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faq:0125

Q: Why is the size of my OS hard drive only 738Gb or 992Gb even though I am installing XigmaNAS on the BIGGEST drive currently made?
A:
Make sure your Motherboard is using the latest BIOS revision since some older ones do not support 3TB drives. Make sure your disk controller supports 3TB drives.

The easiest way to use a 3TB drive is as a data drive in your server (32-bit or 64-bit). Today's 3TB drives won't give you the full benefits of its total capacity unless you choose UFS/GPT (GUID Partition Table) as its partition type – it won't work properly if you choose MBR. Choosing MBR will restrict you to only 2.1TB of the drive's capacity and leave 746GB of space unusable. When you select GPT, the entire partition, all 2.72TB of usable space, will be available for formatting.

If you plan to use a 3TB boot drive, then you won't be able to use all of its capacity unless your motherboard has a UEFI BIOS and can use GPT partitions. Most operating systems still use MBR as the default partition type for boot drives. As a result 746MB of space will be unusable, and because the drive is already using MBR as the partition type, you can not convert the drive to GPT in order to format the remaining space. Save yourself the trouble and don't use a big drive for your OS.

XigmaNAS uses fdisk to create MBR partitions when you install it. In 32bit versions of FreeBSD, the fdisk utility uses a signed long integer for calculations. This limits the partition sizes it can create to about 1TB and leaves the extra space unusable. This means it is impossible for you to achieve gratification despite the huge size of your drive. For best utilization of disks, using a 64Bit version of XigmaNAS is recommended.

This limit does not apply to drives used only for data which should be formatted UFS/GPT. If you have run into this problem you should wipe your drive and re-install according to these recommendations:

  • Use a 64Bit OS if possible. The 64Bit versions will allow you to properly create partitions larger than 1TB on your OS drive.
  • If you cannot use a 64Bit OS, use your big drive for data only and re-install OS on a smaller drive.
  • XigmaNAS should not experience this issue.

References:

Basic Basic storage concept ⇒9.0.0.1
faq/0125.txt · Last modified: 2018/08/10 15:13 by zoon01