#Disk aid versus drive doctor windows

Azure Backup is available through Azure Disk Backup.Azure Site Recovery support isn't yet available.When using proximity placement groups (PPG), all virtual machines sharing a disk must be part of the same PPG.

When using Availability sets or Virtual Machine Scale Sets with Azure shared disks, storage fault domain alignment with virtual machine fault domain isn't enforced for the shared data disk.Disk bursting isn't available for premium SSD disks with maxShares>1.Host caching isn't available for premium SSD disks with maxShares>1.Can only be enabled on data disks, not OS disks.When sharing Premium SSD v2 disks, they have the following additional limitation: For these limitations, see Premium SSD v2 limitations. Premium SSD v2 managed disks have their own separate list of limitations, unrelated to shared disks. Can't be shared across availability zones.

#Disk aid versus drive doctor windows

Only basic disks can be used with some versions of Windows Server Failover Cluster, for details see Failover clustering hardware requirements and storage options.When sharing ultra disks, they have the following additional limitations: For ultra disk limitations, refer to Using Azure ultra disks. Ultra disks have their own separate list of limitations, unrelated to shared disks. Host caching isn't supported for shared disks.Įach managed disk that has shared disks enabled are also subject to the following limitations, organized by disk type: Ultra disks A shared disk can't be expanded without either deallocating the VMs or detaching the disk.

Shared disks can be attached to individual Virtual Machine Scale Sets but can't be defined in the Virtual Machine Scale Set models or automatically deployed. Currently only ultra disks, premium SSD v2 managed disks, premium SSD managed disks, and standard SSDs can enable shared disks. Limitations General limitationsĮnabling shared disks is only available to a subset of disk types. You need to use a cluster manager, like Windows Server Failover Cluster (WSFC), or Pacemaker, that handles cluster node communication and write locking. Shared managed disks don't natively offer a fully managed file system that can be accessed using SMB/NFS. These LUNs look like direct-attached-storage (DAS) or a local drive to the VM. LUNs are then presented to an initiator (VM) from a target (disk). Shared managed disks offer shared block storage that can be accessed from multiple VMs, these are exposed as logical unit numbers (LUNs). Enabling SCSI PR on a managed disk allows you to migrate these applications to Azure as-is. SCSI PR is an industry standard used by applications running on Storage Area Network (SAN) on-premises. VMs in the cluster can read or write to their attached disk based on the reservation chosen by the clustered application using SCSI Persistent Reservations (SCSI PR). Attaching a managed disk to multiple VMs allows you to either deploy new or migrate existing clustered applications to Azure. Applies to: ✔️ Linux VMs ✔️ Windows VMs ✔️ Flexible scale sets ✔️ Uniform scale setsĪzure shared disks is a feature for Azure managed disks that allow you to attach a managed disk to multiple virtual machines (VMs) simultaneously.