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.
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
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
If you are seeing the neighbor table overflow message in the dmesg log it means that the ARP cache of your server has run out of space. This can happen if you host multiple cloud servers and or massively scale Kubernetes, Proxmox or other virtualization solutions on one physical server, as every VM / Pod / … Read more
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
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
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
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
Since the 8th of December 2015 new VirtIO drivers from SuSE show up in the Windows Update as an optional update. Please do not install those drivers as the Cloud Servers will crash and not boot up correctly (BSOD). Please keep the default drivers or if you really wish install only the RedHat certified VirtIO … Read more
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