Whahuh? 2TB per array? :confused:

I think it may be related to the size of a block on the HDD (512 bytes) multiplied with the width of the "index" that the controller holds, which could be 32-bits. So 2^32 * 512bytes =~2TiB.
 
2TB is the maximum basic volume size for a WinXP disk. Beyond that you have to switch to dynamic disks (here be monsters).
 
drizzt81 said:
I think it may be related to the size of a block on the HDD (512 bytes) multiplied with the width of the "index" that the controller holds, which could be 32-bits. So 2^32 * 512bytes =~2TiB.
Click to expand...

Believe thats the primary reason, since most controllers now are advertising 64-bit LBA for greater then 2TB support.
 
Zamboni said:
2TB is the maximum basic volume size for a WinXP disk. Beyond that you have to switch to dynamic disks (here be monsters).
Click to expand...

or multiple basic volumes per array.

I guess this means my 10TiB single volume fileserver is out of the question for now :D
 
ryan_975 said:
or multiple basic volumes per array.

I guess this means my 10TiB single volume fileserver is out of the question for now :D
Click to expand...
not really, but you get to be a guinea pigs for the reliability :D
 
drizzt81 said:
not really, but you get to be a guinea pigs for the reliability :D
Click to expand...

Ah well, seeing that I don't know of any RAID controllers that have at leat 13 (RAID0 750GB) or 14(RAID5 750GB) channels, I won't be a guinea pig anytime soon. :p
 
With SATA you could do it.
24x 750GB in R5 = 15.6TB Formatted.
http://www.areca.com.tw/products/html/pcietosata1280.htm

There are plenty of 16-port SATA RAID controllers. Hell, you could do R6 and still break 10TB capacity(9.5TB formatted).


Oh yeah, considering I have a 2.03TB array on my highpoint 2320, I don't think it is an issue. The problem will be the OS, not the controller. Linux will work fine as long as you aren't using fdisk. I run XFS directly on the block device, no need for partitions.

See?
4tb.jpg

Code: 
(09:20:30)[dew@Terabyte ~]$ df -B 1G
Filesystem           1G-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                            71         7        60  10% /
/dev/sda1                    1         1         1  11% /boot
tmpfs                        1         0         1   0% /dev/shm
/dev/sdb                  2086       921      1165  45% /mnt/terabyte
//10.10.10.20/Terabyte2
                          2086      1509       578  73% /mnt/terabyte2
//10.10.10.20/Upload        72         8        65  11% /mnt/smb
 
yeah those areca cards have some 20+ port models.

this one (ARC-1280) has 24 ports but costs over $1,500. The rocket raids are ok because you can use the cross-link to do multiple card single arrays. (you can add drives if you fill up one card and then get another card and then add drives to that card, conect the new card with the old one and then run online capacity expansion to expand your array).

You'd then have to modify the current partition to expand it using partiton magic. Unfortunatley for OS X I haven't found a way to expand the existing partiton OR format the new space without completely erasing the entire volume.

Only problem is that in OS X the OCE (online capacity expansion) is a little tricky. I lost all my data trying the OCE because there's no utility I know of for OS X that will do partiton expansion (I've tried them all and have contacted their R/D departments).

I think you can modify the file tree in terminal I've heard reported.

Didn't m$ fix the 2 TB limit?

I run my raid-5 on OS X which solved the 2 TB limit some three years ago if I remember.

I have a R5 ~1TiB on a rr2220.

It's rock solid but if I ever wanted to epand the array I'd instead have to setup a new volume b/c array expansion in OS X doesn't seem to work when it comes to expanding the logical partiton with disk utility or 3rd party utils.

best of luck.
 
piako said:
yeah those areca cards have some 20+ port models.

this one (ARC-1280) has 24 ports but costs over $1,500. The rocket raids are ok because you can use the cross-link to do multiple card single arrays. (you can add drives if you fill up one card and then get another card and then add drives to that card, conect the new card with the old one and then run online capacity expansion to expand your array).

