3tb esternal USB hard drives under 4.2.17

[BotanyBay]

Having some difficulty seeing the full 3tb on an external USB hard drive. I just updated the Readynas Pro Buisness from 4.2.5 -> 4.2.17 inorder to use 3TB drives as backup media.

I had expected to see ext4 as an option for formatting these drives in the USB volume drop down and I do not. Additionally the drives are seen as 2047GB rather than some number closer to 3000GB.

I am currently using bare Hitachi drives (HDS723030ALA640) from the HCL so that I can install them in the Readynas at some future date when even bigger drives are available for backup media.

I am using a Bytecc SATA Drive Mate to convert from SATA -> USB 2.0 and then into the Readynas.

The drives function correctly, I have two of them formatted as 2047GB drives and have a complete backup of the readynas (made just before the update).

Is this an issue with the SATA -> USB converter not being up to the task or do I need to perform a full reset of the hardware (i.e. wipe the readynas) to get this functionality?

If it is a problem with this SATA -> USB converter is there a unit which would be expected to work.

I currently have 3 seagate 2TB drives and 3 Seagate 750GB drives installed and everything is working well. Other than not being able to see the full capability of these drives when used as external USB backup media.

Thank you for your help.

[mdgm]

Are the USB drives formatted to use GPT? Have you tried connecting the drives to a PC and formatting the drives using that PC?

[BotanyBay]

The drive I have connected at the moment has never been formatted, it is brand new.

Are you saying that the ReadyNAS cannot format an external drive with GPT to allow the larger drive size but that once the drive is formatted on some other device it can read and write the drive correctly?

Thank you for the help. Definitely an interesting issue.

[mdgm]

It's something perhaps worth trying. I'm not sure what state the GPT support external drives is in (I don't have any 3TB drives to test with). If a NetGear dev takes a look at this thread hopefully they'll know the answer.

[BotanyBay]

I will keep the list updated on what I find. Luckily the drives are useable at the 2TB level until I can make this work as backup media. Eventually they will end up as part of the system when even bigger drives are available as backup media.

[davidarky]

I am having the same issue. I recently purchased a Newer Tech Voyager Q dock that could specifically read the 3TB Hitachi drives.
I thought that my issue was that the older Newer Tech dock could not "see" the 3TB drive...
But no when attempting to format the drive using the ext3 option, the formatted size never exceeds 750 gb...
I have attempted this two or three times, with the 4.2.17 update installed.
Any help would be appreciated. I don't have a PC around to format the drive as previously suggested
David
+++++++++++++++++
ReadyNas Ultra6, NV+

[BotanyBay]

I am having the same issue. I recently purchased a Newer Tech Voyager Q dock that could specifically read the 3TB Hitachi drives.
I thought that my issue was that the older Newer Tech dock could not "see" the 3TB drive...
But no when attempting to format the drive using the ext3 option, the formatted size never exceeds 750 gb...
I have attempted this two or three times, with the 4.2.17 update installed.
Any help would be appreciated. I don't have a PC around to format the drive as previously suggested
David
+++++++++++++++++
ReadyNas Ultra6, NV+

I am not having any trouble getting the 3tb drive seen as a ~2tb drive using various controllers. I am not seeing the whole drive. I have definitely seen that a PC with the drive hooked up as USB sees the drive the same way as the ReadyNAS. So I don't have to keep trying with the ReadyNAS until I see the PC has an ability to see the drive correctly.

What I have not tried is hooking the drive directly to a SATA controller and then formatting the drive. That is interesting but I would think it might just make the drive unreadable via the USB connection.

I am sure this will get worked around, worse comes to worse I put the 3Tbyte drives into the Readynas and use the existing 2TB drives as the backup media.

David

[BotanyBay]

I have found that there are at least three different behaviours of the USB controllers out there when dealing with 3TB drives.

type1) Sees the drive as 2794GB and works correctly: NexStar CB-SATAU3

type2) Sees the drive as 2046GB but otherwise works correctly: BYTECC BT-370

type3) Sees the drive as ~768GB but otherwise works correctly: VanTec SATA/IDE to USB2 adapter

Note that the safety of the data on the drive seems to require using the same varient of controller with the drive. I have experienced data loss hooking up the drive to a different adapter which behaves differently without performing a format or any other activity

I have gotten the type 1 and type 2 controllers to successfully backup data to an Hitachi Deskstar 7200RPM drive with 64MB of cache (happens to be on the HCL list as I will use it in the ReadyNAS eventually)

Be careful out there but with care it does work correctly.

David

[sphardy]

No where in this thread do I see verification that the 3TB drives have been partitioned using GPT as questioned by @mdgm. It is important to ensure the correct partition type is used as the ReadyNAS will not re-partition an already partitioned USB drive, only reformat it. (Partitioning of new completely blank drives is of course supported)

The 2 major partition types are MBR and GPT. MBR is limited disks to 2TB capacities - which is why Netgear added GPT support - and the symptoms described are typical of MBR partitioned drives

This does not rule out USB controller limitations, but it should at least be investigated before making any conclusions. How to verify the partition format will depend on your hosts' OS, but is typically reported by the OS disk utilities

[BotanyBay]

No where in this thread do I see verification that the 3TB drives have been partitioned using GPT as questioned by @mdgm. It is important to ensure the correct partition type is used as the ReadyNAS will not re-partition an already partitioned USB drive, only reformat it. (Partitioning of new completely blank drives is of course supported)

The 2 major partition types are MBR and GPT. MBR is limited disks to 2TB capacities - which is why Netgear added GPT support - and the symptoms described are typical of MBR partitioned drives

This does not rule out USB controller limitations, but it should at least be investigated before making any conclusions. How to verify the partition format will depend on your hosts' OS, but is typically reported by the OS disk utilities

Ah yes, I knew I was forgetting to mention something important. Under windows the only controller that could see the whole disk also showed that the MBR was there and provided the option of creating a 2tb partition and leave the remaining 0.75TB unused. However, on a Windows 7 box I was able to click on the left side of "disk manager" and one of the options was convert disk to GPT. Prior to that point while the readynas would report 27xx GB of disk space when formatted to ext3 it would provide a 2048GB partition. Once the conversion from MBR to GPT took place then when formatted I got a 2.7TB disk.

I went back to the old controllers as a test and found the same issues as before so looks like a mixture of GPT vs MBR and controller limitations.

[sphardy]

So the net result of this thread is "3TB external USB hard drives under 4.2.17 = works fine, but requires a SATA-to-USB converter also certified as compatible with 3TB drives if you plan on using a bare HDD"?

[BotanyBay]

The only question is if you have to be using 4.2.19 or 4.2.17. I did not manage to obtain a compatable sata to USB converter until after having moved to 4.2.19 but I suspect that either would work.

[davidarky]

Could anyone suggest a more suitable drive enclosure for the 3TB drive, since the Newer Tech Voyager Q dock does not recognize or support this drive as it appears when connect to the ReadyNAS ?
Thanks,
David

[TeknoJnky]

As mentioned, over 2tb support requires GPT partitions.

Unfortunately xp does not support GPT partitions, you must use vista/win7, or linux or mac to partition for GPT.

@ davidarky, if you have an NV+, the nv+/duo does NOT support GPT partitions, so the 3tb+ drives will NOT work.

If you want to backup using the 3tb drive, you will have to attach it to a PC/MAC that is compatible with 3tb drives, then backup over the network to the PC with the usb drive attached.