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


  • Volume: a single storage device that is partinonned 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.


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.


The Block Storage offering is currently available exclusively from:

  • ch-gva-2
  • at-vie-1


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

Usage Limit
Maximum number of volumes attached to an instance 5
Maximum number of snapshot per volume 20
Maximum volume size 10 TiB
Minimum volume size 10 GiB
Maximum read IOPS per volume 5K
Maximum write IOPS per volume 5K
Maximum bandwidth per volume 200 MiB/s
Minimum instance size to attach a volume Small (like SKS)
Supported service offerings All

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

Usage quota
Volumes per org 1000
Overall provisioned volume size 20 TiB