You'd then have to modify the current partition to expand it using partiton magic. Unfortunatley for OS X I haven't found a way to expand the existing partiton OR format the new space without completely erasing the entire volume.

Only problem is that in OS X the OCE (online capacity expansion) is a little tricky. I lost all my data trying the OCE because there's no utility I know of for OS X that will do partiton expansion (I've tried them all and have contacted their R/D departments).

I think you can modify the file tree in terminal I've heard reported.

Didn't m$ fix the 2 TB limit?

I run my raid-5 on OS X which solved the 2 TB limit some three years ago if I remember.

I have a R5 ~1TiB on a rr2220.

It's rock solid but if I ever wanted to epand the array I'd instead have to setup a new volume b/c array expansion in OS X doesn't seem to work when it comes to expanding the logical partiton with disk utility or 3rd party utils.

best of luck.
Click to expand...

I believe NTFS 5 is limited to 2TB volumes. I know some RAID cards allow for greater than 2TB volumes, although, I do not run RAID so I do not know for sure.
 
The 2TB limitation as noted is a 32bit (31bit really, its a signed int for some reason) limitation for standard partitions. This is the limitation for most BIOS arrays - meaning that very few (if any) BIOS's support a larger partition size (Giant Partition Tables). Assuming that the operating system supports a larger size, you can use GPT's to overcome it. In Linux you can add what is called "Large Block Device Support" which will redo everything to something like 48 or 64bits, drastically increasing your maximum block size. As noted though, you can't boot off this, but its handy for secondary arrays.

My new fileserver has 2.1tb using 8x320gb in raid5 using the Linux solution I mentioned above. I don't even bother with GPT's I just let the filesystem (xfs) reside on the entire array.

Code: 
llama ~ # fdisk -l /dev/md0

Disk /dev/md0: 0 MB, 0 bytes
2 heads, 4 sectors/track, 0 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md0 doesn't contain a valid partition table
llama ~ # df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda3              19G  3.1G   15G  18% /
udev                  250M  164K  250M   1% /dev
shm                   250M     0  250M   0% /dev/shm
/dev/md/0             2.1T   13G  2.1T   1% /mnt/raid
 
Dew said:
With SATA you could do it.
24x 750GB in R5 = 15.6TB Formatted.
http://www.areca.com.tw/products/html/pcietosata1280.htm

There are plenty of 16-port SATA RAID controllers. Hell, you could do R6 and still break 10TB capacity(9.5TB formatted).


Oh yeah, considering I have a 2.03TB array on my highpoint 2320, I don't think it is an issue. The problem will be the OS, not the controller. Linux will work fine as long as you aren't using fdisk. I run XFS directly on the block device, no need for partitions.

See?
http://pages.woods.us/4tb.jpg
Code: 
(09:20:30)[dew@Terabyte ~]$ df -B 1G
Filesystem           1G-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                            71         7        60  10% /
/dev/sda1                    1         1         1  11% /boot
tmpfs                        1         0         1   0% /dev/shm
/dev/sdb                  2086       921      1165  45% /mnt/terabyte
//10.10.10.20/Terabyte2
                          2086      1509       578  73% /mnt/terabyte2
//10.10.10.20/Upload        72         8        65  11% /mnt/smb
Click to expand...

Like I said, I didn't know of any. But I'd never been inclined ot look for one. Now I know, and maybe I can get the 10TB array after all :p. Now I just need to decide on which bank to rob....
 
Dew said:
With SATA you could do it.
24x 750GB in R5 = 15.6TB Formatted.
http://www.areca.com.tw/products/html/pcietosata1280.htm

There are plenty of 16-port SATA RAID controllers. Hell, you could do R6 and still break 10TB capacity(9.5TB formatted).


Oh yeah, considering I have a 2.03TB array on my highpoint 2320, I don't think it is an issue. The problem will be the OS, not the controller. Linux will work fine as long as you aren't using fdisk. I run XFS directly on the block device, no need for partitions.

