Hello,
historically, there were 4 standard cluster sizes on NTFS volumes:
- 0,5 kB on volumes smaller than 0,5 GB (allows up to 2 TB)
- 1 kB on volumes larger than 0,5 GB (allows up to 4 TB)
- 2 kB on volumes larger than 1 GB (allows up to 8 TB)
- 4 kB on volumes larger than 2 GB (allows up to 16 TB)
Currently, as far as i know it, these rules are no longer used and all volumes are formatted with 4 kB cluster sizes. However on volumes that are larger than 16 TB, i suppose that during initial formatting, the standard cluster size is set to greater values.
Problems arise (and i have seen many discussion about this here on the forums and on the web) when volumes are initially created with a size smaller than 16 TB and then enlarged beyond this limit. Windows formats them with a cluster size of 4 KB which is not sufficient if the volumes grow larger. I just had a case where this happened: 6 x 3TB in a hardware RAID5 was extended to 8 x 3 TB and the customer was not able to enlarge the volume to cover up the new space.
Now on to my proposal: I would like to see some more standard cluster size recommendations that are *automatically* employed by Windows upon formatting. Having the ever growing HDD capacity in mind, even home users may have the above problem in few years when they use software- or hardware assisted RAID. An example for the standard cluster sizes could be:
- 8 kB on volumes larger than 1 TB
- 16 kB on volumes larger than 2 TB
- 32 kB on volumes larger than 4 TB
- 64 kB on volumes larger than 8 TB
This would make up for a reserve of a 32-times increase in capacity compared to the initially formatted capacity.
Please let me know if i'm completely wrong.
Regards, Christian