loop and qemu-nbd flexvolume drivers for kubernetes

This driver provides you next options:

• loop - simple loopback device
• qemu-nbd - same like loopback but using qemu-nbd
• sheepdog - sheepdog support (experimental)

Basicly this driver allows you to use large files on shared filesystem as vrtual drives for your containers.

It can be a necessary step if your containers have a lot of small files and you want to avoid excessive access to metadata of shared filesystem.

There is also experimental sheepdog support.

Features

• Automatic volumes allocation and creation
• Multi-mount protection (for ext4 only)
• Checking for shared filesystem (is mounted or no)

Requirements

• Kubernetes: >=1.9 version

loop mode requirements:

• Common filesystem mounted on each node in one place

qemu-nbd mode requirements:

• Common filesystem mounted on each node in one place
• qemu-img and qemu-nbd installed in the system

sheepdog mode requirements:

• Sheepdog cluster
• dog, qemu-img and qemu-nbd installed in the system

Limitations

• Only raw images currently supported.
• Each volume will formatted with simple file system, so only one pod can use it in r/w mode.

Quick start

This command will install all the drivers on your nodes:

kubectl apply -f https://raw.githubusercontent.com/kvaps/flexvolume-qemu-nbd/master/flexvolume-qemu-nbd.yaml

Usage

There is few examples, check dir for more detail.

Options

basic options:

• kubernetes.io/fsType - filesystem type (default: ext4)
• mmp - enable multimount protection (default: true)
• size - specify the volume size, if set driver will create volume in filesystem
• fsck - run filesystem check before mount (default true)
• mmpUpdateInterval - specify the multimount protection interval (default 5)
• fsckOptions - fsck options for checking filesystem (default a)

loop and qemu-nbd specific options:

• share - path to your share, driver will return error if it not mounted in the system
• file - releative path to your volume, from / or from share if set

sheepdog specific options:

• vdiname - volume name in sheepdog cluster
• prealloc - preallocate all the data objects
• hyper - create a hyper volume
• copies - specify the data redundancy level
• address - specify the sheepdog node address (default localhost)
• port - specify the sheepdog daemon port
• block_size_shift - specify the bit shift num for data object size

License

• flexvolume-qemu-nbd is under the Apache 2.0 license. (See the LICENSE file for details)