The Blog of Greg

I use evolution for email on my desktop. For the last few months every now and then the whole thing would hang up once in a while with a bunch of stuck processes. There always seemed to be one that said “Saving user interface state”. Recently this began happening more often to the point that it became unusable. Finally I built an RPM with the latest stable version, got a backtrace and filed a bug at gnome bugzilla. The response was super quick and apparently it’s a known issue. The answer for me was:

Try Edit -> Preferences -> Mail Preferences -> Headers (tab)

Make sure this option is unchecked:

[ ] Show the photograph of sender in the message preview

Link to the bug is here: https://bugzilla.gnome.org/show_bug.cgi?id=692727

Many thanks to Matthew Barnes for the quick fix that has made my emailing painful for a long time.

Hopefully this saves someone some time. I have an old MSI X320 laptop that I was having trouble with to the extent I was trying to justify buying a brand spanking new MACbook pro retina to replace it. Alas I found out how to make it work just fine. xubuntu 12.10 pretty much installs out of the box. You then just need to disable the sdhci module by putting sdhci_pci.blacklist=yes in the boot command line and iwconfig wlan0 power off in /etc/rc.local to stop the power saving on the wireless connection that periodically hangs the machine and makes wireless access very spotty.

Recently I’ve gotten to try out samba4 at 2 different clients. Here were the scenarios:

client1: wants to migrate from a Windows 2003 SBS AD to something more open (ie: not windows). I initially thought of just bringing everything into OpenLDAP but samba4 looked like it would be less disruptive while still meeting the goals. This was my first try setting up samba4. In this scenario I just built a samba4 alpha, joined is at a DC to the domain, transferred all the roles to it and then demoted the old windows DC and removed it. Although I did try the bind DLZ and the internal DNS servers, for thgis client the best solution was to consolidate DNS on an existing bind server so I moved the zone there and let the DCs update it.This transition went very well aside from some delays figuring out how AD works exactly. There is one issue in this case however, and that is UID mappings. Because Win2003 did not have any RFC2307 schema attributes there is no where to store these in the active directory. Would have either needed to add  SFU before the migration (too much windows!) or extend/migrate the schema after the fact (will try this one).

client2: wants to migrate from an LDAP backed  Samba 3.x hosted domain to a Windows AD infrastructure. As there is no obvious way I know of to import all the LDAP data into a windows AD, I thought it would be good to just run the builtin upgrade procedure to migrate from samba3 to samba4 (using samba-tool domain   samba3upgrade), then join a windows AD DC to that realm and demote the samba4 server leaving just the desired windows infrastructure. This went fairly well, I just followed the wiki article (http://wiki.samba.org/index.php/Samba4/samba3upgrade/HOWTO) and the only real problem was some accounts that the migration script did not handle so I removed those and eventually it want through. There was one other little problem. If you get:

Failed to modify account record CN=auser,CN=Users,DC=domain,DC=local to
set user attributes: Unsupported critical extension 1.3.6.1.4.1.7165.4.3.20

To fix this I had to patch the source code. The other issue is that UID/GID mappings are not migrated by the upgrade process so I had to write a script to grab them from the old LDAP and update them in the new AD. Because it’s a base 2008 schema the attributes are there but need to be populated.

Overall my first experience with samba4 was great!

A client recently decided to use Amazon’s Simple Email Service to send email from their website. All the articles I found to set that up involved configuring an stunnel connection to port 465 of the amazon relay host. That seems totally unnecessary to me. So here is what I did:

I added the following to /etc/postfix/main.cf

elayhost = email-smtp.us-east-1.amazonaws.com:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/password
smtp_sasl_security_options =
smtpd_sasl_path = smtpd
smtp_sasl_type = cyrus
smtp_tls_security_level = may

Next you need to create the password file (/etc/postfix/password) to enable authentication, the format is:

email-smtp.us-east-1.amazonaws.com:587 SMTP_USERNAME:SMTP_PASSWORD

The SMTP_USERNAME and PASSWORD can be obtained by creating them in The AWS console under SES/SMTP.

then create a hash out of it with:

postmap hash /etc/postfix/password < /etc/postfix/password

restart postfix and your mail should now relay through SES

I’ve had a recurring discussion lately with people who are wanting to either implement or improve their build processes. The conversation is essentially the same regardless of which SCM they are using (CVS, Subversion, Clearcase or Perforce). There seems to be a strong tendency to shift away from the current tool because that will somehow “fix everything”. I’ve had the same discussion quite frequently about which web development framework to use. What most people seem to miss is that in most cases a tool is just a tool. Oh sure, you definitely want to pick the right tool for the job but if you have no defined process in Clearcase, then simply switching to perforce is not going to help you. A hammer can be used to break down a wall or build one. Similarly if you write crap code in PHP then simply switch to RoR or python just gives you differernt syntax to write crappy code in and a different set of implementation issues.

You need to look beyond the tool or the implementation to the root of the problems and fix those.

When my wife moved out last summer she took a stained glass panel that her father had made from the powder room. Fair enough but it didn’t do anything for the decor of the powder room to have a door sans glass in it. My friend Oksy showed up in January with an amazing replacement. See it here. Pretty nice eh?

Well this is it. I’ve finally got a blog. No idea what to write though. Stay tuned, I’ll think of something.

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