Server storage

Server storage

Storage Spaces can create storage pools spanning many drives, from which virtual disks (not to be confused with VHD or VHDX files) can be formed. Fault tolerance of a storage space can be improved by choosing between Simple, Parity, or Mirror layout options. Mirror provides better read/write performance than parity. Individual physical disks can also be configured as hot spares. If the virtual disk is formatted as [ReFS][ReFS], it can be thinly provisioned as well. Storage Spaces also has a featured called tiered storage, which allows higher-performance devices to be reserved for more commonly used files.

Most modern SANs are based on iSCSI, and iSCSI devices are of two types: initiators that receive I/O requests from the operating system and targets that receive SCSI commands and pass them to storage devices. Windows Server 2016 includes the iSCSI Target Server role service, which allows a drive on one server to be designated as target to the initiator (installed by default) on another computer. iSNS facilitates the connection between initiator and target and sees the most use in enterprise networks. iSNS architecture consists of a server, database, clients, and the iSNS Protocol (ISNSP).

Because the collisions that are typical in Ethernet networks drastically affect the performance of SANs, their traffic is usually isolated from that of other networks. Windows Server 2016 includes DCB as an installable feature, although a server must have compatible hardware.

You can configure up to 8 total traffic classes, and a PFC for each. Multipath I/O is an installable feature that requires redundant network components and a device specific module (DSM) on every network adapter or host bust adapter that connects to the SAN.

[Storage Replica][Storage Replica] supports one-way replication between standalone servers, between clusters, and between storage devices within an asymmetric (stretch) cluster.

• Synchronous replication is possible when the replicated volumes can mirror data immediately, ensuring no data loss in case of failover
• Asynchronous replication is preferable when the replication partner is located over a WAN link

Storage Replica improves on DFS Replication, which is exclusively asynchronous and file-based, by using SMBv3 (port 445). Storage Replica requires two virtual disks, one for logs and one for data, which are the same size for each replication partner, and all the physical disks must use the same sector size.