Largest volume for Win2k NTFS

[tookawhile]

I have a hardware RAID controller with a RAID5 with a 12 x 250GB drives (DAS has 12 bays). I split the array into 2 x 1TB volume with a hotspare for each.

I'm considering changing this to 1 large 2.75GB (11 x 250GB hds) with a hotspare, this we give m 250GB of space.

The reason I split it in the first though, is that I was told that Win2k NTFS can have problems with volumes over 2TB - is this true? If I do the above will it be Ok?

 

[LWComputingMVP]

I believe the limit is 2 TB - though there's something about this "limit" that bothers me as NTFS is SUPPOSED to handle up to 16 Exabytes. I would suggest, if you have no data on the drives, that you try it and see what happens - note: you may need to use larger blocks than the standard 4K blocks to get larger drive sizes.

http://www.ntfs.com/ntfs_vs_fat.htm

See also:

http://technet2.microsoft.com/Windo...ec61-402e-96cd-986c89ef40eb1033.mspx?mfr=true

Based on this link, I would suggest creating multiple RAID volumes in the RAID controller, then spanning them in Windows.

 

[LWComputingMVP]

Why I'll say this IS confusing - referring to the article here -

http://support.microsoft.com/kb/224526

-

Although Microsoft Windows NT 4.0 can, in theory, support partitions of up to 16 exabytes in size by using the NTFS file system, the maximum size of the system partition is limited to 7.8 gigabytes (GB).

Now there's this:
(from

http://www.microsoft.com/technet/archive/community/columns/questions/peeran16.mspx?mfr=true

)

Q: How Big is "Big"?

Hello, was wondering if anybody could confirm if NT has a maximum file size. If so, what is it? I have had various explanations on this and was hoping to get a definitive response. Any help, greatly appreciated.

Reuben Dunn

A: Well Reuben, it depends on the version of Windows NT (whether it supports HPFS or not) and which file system you're talking about.

FAT and HPFS both have internal limits of 4 GB due to the fact that they use 32-bit fields to store file sizes. NTFS uses 64-bit fields for all sizes, permitting its data structures to handle volumes up to 2^64 bytes (16 exabytes or 18,446,744,073,709,551,616 bytes)—minus a little overhead. 16 exabytes is really, really huge.

This value is the theoretical limit for the NTFS file system. Practical limits having to do with the maximum allowable partition size described above limit the size of an NTFS partition to approximately 2 terabytes. Because the 32-bit fields of the partition table refer to the number of sectors in the partition, disks with larger sector sizes translate into larger permissible partition sizes. Currently Windows NT supports sector sizes up to 4 Kilobytes. With 4KB sectors, Windows NT can support a 16 terabyte partition. As new hardware or software schemes become available, NTFS will be able to handle substantially larger volume sizes.

It might be interesting to think about just how big even one exabyte is. One exabyte is 1 billion gigabytes. Let's say you need 1 exabyte of storage and decide to purchase 25 GB hard drives. In order to have one exabyte of storage, you would need almost 43,000,000 of these 25 GB drives. At about $US200 for the drives (with volume discount, tax not included), this works out to just over US$ 8.5 billion. That doesn't include the controller cards or chassis to hold these drives. I don't want to think about how long it would take to format the drives.

As long as we're straying from the subject, there's an interesting article from Michael Lesk (Division Director, Information and Intelligent Systems, National Science Foundation) titled, How Much Information is there in the World?, which can be found at

http://www.lesk.com/mlesk/ksg97/ksg.html.

The article's a couple of years old, but offers an interesting view of the near future.

I don't think I've actually helped you all that much... but hopefully it's been a good, interesting read.

 

[tookawhile]

Yep, it is confusing, I briefly looked into to it before and went for the safe option of 2 x 1TB.

There is data on there at the moment( around 900GB) but I can off load this to another server on a temporary basis if needs be, but I really don't want to use it as a test bed. I was hoping for a definitive answer so I can jut go ahead and only have one lot of data transfer to deal with.

I'll read for your post and links, see if I can get some where

 

[tookawhile]

Having read the MS link I might be Ok 'If you want to use volumes larger than 2 TB, you must use dynamic spanned, striped, or RAID-5 volumes.'

Well, I'm using RAID5 volume via the RAID controller, Win2k currently reports the 2 volumes as follows, layout as simple and type as dynamic, 1TB for each, so I guess after reconfiguring the array via the hardware RAID controler as a 2.7TB array Win2k shoudl see as 1 volume at that size, I think