Which (Software-)RAID for NVMe/SSD disks?

Today we ran some tests and benchmarks and while in the past with mechanical hard drives the hit from the overhead of running checksums etc for RAID5 and/or RAID6 was negligible, with SSD it became a factor and with the latest generation Optane disks the difference is just huge. Compare the following numbers taken on … Read more

CloudStack MySQLIntegrityConstraintViolationException: Duplicate entry

We have been seeing many variants of the MySQLIntegrityConstraintViolationException error message in CloudStack (CloudStack Duplicate entry). This can occur when creating or starting a VM or when deleting it, during account setup and during the startup of the management server. The causes can vary, from errors caused by MySQL STRICT_MODE changes to real duplicate entries … Read more

[SOLVED] Unplanned Maintenance Work on the Barracuda Email Security Gateways

Sunday, the 25th of April, 2017 beginning at 07:00 pm till midnight extraordinary updates and unplanned maintenance work had to be carried out on the Barracuda Email Security Gateway (formerly known as Barracuda Spam Firewall) for security reasons. During the update single e-mail messages might have experienced delivery delays, but all messages have been delivered … Read more

Sample Cloud Server Benchmark

Customers frequently ask us to run the bench.sh script to see the basic performance of our cloud instances. Well, here is the benchmark of a single cloud server with 1GB of RAM, 1 CPU Core and 10GB of Storage (SSD; connected using InfiniBand):   ubuntu@benchmark1:~$ ./bench.sh Benchmark started on Mon Nov 14 13:16:33 UTC 2016 … Read more

Complete Live Migration of VMs with High Load

If you are using CloudStack or OpenStack the default behaviour of live migration is configured as launch & pray it will complete. This can cause – and in practice probably will cause – VMs which have a lot of dirty pages to not complete live-migration at all. [section background_repeat=”repeat” background_position=”center top” background_attachment=”static” background_scroll=”none”] This is … Read more

DLM 4.0.6 Upgrade for Ubuntu 16.04 LTS

The version 4.0.4 of dlm (Distributed Locking Manager) currently shipped with Ubuntu 16.04 LTS has a severe bug that causes fencing of a remote host initiated by other clustered components to fail. This can cause an entire cluster to be stuck waiting and/or all cluster nodes disconnecting from the cluster for no reason. This fencing … Read more

.PRO Policy Update

The .PRO domain extension will become unrestricted and open to all registrants, effective from November 16, 2015. .PRO Registry Agreement Renewed Under New Terms This change is a result of the renewal of the Registry Agreement under new terms between the Registry Services Corporation and ICANN. Here’s the renewed Registry Agreement for reference. Domain renewals, … Read more

[SOLVED] Routing issues in Amsterdam

Currently we are experiencing an ongoing software issue on one of our router’s in Amsterdam causing routing issues. Our IP engineering team is investigating this issue together with our hardware vendor. We have already re-routed all paths to an alternative carrier, but should you notice slow connectivity issues with your server, please contact us so … Read more