Some NTFS recommendations
Technorati Tags: NTFS,Windows Server
Recommended disk cluster size for NTFS
During windows installation windows formats the partition based on the geometry of the disk, following table shows what is the recommended cluster size based on the size.
CLUSTER SIZE |
MAX NTFS VOLUME SIZE (bytes RAW) |
| 512 | 2,199,023,255,552 (2TB) |
| 1024 | 4,398,046,511,104 (4TB) |
| 2048 | 8,796,093,022,208 (8TB) |
| 4096 | 17,592,186,044,416 (17TB) |
| 8192 | 35,184,372,088,832 (35TB) |
| 16384 | 70,368,744,177,664 (70TB) |
| 32768 | 140,737,488,355,328 (140TB) |
| 65536 | 281,474,976,710,656 (281TB) |
Once a partition is formatted with a cluster size, the only way to change the cluster size is to format the disk again and specifying the cluster size using format command or from GUI.
NTFS Optimization
If you investigate your storage needs, you can tune some of global NTFS parameters to achieve significant increase of disk performance. Other techniques like disk defrag could help you either.
Define Cluster Size Properly
Cluster is an allocation unit. If you create file lets say 1 byte in size, at least one cluster should be allocated on FAT file system.
On NTFS if file is small enough, it can be stored in MFT record itself without using additional clusters. When file grows beyond the cluster boundary, another cluster is allocated. It means that the bigger the cluster size, the more disk space is wasted; however, the performance is better.
The following table shows the default values that Windows uses for NTFS formatting:
Drive size (logical volume) |
Cluster size |
Sectors |
512 MB or less |
512 bytes |
1 |
513 MB - 1,024 MB (1 GB) |
1,024 bytes (1 KB) |
2 |
1,025 MB - 2,048 MB (2 GB) |
2,048 bytes (2 KB) |
4 |
2,049 MB and larger |
4,096 bytes (4 KB) |
8 |
However, when you format the partition manually, you can specify cluster size 512 bytes, 1 KB, 2 KB, 4 KB, 8 KB, 16 KB, 32 KB, 64 KB in the format dialog box or as a parameter to the command line FORMAT utility.
We know that if we format the partition manually, you can specify cluster size 512 bytes, 1 KB, 2 KB, 4 KB, 8 KB, 16 KB, 32 KB, 64 KB in the format dialog box or as a parameter to the command line FORMAT utility.
So to proceed with the best practices we must determine average file size and format the partition accordingly.
On Volumes, having cluster size more than 4 KB compression is not supported
Some Microsoft white papers on disk subsystem performance and SAN recommendations:
https://www.microsoft.com/windowsserversystem/storage/indextecharticle.mspx
https://www.microsoft.com/windowsserver2003/techinfo/overview/fileconsol.mspx
https://download.microsoft.com/download/5/b/5/5b5bec17-ea71-4653-9539-204a672f11cf/LocFileSys.doc”
https://www.microsoft.com/whdc/device/storage/subsys_perf.mspx