Author Archives: bolt

Upgrading the Vostro 1700 to beyond maximum specs

WARNING: This post is very specific to an old laptop, probably only interesting to anyone looking to upgrade such a machine. I warned you. I have an unhealthy obsession with “maxing out” machines, especially older ones. It was time for the chunky old Vostro 1700 that now runs Windows 7 instead of the version of […]

Figuring out which session is blocking a query on Microsoft SQL Server (query suspended)

I was recently debugging a case where a customer’s installation was hanging due to a database lock. The issue turned out to be that the database was not set to a default transaction level of READ COMMITTED SNAPSHOT, which the product expects. Regardless, while troubleshooting the issue, I stumbled upon a very useful SQL query […]

Using IPv6 SLAAC with IP forwarding on Debian Stretch (“connect: network is unreachable”, no default gateway)

When configured as a router, for instance for hosting virtual machines with KVM, a Debian machine with a somewhat recent kernel will not listen to router advertisements from others. This makes sense in many cases, but when you have a VM host in your internal network, which only router function is to allow communication to […]

Exim4 line length in Debian Stretch – “Mail delivery failed: returning message to sender”

Exim4 introducted new behaviour in the versions included in Debian Stretch. Suddenly, the RFC max line length of 998 characters is enforced, and emails with lines exceeding this length are returned to sender. For the interested, part of the discussion about this feature is over here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=839147 Anyway, the solution to this issue in Debian […]

Understanding mcelog ECC errors – Which stick of RAM is broken?

Before reading this, please note that much of the information in mcelog is hardware dependent. Your mileage may vary. Memory gone bad So one of the servers, running an X99-WS/IPMI board from Asus, began putting errors into /var/log/mcelog. Thankfully, they were all the same, telling me the following: mcelog: failed to prefill DIMM database from […]