Persistent Block Storage (Volumes)
Creating resilient NVMe block devices, attaching to instances, and formatting file systems.
Persistent Block Storage
Volumes in microsrv are highly available block devices built on high-speed NVMe flash arrays with background data replication across physical storage nodes.
Essential Properties:
- Volume data persists independently across instance shutdowns, container restarts, and live migration cutovers.
- Volumes can be attached to virtual machines as raw block devices (
/dev/vdb) or to Containers as the backing store for Stateful OverlayFS. - A block volume can be attached to one virtual machine or container instance at a time.
Provisioning & Mounting Steps
- Navigate to Console -> Volumes.
- Click Create Volume and pick a size in 8 GiB increments: 8, 16, 24 or 32 GiB.
- From the volumes list, click Attach to VM and select your target instance.
Once attached, the volume appears inside the guest OS as a raw block device (typically /dev/vdb):
# Verify attached block storage devices
ubuntu@demo-web:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
vda 252:0 0 30G 0 disk
├─vda1 252:1 0 29.9G 0 part /
vdb 252:16 0 100G 0 disk
# Format as ext4 and mount:
ubuntu@demo-web:~$ sudo mkfs.ext4 /dev/vdb
ubuntu@demo-web:~$ sudo mkdir -p /mnt/data
ubuntu@demo-web:~$ sudo mount /dev/vdb /mnt/data[!WARNING] Always unmount the volume inside the guest OS (
sudo umount /mnt/data) before issuing a detach command in the console to prevent file system corruption!