm -name i-2-3-VM ... -drive file=/mnt/dd697445-f67c-33bc-af52-386de3ff7245/1afd48d2-c5e1-44ce-bcb3-051cc4d59716,if=none,id=drive-virtio-disk0,format=qcow2,cache=none ...

The changes to CloudStack that make this possible are located on the Gluster Community Forge and have been posted for review:
  • [#15932] Add support for Primary Storage on Gluster using the libvirt backend
  • [#15933] Add Gluster to the list of protocols in the Management Server

Monday, November 25, 2013

Initial work on Gluster integration with CloudStack

Last week there was a CloudStack Conference at the Beurs van Belage in Amsterdam. I attended the first day and joined the Hackathon. Without any prior knowledge of CloudStack, I was asked by some of the Gluster community people to have a look at adding support for Gluster in CloudStack. An interesting topic, and of course I'll happily have a go at it.
CloudStack seems quite a nice project. The conference showed an awesome part of the community, loads of workshops and a surprising number of companies that sponsor and contribute to CloudStack. Very impressive!
One of the attendants at the CloudStack Conference was Wido den Hollander. Wido has experience with integrating CEPH in CloudStack, and gave an explanation and some pointers on how storage is implemented.

Integration Notes

libvirt

It seems that the most useful way to integrate Gluster with CloudStack is to make sure libvirt know how to use a Gluster backend. Checking with some of my colleagues that are part of the group that support libvirt, quickly showed that libvirt knows about Gluster already (Add new net filesystem glusterfs).
This suggests that it should be possible to create a storage pool in libvirt that is hosted on a Gluster environment. A little trial and error shows that a command like this creates the pool:

# virsh pool-create-as --name primary_gluster --type netfs --source-host $(hostname) --source-path /primary --source-format glusterfs --target /mnt/libvirt/primary_gluster

The components that the above command uses, are:
  • primary_gluster: the name of the storage pool in libvirt
  • netfs: the type of the pool, netfs mounts the 'pool' under the given --target
  • $(hostname): one of the Gluster servers that is part of the Trusted Storage Pool that provides the Gluster volume
  • /primary: the name of the Gluster volume
  • /mnt/libvirt/primary_gluster: directory where libvirt will mount the Gluster volume
Creating a volume (a libvirt volume, which is a file on the Gluster volume) can be done through libvirt:

# virsh vol-create-as --pool primary_gluster --name virsh-created-vol.img --capacity 512M --format raw

This will create the file /mnt/libvirt/primary_gluster/virsh-created-vol.img and that file can be used as a storage backend for a virtual machine. An example of a snippet for the disk that can be attached to a VM:

    <disk type='network' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source protocol='gluster' name='/primary/virsh-created-vol.img'>
        <host name='HOSTNAME' port='24007'/>
      </source>
      <target dev='vda' bus='virtio'/>
    </disk>

There are some important prerequisites that need to be applied to the Gluster volume so that libvirt can start a virtual machine with the appropriate user. After setting these options on the Gluster volume and in /etc/glusterfs/glusterd.vol, a test virtual machine can get started. The log of the vm (/var/log/libvirt/qemu/just-a-vm.log) shows the QEMU command line, and this contains the path to the storage:

... /usr/libexec/qemu-kvm -name just-a-vm ... -drive file=gluster+tcp://HOSTNAME:24007/primary/virsh-created-vol.img,if=none,id=drive-virtio-disk0,format=raw,cache=none ...

Design Overview

When CloudStack utilized libvirt, it should be relatively straight forward to add support for Gluster in CloudStack. A diagram that shows the main interactions and their components looks like this:

                    .--------------.
                    |  CloudStack  |
                    '-------+------'
                            |
                      .-----+-----.
                      |  libvirt  |
                      '-----+-----'
                            |
           .----------------+--------------.
           |                               |
 .---------+----------.         .----------+----------.
 |  / storage pool /  |         |   virtual machine   |
 |  image management  |         |      management     |
 '---------+----------'         | / XML description / |
           |                    '----------+----------'
           V                               |
........................                   V
:     / vfs/fuse /     :     .............................
:  mount -t glusterfs  :     :    / QEMU + libgfapi /    :
:......................:     :  qemu file=gluster://...  :
                             :...........................:

The parts that are already functioning are these:
  • libvirt mounts a Gluster volume as a netfs/fuse-filesystem
  • create a XML definition for the disk and pass gluster:// on to QEMU

The actual development work will be in teaching CloudStack to intruct libvirt to use a Storage Pool backed by a Gluster Volume and attach disks to a virtual machine with the gluster protocol.

