In the ongoing 8.4. efforts we’re currently testing the effects of using early write submits – both to local storage and to the peer node(s).
Ie., when DRBD can guess in advance that write requests will soon be sent, it can prematurely send the data pages to the other node; so if the application then does write to storage, all that is needed is a small “
do it” packet. The smaller packet size can be transmitted over the (much faster) meta-data DRBD connection, and so reduces latency by a fair amount.
See this performance improvements in a trial run:
Early-write performance improvements
For configuration there’s a new item in the
early-write, using a time value in the usual tenths-of-a-second unit. Eg.
10 will cause DRBD to send the data one second before the application tries to write it.
You can expect that feature in the next proprietary 8.4.5 release of DRBD, so stay tuned!
In the last blog post about DRBDmanage we mentioned
Initial setup is a bit involved (see the README)
… with the new release, this is no longer true! Continue reading
As already announced in another blog post, we’re preparing a new tool to simplify DRBD administration. Now we’re publishing its first release! Continue reading
One of the projects that LINBIT will publish soon is
drbdmanage, which allows easy cluster-wide storage administration with DRBD 9. Continue reading
As an update to the earlier blog post, take a look below. Continue reading
The threading model in DRBD Proxy 3.1 received a complete overhaul; below you can see the performance implications of these changes. Continue reading
A question we see over and over again is
umount so slow? Why does it take so long?
Part of the answer was already given in an earlier blog post; here’s some more explanation. Continue reading
For the people who don’t already have DRBD 8.4.3 deployed: here’s another good reason — Performance. Continue reading
Recently we’ve upgraded one of our virtualization clusters (more RAM), and in the course of this did an upgrade of the virtualization hosts from Ubuntu Lucid to RHEL 6.3 — without any service interruption. Continue reading
The Raspberry PI is a small ARM computer (hardware specifications in wiki, outline and FAQs). Of course, you can build a cluster with it! Continue reading