Author Archives: bolt

Making Windows keep the system clock in UTC

Some hypervisors for virtual machines do not properly support sending a fake system time to the guest operating system, thus making Windows guests display the wrong time if their timezone is set to anything except UTC. This happens because Windows, by default, keeps the system clock set to the local time. This is stupid. The […]

Finding the most expensive recent SQL queries on SQL Server

Mostly a note to self, original source here. SELECT TOP 10 SUBSTRING(qt.TEXT, (qs.statement_start_offset/2)+1, ((CASE qs.statement_end_offset WHEN -1 THEN DATALENGTH(qt.TEXT) ELSE qs.statement_end_offset END – qs.statement_start_offset)/2)+1), qs.execution_count, qs.total_logical_reads, qs.last_logical_reads, qs.total_logical_writes, qs.last_logical_writes, qs.total_worker_time, qs.last_worker_time, qs.total_elapsed_time/1000000 total_elapsed_time_in_S, qs.last_elapsed_time/1000000 last_elapsed_time_in_S, qs.last_execution_time, qp.query_plan FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) qt CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp ORDER BY qs.total_logical_reads DESC — logical reads […]

Creating a local Certificate Authority using OpenSSL

I was recently tasked with creating a local CA for a project, where we needed to verify custom client certificates, have the ability to revoke them at will, and we wanted to add additional custom fields to the certificates. Cool. The first stop after searching a bit was this excellent howto by Jamie Nguyen. There’s […]

Shrinking a Raspbian installation and re-enabling auto expanding for distribution of customized images

UPDATE: See the automated script at https://blog.dhampir.no/content/script-for-creating-a-compressed-image-file-from-a-raspbian-sd-card Raspbian, by default, expands to fill the SD card it finds itself on, the first time it boots. After having customized an image to your liking it would be favourable to avoid copying 16 gigabytes of data, or however large your chosen SD card is, each time you […]