Getting ready to deploy a 3TB to be used as shared backup and file storage for Windows 7/10 and Linux. I know I need to set it to GPT partition table, but what I'd the best cluster/allocation unit size? 4k is default but I know 1k and 2k would support this size volume… Is there any reason not to use a smaller allocation unit size to make more efficient use of disk space with smaller files or is better to stick the default 4k size for some reason?
3TB NTFS Volume Allocation Unit Size
allocation-unithard driventfspartitioning
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You should be able to do this from a command line using the newfs_msdos
command. For example:
#> newfs_msdos -F 32 -V somevolumename /dev/youdiskdevice
The command takes many arguments that you may want to explore.. -c
cluster-size for example.
I am sure you could google around for newfs_msdos for some usage examples and also man newfs_msdos
Hope this helps!
Many Western Digital external USB drives over 2 TB (including at least some My Book, My Book Essential, Elements, and Easystore drives) can be configured for either 512 byte logical sectors or 4096 byte logical sectors using the WD Quick Formatter tool. When configured for 4096 byte logical sectors, the USB-to-SATA bridge in the enclosure does a translation between 512 byte logical sectors at the SATA interface to the internal drive and 4096 byte logical sectors at the USB interface to the host computer.
With 512 byte logical sectors, an MBR partition table could only use up to 2 TB of a drive. That's because MBR table entries are 32 bits with a max of 2^32 or 4,294,967,296 sectors. 2^32 sectors x 512 bytes/sector is 2 TB. With 4096 byte logical sectors, an MBR partition cable can use up to 16 TB of a drive. (2^32 sectors x 4096 bytes/sector is 16 TB) Windows XP only supports MBR partition tables, and so 4096 byte logical sectors are the only way to use all of the space on a drive over 2 TB in Windows XP. The newer GPT partition table format supported in Windows Vista and later does not have the 32-bit limitation, and can support disks larger than 2 TB regardless of the sector size.
The WD Quick Formatter tool (version 2.0.0.65 available for download as of this writing) can enable or disable the sector size translation. This version of the tool does not work correctly under Windows XP, so I recommend running the tool in Windows 7 or later. When run in Windows 7, or in later version of Windows but with Windows 7 compatibility mode, the tool will present two configuration options on the "Format your WD external drive" screen:
- XP Compatible: This option configures the drive for 4096 byte logical sectors, and creates an MBR partition table.
- Most Compatible (Vista or later required): This option configures the drive for 512 byte logical sectors, and creates a GPT partition table.
Both options also create a single partition filling the entire drive, and quick format it in NTFS.
If you run the tool in Windows 8 or later without putting it in Windows 7 compatibility mode, the tool will not present a compatibility option on the formatting screen and it will format in the "most compatible" mode (512 byte logical sectors).
WD Quick Formatter 2.0.0.65 doesn't work correctly in Windows XP: it successfully configures 4096 byte logical sectors, but fails to format correctly. Another tool can subsequently be used to partition and format the drive.
WD Quick Formatter 1.2.0.10 works correctly in Windows XP, but is not available for download from Western Digital anymore.
When the target drive is configured for the same logical sector size as the source, you can copy to it using dd and the copy will work without any need to alter the partition table.
I can confirm that these Western Digital external USB drives can be configured for XP compatibility:
Easystore 14 TB (WDBCKA0140HBK)
Easystore 12 TB (WDBCKA0120HBK)
Easystore 8 TB (WDBCKA0080HBK)
My Book Essential 1140, 3 TB (WDBACW0030HBK)
Elements 1021, 3 TB (WDBAAU0030HBK)
Best Answer
@acejavelin!
It really depends on the files you plan to store on that 3 TB HDD. However, it's highly recommended to use the default 4K for any NTFS hard drive that is smaller than 16 TB.
Just like @whs mentioned, smaller allocation unit size would make sense only if you're keeping small doc files (for example) This way a very small portion of the HDD space will be wasted. If you plan to back up massive data like HD videos, photos, movies, etc., then even bigger than the 4K default AUS would be better.
I'd suggest you to read through this article about the Allocation Unit Size Differences
Good luck. Hope this helps. :)