Little bits of information someone might find useful, or not
CephFS is a very versatile, scaleable, distributed file system. I’ve gradually been scaling out my Ceph cluster and now have 65TB across 11 nodes, which in fairness is quite small as Ceph clusters go! One downside of CephFS however is that support for Windows clients is very lacking at the moment. There is currently some very early work ongoing to...
The recent 1.6 release of Kubernetes strongly encourages switching etcd to etcd3. However, if you have an existing etcd2 cluster, the documentation CoreOS provides on upgrading it is less than helpful. Although it documents the upgrade procedure, it doesn’t tell you how to actually switch from running etcd2 to etcd3 – simply saying to drop in the new etcd3 binary in...
Containers are great, up until you need to persist storage beyond the potential lifetime of the container. In a single Dockerised setup, this might be easily solved through the use of host volumes but that’s not really a feasible method on larger orchestrated container setups such as Kubernetes. Luckily though, this is easily solved through the use of remote persistent volumes....
Baby Jumbo Frames (as defined in RFC 4638) are a pretty useful feature. In short, they allow you to have a standard 1500 byte MTU on PPPoE connections. Normally, due to the 8 byte PPPoE header the connection is reduced to a MTU of 1492 bytes. Baby Jumbo Frames allows for the MTU of the underlying interface to be increased to...
Thin-provisioned disks can be pretty useful in ESXi. There’s no need to pre-allocate storage or have huge amounts of unused, but allocated, storage sitting idle. However, whilst thin-provisioned disks can semalessly grow themselves, they cannot be shrunk as easily. For example, if you wrote 10GB of data to a thin-provisioned disk and then deleted it, although from the VM’s perspective...