See?
4tb.jpg

Code: 
(09:20:30)[dew@Terabyte ~]$ df -B 1G
Filesystem           1G-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                            71         7        60  10% /
/dev/sda1                    1         1         1  11% /boot
tmpfs                        1         0         1   0% /dev/shm
/dev/sdb                  2086       921      1165  45% /mnt/terabyte
//10.10.10.20/Terabyte2
                          2086      1509       578  73% /mnt/terabyte2
//10.10.10.20/Upload        72         8        65  11% /mnt/smb
Click to expand...

But what would be the point of having a 10TB array if you couldn't access it remotely with windows?

I'm a bit confused, so linux has a utility that can override a drive controller's limitation and allow it to go to 64bit from being a 32bit? What is specifically '32bit' cause I know controllers these days support 48bit Logical Block Accessing

Zamboni said:
2TB is the maximum basic volume size for a WinXP disk. Beyond that you have to switch to dynamic disks (here be monsters).
Click to expand...

Here be monsters? How do you mean? Are you talking about the array's capacity? Whats your issue with dynamic disks, unless of course you're talking about the issue with linux and dynamic disks?
 
http://docs.info.apple.com/article.html?artnum=25557

Mac OS X: Mac OS Extended Format volume and file limits
This document outlines the limits for files and volumes on disks that use the Mac OS Extended format (HFS Plus) in Mac OS X, including journaled HFS+ volumes.

Volume and file limits in Mac OS X
Maximum number of volumes No limit
Maximum volume size and file size 2, 8, or 16 terabytes
(1, 2)
Maximum number of files (or files and folders) in a folder up to 2.1 billion (3)

Notes


For Mac OS X 10.3, 10.4 or later, the maximum volume size is 16 TB (terabytes). For Mac OS X 10.2 and Mac OS X 10.2 Server, the maximum volume size is 8 TB. For earlier versions of Mac OS X, the maximum is 2 TB.


The theoretical maximum file size for a Mac OS Extended file system is millions of terabytes. In practice, the maximum file size is equivalent to the maximum volume size, except for a small amount of disk space reserved for file system information.


Specifically, 2^31, or 2,147,483,648. However, the actual number of files that can be stored on a Mac OS Extended (HFS Plus) or journaled HFS+ volume depends on the volume's size and the size of the files. For example, a 160 GB Mac OS Extended volume with the default block size of 4 KB has 40 million available blocks. This volume could store up to 40 million very small files, but not 2 billion. A bigger disk with the same default block size could hold proportionately more files.
Click to expand...

sorry man I only know about OS X raid. I know nothing about Linux and XP raidish stuff.

I think that 2 TB or 2 GB is the maximum network transfer size of something.

If you check out the forums at infrant.com you'll see some people talking about that.
 
protias said:
I believe NTFS 5 is limited to 2TB volumes. I know some RAID cards allow for greater than 2TB volumes, although, I do not run RAID so I do not know for sure.
Click to expand...
According to Wikipedia, max NTFS volume size is 256TB. Max File size is 16TB. I had my doubts about 2TB being the max as I just got to thinking my single volume RAID array (basic disk... not dynamic) is slightly larger than 2TB on an Areca ARC-1120 controller. Of course I'm using 64-bit Win Server 2K3... dunno if that makes any difference.
 
imzjustplayin said:
But what would be the point of having a 10TB array if you couldn't access it remotely with windows?
Click to expand...

Umm, I guess you missed the part where I have TWO 2.03TB arrays mapped as drives in Windows(XP Pro, 32bit).
 
imzjustplayin said:
But what would be the point of having a 10TB array if you couldn't access it remotely with windows?
Click to expand...
A 10TB array on Linux plus samba will let you have a 10TB array accessible from windows. Notice Dew's setup above - 2.03TB free. Since that's greater than 2.000TB, I'm guessing SMB reports free space as a larger-than-32-bit integer, and wouldn't have any problems dealing with huge volumes. Also, since it's a filename-based protocol (rather than inode-based like nfs) one should be able to request any filename one wants, regardless of the size of the volume.

