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Windows XP RAID Capacity Limit

Last response: in Storage
September 25, 2009 6:53:12 AM

I understand the 2tb MBR limit, I understand this is because of the 32bit addressing issue with 512 byte sectors. I have also read in a number of places that one can increase the sector size to increase the usable capacity of the array.
So, I have 4 tb drives configured in a RAID 5 array, which should have a capacity of 3tb. When setting it up I configured it with 4k sectors. According to "teh intarwebz" this should allow me to address up to 16tb. This box is running Windows XP and when I go into the Disk Management console it shows the drive size as 2tb. I ran a checkdisk and was able to confirm that the sector size 4096 bits. I also went into my RAID card's management console and confirmed that the array was reporting 3tb as the size.
I'm wondering if there's anything I need to do or if it's just not possible to have a 3tb array work with XP even if I use larger sectors?
a b G Storage
September 25, 2009 3:20:24 PM

I think 2TB is the max that XP will address, total sum of all disks combined. Could be wrong though.
September 26, 2009 5:23:19 AM

i dont know about xp32, but win xp64 i am definitely sure that you can have partitions bigger than 2tb. because the pc i'm using right now has xp64 and one partition with five 750gb drives in raid0... your other alternative, if it's a server box, is to simply go with linux on the box.
a b G Storage
September 26, 2009 4:37:17 PM

What does "My Computer" report?

Also, in Command Prompt, what does the DIR command report?

FYI: I'm familiar with Highpoint's RAID controllers, and
their documentation describes an option to increase
sector sizes, so as to increase the default 2TB XP limit
that exists when 512-byte sectors are used:

For example, in the User Manual for the RocketRAID 4320,
look for:

VSS (Variable Sector Size):
If the array’s capacity is over 2TB, user will be asked to select the Sector Size values
(from 512B to 4K):

Note: Variable Sector Size (VSS) for over 2TB support in 32bit LBA OS.
It changes the sector size from default 512 Bytes to 4k Bytes etc. the maximum volume
capacity up to 16TB. This option works under Windows platform only. And it CANNOT be
converted to Dynamic Disk, because 4k sector size is not a standard format.

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