Fun and games with OS X Lion Server

With the recent release of Lion I decided to upgrade my desktop from Snow Leopard client to Lion Server and at the same time migrate the Snow Leopard mac mini server over to it.

According to the combination of a knowledge base article and the migration instructions Chapter 3 page 24 this should be easy. It was not.

The knowledge base instructions say in step 2-7

Open “Install Mac OS X Lion”. Note: In order to install Lion Server, the Server app must be in the same folder as the Install Mac OS X app. If you just purchased Lion Server, these items should be in the Applications folder on the startup disk.

Click continue and agree to the software license agreement if you agree.

Click the “Show All Disks…” button.

Select a blank disk on which to install.

Click the Customize button.

Select the Server Software package.

Unfortunately that isn’t true. It only works if you are already running Lion Server!!! Here is what you need to do.

Assuming you have a disposable Snow Leopard client on volume A and have a blank volume B.

  1. Boot into Snow Leopard client.
  2. Use disk utility to erase volume B
  3. Download both the Lion Client app and the Lion Server app from the app store.
  4. They will be place in you /Applications folder
  5. Run the Lion Client app, when asked press “Show all disks” then select install on Volume B.
  6. Unlike what Apple say the customise button will stay greyed out and it will ignore the Server app.
  7. During the install ignore the option to migrate (This is a client only migration).
  8. Once Lion Client is installed run the Server App to install the server component
  9. Copy the Lion Client app and the Lion Server app from the volume A /Applications to the new Lion Server /Applications directory.
  10. Use disk utility to erase volume A
  11. Run the Lion Client app, when asked press “Show all disks” then select install on Volume A.
  12. This time what Apple say will be true. The customise button will be enabled and you will be able to select the Server component to install.
  13. Connect the mac mini in target disk mode and during the install you will be invited to migrate from another server.

This guide to hosting Lion software updates on a Snow Leopard Server is correct and useful.

Installing grub2 on GNU/Linux Software Raid

I have been setting up a two machines with software raid to use as Xen virtual environments. The two machines have 5 and 4 500GB disks. I decided to run Gentoo as the Dom0  OS because there is lots of good documentation for it and it has always been my favorite GNU/Linux distribution. The install of the OS and xen is easy. I opted for the latest Xen 4.0.1rc3-pre code. Just emerge xen and xen-tools to get all the prerequisites and the unmerge them and build the latest source. Creating the RAID arrays was also easy. I did the following.

Netgear ReadyNAS Pro

I bought one of these because I keep running out of disk space. With the ability to store 12Tb, I thought it might keep me going for some time to come.

It allows you to build raid 0,1 and 5 arrays and Netgear’s own X raid something or other. Unfortunately, it doent allow striping and mirroring. It  is compatible with OS X and supports AFP shares and Timemachine as well as iscsi as I mentioned earlier. However, the GUI is a bit flaky and didn’t seem to like Initiator iqn’s at all. If you download the root ssh plugin you can access the box as root over ssh and look at what it is actually doing.

iscsi config is held in /etc/ietd.conf

Target iqn.2010-2.taurus.sinodun.com:calendarserver
 Lun 0 Path=/e/calendarserver,Type=fileio,ScsiSN=RN293R60037B-003,IOMode=wb
 HeaderDigest CRC32,None
 DataDigest CRC32,None
 IncomingUser user xxxxxxxxxxxx
 InitiatorIQN iqn.2010-02.com.sinodun.hydra:calendarserver

Target iqn.2010-2.taurus.sinodun.com:collaboration
 Lun 0 Path=/e/collaboration,Type=fileio,ScsiSN=RN293R60037B-001,IOMode=wb
 HeaderDigest CRC32,None
 DataDigest CRC32,None
 IncomingUser user xxxxxxxxxxxx
 InitiatorIQN iqn.2010-02.com.sinodun.hydra:collaboration

Firstly their Target IQNs don’t look like the spec described on wikipedia – I don’t know if it is Netgear or Wikipedia that is wrong here and don’t care as this doen’t seem to break anything.

The real problem in the Initiator IQN – I had to add this by hand and it gets stripped out of every entry in the file every time a new iscsi target is created and at other random times. According to the Netgear web GUI theses are needed for persistent reservation support.

However, once it is working it seems nice and stable. If your disks don’t mount just go and check those Initiator IQNs.

OS X Server

I have recently bought one of the new Mac Mini Servers, partly because I like everything mac and partly because I wanted to try OS X Server for my business.

First impressions are great. Apple have taken the best (or very good) OSS and created a nice, if somewhat basic GUI to sit on top. You can of course still go and edit the configuration by hand if need be.

Unfortunately, the graphics card failed in the first unit, however Apple were very good and I had a new unit in a couple of days. This got me thinking. Normally if I wanted to send a computer back for repair or replacement I would remove the disks but with a mac mini you have to prise it open with a paint scraper. Not something I really want to be doing to a box which is still under warranty.

So, when the new one arrived, I decided to take advantage of my Netgear ReadyNAS Pro NAS box’s (of which more later) ability to do iscsi and along with the globalSAN iSCSI Initiator added disks for each service that could contain sensitive data.  This took some time to get working, mostly due to issues with the Netgear but I now have all data on hot swap mirrored disks and the mac mini could go back to apple with no sign of sensitive data.

Developing an engine for OpenSSL

For fun I thought I would see how hard it is to write an engine for OpenSSL. There are several existing ones that you can look at. I started by seeing how the opensc engine worked. This code shows the first step.

#include <stdio.h>
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/objects.h>
#include <openssl/engine.h>

static int bind_fn(ENGINE * e, const char *id)
{
  if (!ENGINE_set_id(e, "simple") ||
      !ENGINE_set_name(e, "simple engine")) {
    return 0;
  } else {
    return 1;
  }
}

IMPLEMENT_DYNAMIC_CHECK_FN();
IMPLEMENT_DYNAMIC_BIND_FN(bind_fn);

Compile it like this

gcc -c -fpic simple_engine.c
gcc -shared -o simple_engine.so simple_engine.o

Make openssl.cnf look like this

openssl_conf            = openssl_def

[openssl_def]
engines = engine_section

[engine_section]
simple = simple_section

[simple_section]
engine_id = simple
dynamic_path = /path/to/simple_engine.so
init = 0

[req]
distinguished_name = req_distinguished_name

[req_distinguished_name]

Run OpenSSL and see your results

$ openssl engine
(padlock) VIA PadLock (no-RNG, no-ACE)
(dynamic) Dynamic engine loading support
(simple) simple engine

Of course it doesn’t do anything useful yet. But it is a start.