CloudStack Storage Subsystem modifications

Wido pointed out that most of the storage changes will be needed in the LibvirtStoragePoolDef and LibvirtStorageAdapter Java classes. Also the Storage Core would need to know about the new storage backend.
After some browsing and reading the sources, the needed modifications looked straight forward. The Gluster backend compares to the NFS backend, which can be used as an example.
Changing the code is an easy part, compared to testing it. Remember that I have no CloudStack background what so ever... Setting up a CloudStack environment to see if the modifications do anything, is far from trivial. Compared to the time I spend on changing the source code, trying to get a minimal test environment functioning took most of my time. At this moment, my patches are untested and therefore I have not posted them for review yet :-/

Setting up a CloudStack environment for testing

Some pointers to setup a development environment:
  • Building CloudStack manually (non RPMs)
  • maven 3.0.4 has been deprecated, use maven 3.0.5 instead
  • Installation Guide
  • RHEL6 requires the Optional Channel for jsvc from the jakarta-commons-daemon-jsvc package
  • install the cloudstack-agent (and -common) package
  • set guid and local.storage.uuid in /etc/cloudstack/agent/agent.properties

Running the CloudStack Management server is easy enough when the sources are checked out and build. A command like this works for me:

# mvn -pl :cloud-client-ui jetty:run

To deploy the changes for the cloudstack-agent, I prefer to build and install RPMs. Building these is made easy by the packaging/centos63/package.sh script:

# cd packaging/centos63 ; ./package.sh ; cd -

This script and the resulting packages work well on RHEL-6.5.

Upcoming work

With the test environment in place, I can now start to make changes to the Management Server. The current modifications in the JavaScript code make it possible to select Gluster as a primary storage pool. Unfortunately, I'm no web developer and changing JavaScript isn't something I'm very good at. I will be hacking on it every now and then, and hope to be able to have something suitable for review soon.
Of course, any assistance is welcome! I'm happy to share my work in progress if there is an interest. No guarantees about any working functionality though ;-)

Saturday, May 4, 2013

Fedora 18 Remix for Genesi EFIKA MX Smartbook available

After quite some delay, I have been able to try out a work-in-progress kernel-tree (3.7) from Sascha Hauer for the Genesi EFIKA MX Smartbook. The Fedora Remix image I have created uses the barebox bootloader to load the device-tree and the kernel (a zImage with concatenated initramfs).

The contents of the image is based on the Fedora 18 Generic Root Filesystem armhfp. XFCE and most of the desktop basics are included. Very little changes were needed over all. As the Smartbook has only 512MB of RAM, it is recommended to add some swap space, re-using the swap on the internal HD works for me (you need to update your /etc/fstab).

The current kernel configuration as found in Sascha's tree does not play very nice with the Fedora rootfs. When exercising some load, quite some oopses occur and it often results in a kernel panic (this happens because some 'sh' process reads /proc/meminfo, no idea what process, or why). I have been able to re-configure the kernel to the Fedora specifics, while keeping to the options from Sascha's defconfig. This kernel looks more stable, and a 'yum update' over the integrated Wifi adapter has finished successfully. So, if you have tried an earlier (not publicly announced) image, it would be in your benefit to update to this new release.

A difficulty with using this image, is that you need to configure your Smartbook to boot from SD-card, not the internal SPI-NOR. This change is done by flipping three dip-switches that are located under the keyboard, next to the flat-cable that connects the keyboard. The Genesi site contains a very good explanation on removing the keyboard so that you can access the switches.

