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Content Owner: Roman Macek | ||||
Summary
CSV Cache; Write-Back Cache - Storage Spaces Direct Cache
Details
In WS 2012 R2 there are two main features to provide perfromance improvements through caching
1. CSV Cache:
Windows Server 2012 introduced the CSV cache to provide (READ) caching on the block level by allocating system memory (RAM) as cache. This can significantly improve Hyper-V read performance (e.g. VDI boot storms).
New in WS 20012 R2:
- In Windows Server 2012, you could allocate only 20% of the total physical RAM to the CSV cache. You can now allocate up to 80%.
- In Windows Server 2012, the CSV cache was disabled by default. In Windows Server 2012 R2, it is enabled by default.
2. Storage Spaces Write- Back Caching:
Storage Spaces can use existing SSDs in the storage pool to create a write-back cache that buffers small random writes to SSDs before later writing them to HDDs.
- write-back cache is transparent to administrators and users and is created on all new virtual disks as long as there is a sufficient number of SSDs in the storage pool (Simple spaces: one SSD, Two-way mirror spaces and single-parity spaces: two SSDs, three-way mirror spaces and dual parity spaces: three SSDs)
- write-back cache works with all types of storage spaces, including storage spaces with storage tiers
- newly created storage spaces automatically use a 1 GB write-back cache (as long as the storage pool contains enough disks with MediaType set to SSD or Usage set to Journal)
3 - The Storage Spaces Direct provides a highly available cache system based on the fastest storage devices. In production it is recommended to deploy two storage devices. Storage Spaces Direct requires Windows Server 2016 Datacenter edition.
1. CSV Cache:
Windows Server 2012 introduced the CSV cache to provide (READ) caching on the block level by allocating system memory (RAM) as cache. This can significantly improve Hyper-V read performance (e.g. VDI boot storms).
New in WS 20012 R2:
- In Windows Server 2012, you could allocate only 20% of the total physical RAM to the CSV cache. You can now allocate up to 80%.
- In Windows Server 2012, the CSV cache was disabled by default. In Windows Server 2012 R2, it is enabled by default.
2. Storage Spaces Write- Back Caching:
Storage Spaces can use existing SSDs in the storage pool to create a write-back cache that buffers small random writes to SSDs before later writing them to HDDs.
- write-back cache is transparent to administrators and users and is created on all new virtual disks as long as there is a sufficient number of SSDs in the storage pool (Simple spaces: one SSD, Two-way mirror spaces and single-parity spaces: two SSDs, three-way mirror spaces and dual parity spaces: three SSDs)
- write-back cache works with all types of storage spaces, including storage spaces with storage tiers
- newly created storage spaces automatically use a 1 GB write-back cache (as long as the storage pool contains enough disks with MediaType set to SSD or Usage set to Journal)
3 - The Storage Spaces Direct provides a highly available cache system based on the fastest storage devices. In production it is recommended to deploy two storage devices. Storage Spaces Direct requires Windows Server 2016 Datacenter edition.
