For any disk presented to Windows Server, it must be formatted according to SQL Server and Pure best practices per the article “Best Practices: Microsoft SQL Server”. The best practice is to use an allocation unit size to 64KB, which reduces both VM and database fragmentation and better lines up with the manner in which applications utilize the underlying disk. The default OS-level block size is 4KB and can cause performance issues shown in
The volume can be formatted as either GUID Partition Table, or GPT, or Master Boot Record, or MBR, partition structure. This partition structure is the method the OS uses to store data to the drive. It includes information on where the logical beginning and end of the partition is, so the OS knows the sector boundaries of the drive itself, as well as which is bootable.
GPT is the recommended option and exceeds the limitation of 2TB and four partitions. GPT can allocate volumes up to the OS maximum. It also contains checksum values to validate the data is intact and not corrupt.
Windows Server supports two different file systems: New Technology File System (NTFS) and Resilient File System (ReFS). While FlashArray supports both file systems, NTFS is recommended. See “Windows File Systems for FlashArray” in the Microsoft Platform Guide for more information.
When formatting, consider using a large NTFS file record segment (FRS), or a record segment size of 4096 bytes instead of the default 1024. The NTFS metadata blocks are mapped and maintained by the guest OS, so less objects to manage result in a faster I/O access pattern for large drives.
Issue the following command for each drive listed above used for Hyper-V VMs, databases, and backup files. Change the volume path parameter to the appropriate drive letter or mount point. The following commands assume a 64KB NTFS allocation unit size.
format <VolumePath> /A:64K /L /Q
This command can also be executed in PowerShell as follows:
Format-Volume -FileSystem NTFS -NewFileSystemLabel <LabelName>
-AllocationUnitSize 65536 -UseLargeFRS -DriveLetter <VolumePath>