Seagate 3TB external HDD

[sureshkondaveet]

Hi,

First of all thank you for everybody.

I have a Seagate 3TB external hard drive. I's been working fine till yesterday. Yesterday I tried to format it and something went wrong and out of 2.7TB, 700 is showing as un-allocated.I am not able to format it anymore. Before I tried to format, it was showing the whole 2.7 TB but now, I am able to format only 2TB but not the rest of the 700MB.

I tried using Paragon Partition Manager personal to format it but it crashed my laptop and I had to re-install my hard drive. I haven't tried the sea tools yet but I will tonight. Let me know if you have any ideas on why I am not able to format the rest of the 700MB.

Thank you once again for everybody.

Have a great day .

 

[VirtualLarry]

You have to use GPT to partition a 3TB drive. If you format it MBR, then it is limited to 2TB. That sounds like what happened. What OS are you using to format it? XP can't do GPT.

 

[craiggloyd]

Plz state your operating system and what type of partitions you have on the external drive. As VL said, make sure it is GPT not MBR.
Screenshots would be helpful for when error messages/reports come up.

 

[Mark R]

The seagate external 3TB drives comes from the factory with a non-standard format. The problem is that MBR partition mode doesn't support drive larger than 2 TB - you need GPT. However, XP doesn't support GPT at all. Seagate has come up with a cunning workaround.

The drive is a 4k sector drive, and the 4k sectors are shown to the OS (it does not emulate 512b sectors like internal drives).

MBR partitioning is limited to 2TB because it is limited to 4 billion sectors (any sectors after 4 billion are totally invisible to MBR at cannot be accessed at all).

However, with 4k sectors, it is possible to bypass this limit because 4 billion sectors x 4k each = 16 TB, even though MBR doesn't officially support 4k sectors or drives larger than 2TB.

Nevertheless, this crazy non-standard partitioning does actually seem to work on most OSs, including XP. As a result, the manufacturers ship the drives ready formatted, so that they are XP compatible. Otherwise, there would be no way to use the full capacity in XP.

And this is the problem; the drive is showing 4k sectors to the OS, that confuses a lot of partition manager software, and may also confuse some formatting tools. The drive is also partitioned in MBR mode and most partition manager software won't allow you to create partitions larger than 2TB.

If you've got Vista or 7 - just repartition the drive in 'GPT' mode, and you'll be good to go. If you've got XP, I really don't know how to fix it.

 

[Emulex]

hitachi has a trick up their sleeves which seagate do not.