What is new in VMFS5

VMFS 5 enhancements are as follows

- Unified block size: VMFS 5 offers a unified block size of 1 MB compared to the multiple block sizes in VMFS 3. The size of largest single VMDK file is not limited by this block size. The maximum vmdk size possible is 2 TB - 512
- Smaller sub block:  The sub-block size in VMFS 5 is 8 KB compared to the 64 KB size of VMFS 3. This means that smaller files with size less than 8 KB( but greater than 1 KB) will consume only 8 KB disk space in place of 64 KB. This reduces the amount of disk space hogged by smaller files, and thereby better utilization of disk space
- Large single extend volumes:  In VMFS 3 the largest single extend possible was 2 TB. In VMFS 5, this has been increased to approx 60 TB
- Small file support :  For files smaller than 1 KB, a file descriptor location in the storage metadata is used rather than file blocks. When they grow above 1 KB, file blocks are used. This again reduces the disk space utilized by small files
-Increased file count: VMFS 5 supports more than 1 lakh files, where as VMFS 3 could support only approx 30 thousand files
-Atomic test and set(ATS) enhancement:  ATS technology which is part of VAAI(vSphere Storage API for Array Integration), is used for file locking which considerably increases the file locking performance of VMFS 5 over its predecessor


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