xfsvol 📂
Docker Volume Plugin for managing local XFS-based volumes
Quickstart
- Create a mountpoint at
/mnt/xfsand a directory/mnt/xfs/volumes.
For testing purposes this mountpoint can be a loopback device (note: use a loopback device for testing purposes only).
sudo dd if=/dev/zero of=/xfs.1G bs=1M count=1024
sudo losetup /dev/loop0 /xfs.1G
sudo mkfs -t xfs -n ftype=1 /dev/loop0
sudo mkdir -p /mnt/xfs/volumes
sudo mount /dev/loop0 /mnt/xfs -o pquota- Install the plugin
docker plugin install \
--grant-all-permissions \
--alias xfsvol \
cirocosta/xfsvol
docker plugin ls
ID NAME DESCRIPTION ENABLED
06545b643c6a xfsvol:latest Docker plugin to manage XFS-mounted volumes true
- Create a named volume
docker volume create \
--driver xfsvol \
--opt size=10M \
myvolume1
- Run a container with the volume attached
docker run -it \
-v myvolume1:/myvolume1 \
alpine /bin/sh
dd if=/dev/zero of=/myvolume1/file bs=1M count=100
(fail!)
- Check the volumes list
docker volume ls
DRIVER VOLUME NAME
xfsvol:latest myvolume1 (1.004MB)
local dockerdev-go-pkg-cache-gopath
local dockerdev-go-pkg-cache-goroot-linux_amd64
local dockerdev-go-pkg-cache-goroot-linux_amd64_netgo
and the xfsvolctl utility:
sudo /usr/bin/xfsvolctl ls --root /mnt/xfs/volumes/
NAME QUOTA
ciro 1.004 MB
xfsvolctl
This tool is made to help inspect the project quotas created under a given root path as well as create/delete others. It's usage is documented under --help:
xfsvolctl --help
NAME:
xfsvolctl - Controls the 'xfsvol' volume plugin
USAGE:
xfsvolctl [global options] command [command options] [arguments...]
VERSION:
0.0.0
COMMANDS:
ls Lists the volumes managed by 'xfsvol' plugin
create Creates a volume with XFS project quota enforcement
delete Deletes a volume managed by 'xfsvol' plugin
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help
--version, -v print the version
Under the hood
$ sudo mkdir -p /mnt/xfs/tmp/bbb
$ sudo strace -f xfsvolctl create \
--root /mnt/xfs/tmp/bbb \
--name ccc \
--size 1024 \
--inode 1024
stat("/mnt/xfs/tmp/bbb", {st_mode=S_IFDIR|0755, st_size=6, ...}) = 0
unlinkat(AT_FDCWD, "/mnt/xfs/tmp/bbb/backingFsBlockDev", 0) = -1 ENOENT (No such file or directory)
mknodat(AT_FDCWD, "/mnt/xfs/tmp/bbb/backingFsBlockDev", S_IFBLK|0600, makedev(7, 0)) = 0
quotactl(Q_XSETQLIM|PRJQUOTA, "/mnt/xfs/tmp/bbb/backingFsBlockDev", 1, {version=1, flags=XFS_PROJ_QUOTA, fieldmask=0xc, id=1, blk_hardlimit=0, blk_softlimit=0, ino_hardlimit=0, ino_softlimit=0, bcount=0, icount=0, ...}) = 0
...
mkdirat(AT_FDCWD, "/mnt/xfs/tmp/bbb/ccc", 0755) = 0
open("/mnt/xfs/tmp/bbb/ccc", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFDIR|0755, st_size=6, ...}) = 0
ioctl(3, FS_IOC_FSGETXATTR, 0xc4201a95e4) = 0
ioctl(3, FS_IOC_FSSETXATTR, 0xc4201a95e4) = 0
quotactl(Q_XSETQLIM|PRJQUOTA, "/mnt/xfs/tmp/bbb/backingFsBlockDev", 2, {version=1, flags=XFS_PROJ_QUOTA, fieldmask=0xc, id=2, blk_hardlimit=2, blk_softlimit=2, ino_hardlimit=1024, ino_softlimit=1024, bcount=0, icount=0, ...}) = 0
[pid 6833] ioctl(2, TCGETS, {B38400 opost isig icanon echo ...}) = 0
// retrieving (ls)
[pid 8609] quotactl(Q_XGETQUOTA|PRJQUOTA, "/mnt/xfs/tmp/ddd/backingFsBlockDev", 2, {version=1, flags=XFS_PROJ_QUOTA, fieldmask=0, id=2, blk_hardlimit=8, blk_softlimit=8, ino_hardlimit=0, ino_softlimit=0, bcount=8, icount=104, ...}) = 0