Use 64K Cluster Size For NTFS On VMS Video Storage Volumes

In media server circles folks like toe recommend 64K cluster size for improved CPU efficiency when the volume is dealing mainly with large video files. Of course surveillance VMS servers are much the same. So the question is: what are your opinions on the use of 64K cluster size - waste of time to config? No real performance difference? potential unforseen consequences?


No down side for 64K clusters on most VMS setups, but the amount of benefit depends on the configuration of the storage. Some setups will see a noticeable benefit, but on most while it should be measurable, it would be in the <10% improvement range I should think. That is hard for people to really notice...

You have to format the partitions anyway, you might as well use 64K clusters instead of the 4K default... No real cost unless your VMS creates 100's of thousands of small files... (I don't know of any that do this, but someone else here might.) Statistically, you will tend to waste 1/2 a cluster for each file in the file system. So 100K files would usually waste about 3GB of space with 64K clusters, vs. about 400MB with 4K clusters for the same 100K files. Pretty small numbers for multi TB drive volumes.

Sequential performance is usually better with larger clusters, but overall it would more depend on the way your VMS handles it's storage I/O...

64KB clusters, 1MB aligned partitions and doing as much sequential I/O vs. random are the keys to good disk throughput. How you accomplish this will vary by VMS...

You could even use a SAS/SATA expander and a non-RAID JBOD for a 1:1 drive to camera ratio. 1TB 2.5 drives are <$80 each and can easily hand any single camera stream as it will be nearly all sequential I/O. A catastrophic drive failure risks only a singe camera recording. You can also go the other way with RAID6, host spares, lots of RAID cache to deal with occasional heavier drive loading and hot-swap with little-to-no down time scenarios...

Both of these work better with 64K/1MB Aligned partitions...

Just my opinions though... :-)

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