this is a quote from the sandman, from my previous thread - can anyone elaborate on this statement:


"off you are going to have issues with arrays over 2TB.
Yes highpoint blows on the high end. "


Why are 3TB or 4TB arrays an issue? we plan hooking 8 hdd in raid 5 with lsi logic card.

thank you for any input!

Windows 2K/XP have a 2TB limit on boot partitions not arrays. Thats a slip up on my part.

Windows 2K3 I believe has been patched so it can exceed 2TB partitions. If its not out yet then it should be soon.

Some controllers are stuck at 2TB LUN limitations. Make sure you read the specs carefully for the controller.

I am not aware of Vista partition size limitation.

Doesn't x64 exceed the 2T limit as well?

thx!

Volume, partition and file size limits don't rely on architecture limitations: it's only an OS limit: even an 8 bit MCU can handle 64 bit long long integers (grouping 8 consecutive bytes together), it's only a matter of OS implementation.

can you decipher that in relation to my question or that just a response to the post about 64 bit?

or, i do not understand the relevance of your answer? (or wtf does that mean (translated in noobie code (joke)))

Wrong, with ANY version of windows (on x86) there is a limit of 2TB on the boot ARRAY, this is because this is the maximum an array with MBR can support. I have a system witn Windows 2003 SP1, and a 5TB boot array, I had to scrap this in the end and create 3 smaller arrays before I could use the space.

You can use an aray with more then 2TB as a data disk, but you need to use GPT arrays, and you CAN NOT BOOT FROM THEM

http://technet2.microsoft.com/Wind [...] x?mfr=true

There is more discussion here .........................

http://www.microsoft.com/technet/p [...] 21675.mspx

I do believe that is what I said.

Anyway, they are working on a larger than 2TB bootable partition for 2003.

@maury73
Yes there are hardware limitations that can limit the array size to 2TB. It is not completely inclusive to the OS. I believe adaptec is still having issues with the 2TB limit. Most newer controller cards will specifically mention "greater than 2TB" in the specs or state the maximum by mentioning something like "32TB LUN support."

Anyway, they are working on a larger than 2TB bootable partition for 2003.


Wrong. Windows 2003 Server will NEVER be able to boot >2TB on an x86 (or x64) system. This is only possible with Windows Vista or Lonhorn server in systems with EFI compatable BIOS (aka nothing on the market at the mo)

edit - some nice supporting info... http://www.microsoft.com/whdc/devi [...] T_FAQ.mspx

Thanks you actually found the link for me. I knew I wasnt imagining things.

EFI is not necessary for greater than 2TB boot recognition. Now as soon as I find the link where they are implementing this for W2K3 I'll post it.

For the systems i asked about: we are booting from sb control with 680i chipset raid0 2x raptors. So we will be fine with a 4TB raid????


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the 4 tb is video storage - we need a single a storage due to streaming issues with multiple xbox 360's used as media exteneders

system locks and freezes when multiple drives are accessed - its a vista issue.

system must be vista comptible

Sorry, but jamesgoddard is correct. EFI is most certainly necessary for boot partitions to reside on a device with > 2^32 blocks (2TB).

The quotes you refer to are correct for large (> 2TB) arrays in general when used as data-only arrays, not boot arrays.

I recently set up a Windows Server 2003 with a 6TB iSCSI array, and learned a few things while I did it. 8)

Here is a summary:

1. The only versions of Windows that support >2 TB arrays at all are Windows XP x64, Windows Server 2003 SP1 (x86 and x64), and Windows Vista (x86 and x64).

2. The only versions of Windows that can use a >2 TB array as a boot device are Windows Vista and the not-yet-released Longhorn server. They can only do this on a system with an EFI BIOS. Any system with a standard PC BIOS cannot boot from a >2 TB array regardless of operating system.

3. To support an array >2 TB, the device must be converted to a GPT disk in Windows Disk Management.

4. To support a device >2 TB, the controller must support some type of extended addressing mechanism (48-bit LBA for IDE/SATA devices, 64-bit LBA / 16-byte CDB for SCSI API-compatible controllers). If the controller doesn't support this, the maximum array size it can support is 2TB.

5. Some controllers will assist you in hooking up a large array to an operating system that doesn't support it (such as Windows XP) by using LUN carving. Using this, a large array appears to the computer as multiple 2TB arrays. Each 2TB virtual array can then be formatted as a standard MBR disk. Of course, not all of your space will be on one volume.

6. The FAT32 file system is not supported on arrays >2TB. Volumes >2TB must be NTFS. NTFS will support up to a 256TB array in its current implementation.

7. It is recommended that >2TB arrays be basic disks unless absolutely necessary to make them dynamic disks. Dynamic disks are only supported on devices that are direct connected or connected on a SAN through a Fibre Channel card or iSCSI hardware card. Dynamic disks are not supported using the Microsoft iSCSI software initiator.

8. Some RAID controllers and SAN units have a hack that is supposed to let them get around the 2TB limit on operating systems that don't support it. To implement it, they increase the sector size from the standard 512 bytes up to as large as 4096 bytes. Using this, they purport to be able to support up to a 16 TB array as an MBR disk. Do not use this mechanism under Windows. Windows specifically does not support any device with a sector size other than 512 bytes. Under Linux OS's, this should work OK.

wow - good stuff
thank you!

To anybody thinking about Volums >2TB on clustered Windows Servers follwo this link:

http://technet2.microsoft.com/Wind [...] x?mfr=true

Note what they wrote:

• You cannot use the GPT partitioning style on removable media, or on cluster disks that are connected to shared SCSI or Fibre Channel buses used by the Cluster service.

So, if you are running clusterd (failover cluster) Servers, you will be allways limited to max. partition size 2TB.

Not really related to your discussion but I searched Wiki to understand EFI and at the bottom I saw this:

SWEET :!:

Edit: link
Extensible Firmware Interface - Wikipedia
http://en.wikipedia.org/wiki/Exten [...] _Interface

Why would you want a boot partition larger than 2 TB? Why would you want one even close to that size?

Can I quote you on that in 10 years time?

we have had problems in past with multiple drives and multiple media extenders. it appears if the movies are stored on single drive or in this case a single large partition of 8 x 500gb drives then we have less problems with lag for lack of a better word - when watching 3 different movies using xbox 360's as a media extender on 3 different tv's it seem to work better with a single drive.

i would use a seperate raid 1 for your OS and use a raid 5 for your data, 8 drives raid 0 for 4TB is just asking for failure and losing all your data, raid 5 could at least handle single drive failure, but still wont replace a backup...speaking of which what are you using to back that up?