Block Storage Overview

Block Storage is a redundant and distributed block device implementation for Exoscale Compute instances.

Terminology

• Volume: a single storage device that is partitioned and formatted to store directories and files.
• Snapshot: a storage snapshot is the state of a volume at a particular point in time. It provides the ability to create new volumes with the state of the current volume at that specific point in time.

Features

The following list presents the core characteristics for Block Storage volumes:

• Block size: 4KiB fixed.
• Replication: minimum 2 copies of the data within the same Zone.
• Volume snapshots: a snapshot can be used as a base to fork another volume from it. It is not possible to directly download or export a snapshot.
• Type: block devices are ReadWriteOnce, each volume can only be attached to a single instance at a single point in time. It can be detached from a running instance and reattached to another instance of the same Zone.

Availability

The Block Storage offering is currently available exclusively from:

• at-vie-1
• ch-gva-2
• ch-dk-2
• de-fra-1

Limitations

The following table shows which limits are enforced on Block Storage usage. It also highlights some of the characteristics of the product:

In addition the default Organization Quotas are set and can be expanded upon request:

As block storage volumes expose a block size of 4KiB, some software that incorrectly assume a smaller block size might not work. This issue can be circumvented by using a compatibility layer in your instance like dm-ebs on linux.