Author: David Goodwin

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Script to fix NFS (Debian Squeeze + Backports bits)

I have a NFS server running Debian Squeeze. Additionally it’s using the 3.2.x kernel from backports, and the nfs-kernel-server from backports too.

Sometimes NFS breaks, and gives helpful messages like :

mount.nfs: connection timed out

or just:

Stale NFS handle on clients.

 

While I’m confident that my /etc/exports and other configuration files are correct, it still insists on misbehaving.

Below is a random shell script I seem to have created to fix the NFS server –

#!/bin/bash
set -e
/etc/init.d/nfs-kernel-server stop
/etc/init.d/nfs-common stop
/etc/init.d/rpcbind stop

rm -Rf /var/lib/nfs
mkdir /var/lib/nfs
mkdir /var/lib/nfs/v4recovery /var/lib/nfs/rpc_pipefs

for f in /var/lib/nfs/etab \
/var/lib/nfs/rmtab \
/var/lib/nfs/xtab; do
[ -e $f ] || touch $f
done

/etc/init.d/rpcbind start
sleep 2
/etc/init.d/nfs-common start
sleep 2
/etc/init.d/nfs-kernel-server start

echo "NFS may now work"

exportfs -f

Yes… “NFS may now work” … that sums it up about right.

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Spam and Comic Sans.

Today, I received a spammy email from an unknown golf club. There was no obvious unsubscribe link or instructions, so I blindly replied with :

Hi,
Please remove 'xxxxxx' from your mailing list; we've no interest in golf…
Thanks,
David

 

They replied with :

REMOVED OK

But it was actually :

<FONT color=#0000ff size=4 face=”Comic Sans MS”>REMOVED OK</FONT>

i.e.

comic sans thank you
So I had to reply with :

<div style=”text-align: center;”><u style=”font-size: 144px; color: rgb(245, 236, 0); font-family: ‘Comic Sans MS’; “><b>Thank you!1!!</b></u></div>

Horrible yellow comic sans thing

 

I fear the intricacies of my reply were lost on them.

 

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A few months with a Nexus 4

So, I’ve had a Nexus 4 for a while now … here’s some findings :

  1. The phone is symmetrical (or very close to it) – so I often pick it up the wrong way around – at least with an iPhone there was a button at the bottom which acts as an easy to feel guide so you can pick it up correctly in the dark. Adding a case to it helped.
  2. You need a bumper/case for it… mine cost £3 on Amazon or something … without one it’s too slippery/slides off everything.
  3. The battery life is both good and bad – while not in use, it lasts ages; but it has a big screen – so playing games or watching Netflix on it, will really kill the battery. I’m using Battery Widget Reborn – which does a great job at turning wifi/sound/gps etc all off overnight which helps a bit.
  4. I came to use the Nexus 4 from using an iPhone – my main like is widgets – having something that updates in real time on your desktop (why did the iOS weather app never display today’s symbol?) is great.
  5. I miss having a count of notification numbers next to the launch icons.
  6. I kind of miss iMessage – in so far, as I wish Google had something similar. At the moment there is gtalk, google plus chat (or something) …. which don’t seem to be totally integrated … and I have to supplement this with WhatsApp which not all that many people use (here’s hoping for Google Babble)
  7. I wish the Bluetooth integration was better – not being able to see track names etc on the £30 Sony MW600 thing I bought kind of sucks. I’m fairly sure that if my car was good enough to have a bluetooth capable radio, then I wouldn’t see any track names from it either :-/
  8. I like Navigation – I’ve used this a number of times and it does a good job. If only I could make it’s voice louder though. Perhaps this is why I need a car radio with blue teeth.
  9. I’ve not noticed that I’m missing any apps from iOS which aren’t available on Android – but I suspect I only regularly use ~10 (k9 mail, world war, twitter, whatsapp, bbc news, facebook, gallery, nagios, kashdroid, ZombieRun!).
  10. The screen is a little too big to use it with only one hand.
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Virtualbox 4.2 VM autostart on Debian Squeeze & Wheezy

One new feature of VirtualBox 4.2 is that it has support for auto-starting vm’s on bootup of the host server (via init etc). This means I can remove my hackish ‘su – vbox -c “VBoxHeadless –startvm VMName &”‘ additions in /etc/rc.local, and the VM’s will also hopefully be terminated gracefully on shutdown.

The docs/guides online which I could find were a bit cryptic, or incomplete, so here’s what I ended up doing :

Continue reading “Virtualbox 4.2 VM autostart on Debian Squeeze & Wheezy”

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MySQL update/write query analysis (query profiling)

Do you have a slow MySQL update/insert/delete query?

Obviously, for ‘SELECT’ queries you can prepend the query with “EXPLAIN ” – however that doesn’t work for the other query types (UPDATE/INSERT/DELETE).

So, one solution which may explain why the query is slow is to turn on MySQL’s profiling functionality, like in the following example :
Continue reading “MySQL update/write query analysis (query profiling)”