The standard and default configuration of these switches cause the system to use the bootloader (uboot) to boot from the internal SPI-NOR and look like this:

 +---------+
 | X       |
 |   X X X |
 +---------+
Change this to the following to boot with barebox from the SD-card:
 +---------+
 |     X X |
 | X X     |
 +---------+

For now, I was only successful with booting from the left SD-card slot. barebox should also support booting from the micro-SD-card slot that is accessible by removing the battery. You will need to modify the barebox configuration (adding variables/scripts) for this. A future release of this remix will hopefully come with a modified barebox configuration so that both card slots work (and also separating zImage from the initramdisk).

These instructions and a link for downloading are captured in the Fedora Wiki and anyone is free to improve, correct and amend that page.

Sunday, April 7, 2013

Configuring a bluetooth keyboard system-wide from the command line

Recently I bought a new keyboard, which I intend to use when my laptop is placed in its docking station. There are two external monitors connected, making the display of the laptop rather useless (only two outputs are supported at the same time). In normal circumstances the laptop lid will be closed, so the keyboard is not accessible.

My new keyboard is a Logitech K760 and is connected through bluetooth. Pairing with help from the the XFCE/GNOME tools is easy enough, but this causes the keyboard to be available after login only. That is not very practical. After boot, I have to login through GDM and prefer to not need to use the keyboard of the laptop itself. For this, I needed to figure out how to make the bluetooth keyboard available on system level, and not per user. Descriptions on how to do this seem to be very sparse, and mostly depend on other distributions than RHEL or Fedora. I prefer to use standard tools as much as possible, adding custom scripts for these things makes it more difficult to move configurations between systems. Furthermore the keyboard can be paired to multiple (3) systems at the same time, the F1-3 keys can be used to select a system, similar to a KVM switch.

The most minimal and easy to use tools I could find, are included in the test suite of the BlueZ package. Unfortunately, these are not packaged for all I know, so installing or using these scripts is impractical. But, as these scripts are only needed for pairing once, I think they are a nice solution anyway. The advantage over other options, is that the scripts are updated with the bluez software itself, which causes the same scripts (well, different versions) to work regardless of changes to the bluez API.

Getting the scripts from the bluez test-suite that matches the available version in Fedora or RHEL, can be done with yumdownloader from the yum-utils package (all as normal unprivileged user):

$ yumdownloader --source bluez

Extract the source RPM by installing it:

$ rpm -ivh bluez-4.66-1.el6.src.rpm

Extract the sources which include the test-suite:

$ rpmbuild --nodeps -bp ~/rpmbuild/SPECS/bluez.spec
Note that the --nodeps parameter is used. The -bp argument causes all BuildRequires dependencies to be checked, most of them are not needed for the test-suite scripts.

After extracting the sources successfully, the test-suite is located under the BUILD directory:

$ cd ~/rpmbuild/BUILD/bluez-4.66/test/

Everything is now ready for pairing, so put the keyboard in discovery mode and scan for it:

$ sudo hcitool scan
Scanning ...
 00:1F:20:3C:A2:03 Logitech K760

The keyboard will need ao authenthicate to the system. simple-agent can be used for that, like this:

$ sudo ./simple-agent hci0 00:1F:20:3C:A2:03
DisplayPasskey (/org/bluez/2117/hci0/dev_00_1F_20_3C_A2_03, 716635)
Release
New device (/org/bluez/2117/hci0/dev_00_1F_20_3C_A2_03)
The simple-agent script will wait for a response of the keyboard, press the PIN that is shown (here 716635) and hit enter.

Obviously the keyboard is a device that supports the input-class. Hence test-input can be used to setup the connection:

$ sudo ./test-input connect 00:1F:20:3C:A2:03

If this worked without error message, mark the keyboard as a trusted device. This will make it possible for the keyboard to connect to the system without requesting for approval:

$ sudo ./test-device trusted 00:1F:20:3C:A2:03 yes

After these steps, verify that the keyboard connects automatically after a reboot. This worked for me on my RHEL-6 laptop, and a cubieboard installed with Fedora 18 ARM.