Redundancy options for managed disks

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Applies to: ✔️ Linux VMs ✔️ Windows VMs ✔️ Flexible scale sets ✔️ Uniform scale sets

Azure managed disks currently offer one storage redundancy option, locally-redundant storage.

Locally redundant storage for managed disks

Locally redundant storage (LRS) replicates your data three times within a single data center in the selected region. LRS protects your data against server rack and drive failures. LRS disks provide at least 99.999999999% (11 9's) of durability over a given year. To protect an LRS disk from a zonal failure like a natural disaster or other issues, take the following steps:

  • Use applications that can synchronously write data to two zones, and automatically failover to another zone during a disaster.
    • An example would be SQL Server Always On.
  • Take frequent backups of LRS disks with ZRS snapshots.
  • Enable cross-zone disaster recovery for LRS disks via Azure Site Recovery. However, cross-zone disaster recovery doesn't provide zero Recovery Point Objective (RPO).

If your workflow doesn't support application-level synchronous writes across zones, or your application must meet zero RPO, then ZRS disks would ideal.