Longhorn Block Storage vs. Tencent Cloud Block Storage

Longhorn is performing well as storage for databases and in almost any solution that uses exclusive access to volumes (ReadWriteOnce in Kubernetes nomenclature). When write access is required from many clients (ReadWriteMany) Longhorn Block Storage covers its volumes with NFS (file-based) access. Longhorn Block Storage also is well fitted in every architecture where data security (snapshots, backups, multiple replicas) is more important than access speed (in terms on IOPS and MiB/s).

• Creates read-write many (RWX) volumes
• Longhorn Block Storage is an easy to deploy solution
• Scheduled and on-demand volume snapshots can be created using web GUI
• Volume backups can be stored offsite on any S3 compatible storage solution
• Backups and snapshots can be restored using web GUI

• ReadWriteMany Longhorn volumes are still using NFS (file-based) protocol in the core.
• Using iSCSI as main protocol instead of FC ties Longhorn to Ethernet-based LAN which is in most architectures much slower that FC-based SAN.
• Longhorn could implement S3 as alternative access protocol to its volumes.
• Backups, and snapshots configuration could be configured at each volume-level by administrators (maybe from additional CRD object?), because currently is configured at storage-class level which is not granular enough.

Longhorn is mature software defined storage solution that is still developed and receive new functionalities. From the beginning every Longhorn volume have multiple (at least two) replicas, can leverage manual or automatic snapshots and backup to external S3 volume. Longhorn provides nice and clear GUI for administrators, but also can be managed from CLI.

GlusterFS was first Persistent Storage solution used in our Kubernetes-based clusters. It is file-based what in some usages led us to many data corruptions. CEPH is object-based persistent storage which can be used as file-based Persistent Storage in Kubernetes. It is also is much more resource-hungry than other solutions including Longhorn. Dell PowerScale (or Isilon) is a hardware-software solution, that provides volumes that can be accessed by file-based NFS and CIFS protocols. Recently was added access to its volumes with object-based S3 protocol. Longhorn is in the middle. It is block-based, it is build on industry standards like iSCSI, performs very well on 10Gbit or faster LAN and commodity hardware (or in virtual machines)

• It has provided a highly available storage solution for almost all our Kubernetes deployments
• We can deploy new app versions with peace in mind because we have working data backups
• Application development is faster because devs can play with data and easily restore it when needed