fdisking large volumes
Hi, When playing with a dual Opteron box with a large RAID5 (6 TB) attached I noticed a couple of very strange things with fdisk. Distro is SL93 on the latest YOU level. When a volume (say, /dev/sdb) is larger than 2 TB fdisk does not allow me to create partitions bigger than 1.2 TB, and it does not allow me to assign the remaining space to more partitions. When the volume is smaller, I can assign the whole volume to a single partition (e.g. 1.4 TB). Maybe 64 Bit LBA is the bad guy. We tried two SATA RAID Adapters: - Areco ARC-1160. This one allows you to create volumes smaller than 2 GB with standard LBA (32 Bit), > 2 TB with 64 Bit LBA, and a mode "For Windows" whatever this means. - 3ware 9500S 8mi. Ths controller does not allow you to create volumes at all, you get always the entire RAID as a volume. Very spartanic if you ask me. What's going on here? TIA -- Workers of the world, arise! You have nothing to lose but your chairs.
On Sun, Aug 07, 2005 at 09:02:30AM +0200, Harald Milz wrote:
Hi,
When playing with a dual Opteron box with a large RAID5 (6 TB) attached I noticed a couple of very strange things with fdisk. Distro is SL93 on the latest YOU level.
When a volume (say, /dev/sdb) is larger than 2 TB fdisk does not allow me to create partitions bigger than 1.2 TB, and it does not allow me to assign the remaining space to more partitions. When the volume is smaller, I can assign the whole volume to a single partition (e.g. 1.4 TB).
The old DOS partition format does not support more than 2TB. Use EFI partitions or LVM directly on disk. -Andi
Andi Kleen
On Sun, Aug 07, 2005 at 09:02:30AM +0200, Harald Milz wrote:
When a volume (say, /dev/sdb) is larger than 2 TB fdisk does not allow me to create partitions bigger than 1.2 TB, and it does not allow me to assign the remaining space to more partitions. When the volume is smaller, I can assign the whole volume to a single partition (e.g. 1.4 TB).
The old DOS partition format does not support more than 2TB. Use EFI partitions
Yes I know but I ran against a 1.2 TB wall not 2 TB as I expected, and why is there a difference between volumes smaller than 2 TB and larger than that as far as fdisking? -- Never tell a lie unless it is absolutely convenient.
I am not sure what you mean below Andi.... I too have run into 2 TB filesystem limitations and would love to know something definitive on this. What partioning tool are you referring to? I typically use the partitioner in yast.... My own experience is mostly with SLES9. I have multiple 3 TB raids. They come configured by the manufacturer to have a 2 TB per volume limit; thus, each raid shows up as 2 1.5 TB devices in the Partitioner. However I recently was told there was a hidden option to remove this limitation. I did so and created a 3 TB single volume. Now in SLES9 Partioner that showed up wrong. Updating to SP1 the device was shown to be the correct size. It even allowed me to create a 3 TB partition, format, and mount it. However doing a df showed the filesystem to only be 1 TB (whatever the overflow was). When I re-opened the Partitioner my previously 3 TB partition was now 1 TB (although the device still showed up correctly). I can only assume the disk tools are not fully compliant yet..... I have not tried SP2. To give this list some pro content I think I got originally tried 9.2 Pro and got the same results as sles9 sp1. Joe Andi Kleen wrote:
On Sun, Aug 07, 2005 at 09:02:30AM +0200, Harald Milz wrote:
Hi,
When playing with a dual Opteron box with a large RAID5 (6 TB) attached I noticed a couple of very strange things with fdisk. Distro is SL93 on the latest YOU level.
When a volume (say, /dev/sdb) is larger than 2 TB fdisk does not allow me to create partitions bigger than 1.2 TB, and it does not allow me to assign the remaining space to more partitions. When the volume is smaller, I can assign the whole volume to a single partition (e.g. 1.4 TB).
The old DOS partition format does not support more than 2TB. Use EFI partitions or LVM directly on disk.
-Andi
----- Original Message -----
From: "Joe Georger"
I am not sure what you mean below Andi.... I too have run into 2 TB filesystem limitations and would love to know something definitive on this. What partioning tool are you referring to? I typically use the partitioner in yast....
My own experience is mostly with SLES9. I have multiple 3 TB raids. They come configured by the manufacturer to have a 2 TB per volume limit; thus, each raid shows up as 2 1.5 TB devices in the Partitioner. However I recently was told there was a hidden option to remove this limitation. I did so and created a 3 TB single volume. Now in SLES9 Partioner that showed up wrong. Updating to SP1 the device was shown to be the correct size. It even allowed me to create a 3 TB partition, format, and mount it. However doing a df showed the filesystem to only be 1 TB (whatever the overflow was). When I re-opened the Partitioner my previously 3 TB partition was now 1 TB (although the device still showed up correctly).
I can only assume the disk tools are not fully compliant yet..... I have not tried SP2. To give this list some pro content I think I got originally tried 9.2 Pro and got the same results as sles9 sp1.
Joe
Andi Kleen wrote:
On Sun, Aug 07, 2005 at 09:02:30AM +0200, Harald Milz wrote:
Hi,
When playing with a dual Opteron box with a large RAID5 (6 TB) attached I noticed a couple of very strange things with fdisk. Distro is SL93 on the latest YOU level. When a volume (say, /dev/sdb) is larger than 2 TB fdisk does not allow me to create partitions bigger than 1.2 TB, and it does not allow me to assign the remaining space to more partitions. When the volume is smaller, I can assign the whole volume to a single partition (e.g. 1.4 TB).
The old DOS partition format does not support more than 2TB. Use EFI partitions or LVM directly on disk.
-Andi
Or even better use parted from the command line. I use it to create my 3TB partitions on my 3ware controllers. Brad Dameron SeaTab Software www.seatab.com
On Tue, Aug 09, 2005 at 12:54:53PM -0400, Joe Georger wrote:
I am not sure what you mean below Andi.... I too have run into 2 TB filesystem limitations and would love to know something definitive on this. What partioning tool are you referring to? I typically use the partitioner in yast....
You can use 4TB if you assume all tools don't have signedness issues with handling the 32bit sector number. I wouldn't bet on it, Staying in the positive range and limiting to 2TB is much safer. -Andi
participants (4)
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Andi Kleen -
Brad Dameron -
Harald Milz -
Joe Georger