 
Dew said:
Umm, I guess you missed the part where I have TWO 2.03TB arrays mapped as drives in Windows(XP Pro, 32bit).
Click to expand...
No, I saw that, but what if you want to have those two 2TB arrays to be contiguous? Why should I have to split up the array when I think it's unnecessary?
 
with hard drives increasing in size, a single 2TB drive isn't too far aways, shouldn't windows be looking into this?
 
mjz_5 said:
with hard drives increasing in size, a single 2TB drive isn't too far aways, shouldn't windows be looking into this?
Click to expand...

It's probably something that'll change once hard drives actually do reach that size. Remember there were 2GB drives out before FAT32 was released. People just had to partition up their drives.
 
imzjustplayin said:
No, I saw that, but what if you want to have those two 2TB arrays to be contiguous? Why should I have to split up the array when I think it's unnecessary?
Click to expand...


They are contiguous and greater than 2TB each. They just happen to be on two separate fileservers(to maximize throughput). It doesn't matter if an array is 2.000000001TB or 10TB, the fact is that is is greater than 2TB and is fully accessible by any WindowsXP machine.
 
As it was mentioned earlier, the 2TB array is a "32bit limit". Its not really a 32bit limit for OS per se, but a limit of MBR. I have a Windows 2000 32bit server with SP1 (or higher I forget) installed and it allows me to use GPT instead of MBR. With an Areca controller I have an array in excess of 2TB.

IOP341hdtach256MB.jpg


For what its worth, the Red line is the array on my Areca 1231, and the Blue line is when the same array was on my Areca 1230. The difference in IO processors is staggering.
 
pissboy said:
As it was mentioned earlier, the 2TB array is a "32bit limit". Its not really a 32bit limit for OS per se, but a limit of MBR. I have a Windows 2000 32bit server with SP1 (or higher I forget) installed and it allows me to use GPT instead of MBR. With an Areca controller I have an array in excess of 2TB.

IOP341hdtach256MB.jpg


For what its worth, the Red line is the array on my Areca 1231, and the Blue line is when the same array was on my Areca 1230. The difference in IO processors is staggering.
Click to expand...

Is that fibre channel? How large of an array is that and what kind of drives are those?
 
imzjustplayin said:
Is that fibre channel? How large of an array is that and what kind of drives are those?
Click to expand...
I believe that he Areca 12xx cards are PCIe cards with single or multi-lane SATA connectors.
 
imzjustplayin said:
Is that fibre channel? How large of an array is that and what kind of drives are those?
Click to expand...

12x Seagate 7200.10 500GB drives in RAID5. It works out to 5.00TB after being formatted. RAID controller is an Areca 1231ML PCI-E card with support for 12 drives.
 
Joe Fission said:
According to Wikipedia, max NTFS volume size is 256TB. Max File size is 16TB. I had my doubts about 2TB being the max as I just got to thinking my single volume RAID array (basic disk... not dynamic) is slightly larger than 2TB on an Areca ARC-1120 controller. Of course I'm using 64-bit Win Server 2K3... dunno if that makes any difference.
Click to expand...

According to the Microsoft books, NTFS is limited to 2TB.
 
protias said:
According to the Microsoft books, NTFS is limited to 2TB.
Click to expand...

http://msdn2.microsoft.com/en-us/library/aa365254.aspx

"The NTFS file system uses 64-bit cluster indexes. This capacity gives the NTFS file system the ability to address volumes of up to 16 exabytes (16 billion GB); however, Windows XP and Windows Server 2003 limit the size of an NTFS file system volume to that addressable with 32-bit clusters, which is 128 TB (using 64-KB clusters)."
 
pissboy said:
http://msdn2.microsoft.com/en-us/library/aa365254.aspx

"The NTFS file system uses 64-bit cluster indexes. This capacity gives the NTFS file system the ability to address volumes of up to 16 exabytes (16 billion GB); however, Windows XP and Windows Server 2003 limit the size of an NTFS file system volume to that addressable with 32-bit clusters, which is 128 TB (using 64-KB clusters)."
Click to expand...

I get 256TB: 2 * 32 = 4,294,967,296 * 64KB = 274,877,906,944 KB / 1,073,741,824 = 256 TB.


