Have you ever wanted to do a file based backup of your data without impacting
your application, and without stopping your HA replication? Here is one
possible method. Continue reading
Every now and then we get asked “why not simply use a mirrored SAN instead of DRBD”? This post shows some important differences. Continue reading
DRBD 8.4.1 introduces a new feature:
read-balancing, which is configured in the
disk section of the configuration file(s). This feature enables DRBD to balance read requests between the Primary/Secondary nodes. Continue reading
Stumbling upon the Holy time-travellin’ DRBD, batman! blog post there’s only one thing to be said …
Be strict in what you emit, liberal in what you accept
is simply not true when dealing with mission-critical systems.
It’s ok to be alerted on upgrading a machine because the “old, working” RegEx that did the parsing doesn’t match anymore; it’s not a problem to get an email when someone adds the 100th DRBD resource and causes the grep to fail; and so on. Continue reading
From time to time we get asked things like this:
I want to use a 10TiB volume with DRBD, is that supported”?
The easiest way to answer things like that is to say look for yourself on the public DRBD usage page – the biggest public device size is ~220TiB, so go figure Continue reading
DRBD tries to ensure data integrity across different computers, and it’s quite good at it.
But, as per the old saying Trust, But Verify it might be a good idea to periodically test whether the nodes really have identical data, similar to the checks that are done for RAID sets. Continue reading
The sync-rate controller is used for controlling the used bandwidth during resynchronization (not normal replication); it runs in the
SyncTarget state, ie. on the (inconsistent) receiver side. Continue reading
The TL;DR version: don’t use
data-integrity-alg in a production setup. Continue reading
For people using the VIM editor I’ve got two small tips when editing Pacemaker configurations:
Use syntax highlight. This helps to see unmatched quote characters easily. Whether it’s too colorful can be discussed, though
A current version can be found here, and the mailing list post is here.
For correlating resource names I recommend the Mark plugin. Continue reading