installing Dell bios update on 64-bit linux

Unlike many motherboard OEMs, Dell releases BIOS updates that can be executed from linux.  Unfortunately, a portion of these updates are precompiled binaries for 32-bit linux only.  Here's how I made the BIOS update work for my Precision T5400.

Get the update:

wget https://downloads.dell.com/FOLDER00493899M/1/T5400A11.bin
md5sum T5400A11.bin
# should be 11a13eae55e01ca5aaadda459b78cf2a
chmod a+x T5400A11.bin

Like many vendors of proprietary software in the world of FOSS, the update takes the form of a short shell script that extracts and unzips a precompiled binary from itself.  All the work is done in that binary.  Unfortunately, when you try to run it under a 64-bit Debian install, you'll get something unhelpful like:

./flash: No such file or directory

So here's the solution to run this binary under 64-bit Debian:

dpkg --add-architecture i386
aptitude update
aptitude install libc6:i386 libstdc++6:i386 zlib1g:i386

Now you should be able to run the update!

./T5400A11.bin

LACP port bonding with DHCP on debian stretch

Finding information on LACP port bonding can be tricky.  It seems there's a decent guide published every couple years, but then the code changes and the information no longer really applies.

And creating a bonded interface with DHCP is even trickier.  You could solve it this way, if you wanted to cop out.  But copping out is for out coppers, and everyone knows that that ain't me.

So we're going to configure LACP port bonding (aka 802.3ad) on our brand new install of debian stretch (at the time of this writing, stretch is nearly identical to jessie, so this guide ought to work for jessie for a few years).

1. aptitude install ifenslave
   echo 'mii' >> /etc/modules
   modprobe bonding
   
   This gives us the ability to create bond interfaces.
   
   
2. vi /etc/network/interfaces
   
   And make sure the contents look something like this:
   
   source /etc/network/interfaces.d/*
   
   # Loopbackz
   auto lo
   iface lo inet loopback
   
   # Enslave these interfaces
   allow-hotplug eth0
   allow-hotplug eth1
   
   # The bonded interface
   auto bond0
   iface bond0 inet dhcp
       bond-slaves eth1 eth0 # order matters!  the first listed interface is the one whose mac is used
       bond-mode 802.3ad
       bond-miimon 100
       bond-downdelay 200
       bond-updelay 200
       bond-lacp-rate 1
       bond-xmit-hash-policy layer2+3
   
   
3. Reboot.  Or muck around with /etc/init.d/networking restart, ifconfig INTERFACE DOWN|UP, etc.
4. If the ifconfig output looks good, and the output from cat /proc/net/bonding/bond0 looks good, and you have network connectivity, then you've done it!

Go have a cold beer, you've earned it.