I also saw in that page that gretaer than 2TB is limited to dynamic volumes. Basic volumes have to be 2TB or less. Is that an arbitrary limitation (like XP not allowing volumes greater than 32GB to be formatted with FAT32.)?
 
pissboy said:
http://msdn2.microsoft.com/en-us/library/aa365254.aspx

"The NTFS file system uses 64-bit cluster indexes. This capacity gives the NTFS file system the ability to address volumes of up to 16 exabytes (16 billion GB); however, Windows XP and Windows Server 2003 limit the size of an NTFS file system volume to that addressable with 32-bit clusters, which is 128 TB (using 64-KB clusters)."
Click to expand...

Seems like Microsoft is contradicting itself from what I've read in their books to what is being said here.
 
ryan_975 said:
I get 256TB: 2 * 32 = 4,294,967,296 * 64KB = 274,877,906,944 KB / 1,073,741,824 = 256 TB.
Click to expand...
Probably, they're using a signed int. That makes 2**31 * 2**16 = 2**47 = 128 TiB.

protias: NTFS handles large volumes fine. That doesn't mean they can go on MBR (the standard partition table) disks. They have a 32-bit limit, but instead of 2**32 64k clusters it's 2**32 512-byte disk sectors. That leads to a smaller maximum volume size than NTFS could otherwise handle.
 
unhappy_mage said:
Probably, they're using a signed int. That makes 2**31 * 2**16 = 2**47 = 128 TiB.

protias: NTFS handles large volumes fine. That doesn't mean they can go on MBR (the standard partition table) disks. They have a 32-bit limit, but instead of 2**32 64k clusters it's 2**32 512-byte disk sectors. That leads to a smaller maximum volume size than NTFS could otherwise handle.
Click to expand...

Ah, gotcha. So the MS books don't tell you about the cluster size and make me look like an idiot. :rolleyes:
 
While that does explain a LOT, I find it hard to believe they didn't have databases more than 2TB in 2000 when they didn't have XP 64 or itanium based systems.. So, what would you do in that situation? Or even 16TB!
 
imzjustplayin said:
While that does explain a LOT, I find it hard to believe they didn't have databases more than 2TB in 2000 when they didn't have XP 64 or itanium based systems.. So, what would you do in that situation? Or even 16TB!
Click to expand...

I ran 3TB in XP no problem. Just make a pair of 1.5TB arrays and stripe them in windows.
 
pissboy said:
I ran 3TB in XP no problem. Just make a pair of 1.5TB arrays and stripe them in windows.
Click to expand...


While I was keen on using dynamic drives and software raid etc. in windows, after finding out that Acronis True image Enterprise edition doesn't support dynamic drives, I have no idea how to go about backing up dynamic drives. So, how does one backup a dynamic drive w/o the windows utility?
 
imzjustplayin said:
While that does explain a LOT, I find it hard to believe they didn't have databases more than 2TB in 2000 when they didn't have XP 64 or itanium based systems.. So, what would you do in that situation? Or even 16TB!
Click to expand...

There were other operating systems that allow large volumes sizes.
 
oplin said:
Areca has a nice write up on the 2tb limit here,
ftp://ftp.areca.com.tw/RaidCards/Documents/Manual_Spec/Over2TB_050721.zip

Windows server and business edition of vista can handle the lba 48bit thingy to go up to 256tb i believe, regular windows xp pro and basic are limited to 2tb. But you can change the cluster size to get it to 16tb, i might be wrong but most of that info is in that pdf i posted above.
Click to expand...


Alright, so the server editions support GPT but not the consumer editions yet. So, what I'm wondering is, if you've got a Server Edition of Windows on a box with a 10TB array, how would you access that 10TB array on an XP Pro system?

(Windows 2000 Adv. Server system has a 10TB array/volume that is NON dynamic [hopefully possible] and you've got a XP Pro system accessing the server, is it allowed to access that array? The reason why it bothers me is because while you could have an OS capable of holding all of that data, you may not be able to access that with a typical computer.
 
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