32TB RAID0 Volume Shows Up as 677GB When Mounted

R

robegan99

Hello,

I'm using an LSI MegaRAID 9260 controller with 12 x 3TB SAS drives in a hardware RAID0 volume. I'm trying to mount the volume under FreeBSD 8.1, but when I do, it only shows a size of 677GB.

I've tried two methods to get it running: sysinstall, and command line with dd, fdisk, bsdlabel, etc.

Steps with Sysinstall:
1) Go into fdisk, choose the device (it's mfid2 on my system)
2) Select A (use entire disk)
3) Select W and Q to write and finish
4) Go into Disklabel Editor
5) Select the device (now mfid2s1)
6) Hit C for create, use all available space
7) Choose File System (not swap)
8) Hit W to write changes
9) Exit Sysinstall
10) mount the partiton, and run df -h to see that it's only 677GB

Steps from the command line:
1) dd if=/dev/zero of=/dev/mfid2 bs=1k count=1
2) fdisk -BI mfid2
3) bsdlabel -B -w mfid2s1 auto
4) bsdlabel -e mfid2s1
5) newfs /dev/mfid2s1
6) mount /dev/mfid2s1 /mnt
7) Run df -h and see that /mnt is 677GB

Can anybody suggest a way to get this to work? MegaCli reports the correct size for the disk group, the physical disks are fine, etc. Any help would be appreciated. Thanks!
 
This is probably due to the limitations of the MBR partitioning scheme. Try using GPT.
 
SirDice said:
This is probably due to the limitations of the MBR partitioning scheme. Try using GPT.
Click to expand...

Yeah, that would be it. MBR partitioning cannot be used for disks over 2 TB in size. You either need to use GPT (which is cleaner / nicer to use anyway), or some kind of volume manager to split it into 2 TB logical volumes.
 
The diskinfo output is as follows:

Code: 
# diskinfo -v mfid2
mfid2
        512             # sectorsize
        36000415875072  # mediasize in bytes (33T)
        70313312256     # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        4376801         # Cylinders according to firmware.
        255             # Heads according to firmware.
        63              # Sectors according to firmware.
                        # Disk ident.
I was able to get it to mount by just doing a [cmd=]dd if=/dev/zero of=/dev/mfid2[/cmd] and [cmd=]newfs /dev/mfid2[/cmd] and then mounting which then shows up as a 29TB partition. What happens to the other 4TB? I'm not familiar with prepping it with GPT. Would this be better? (and yes, I'm a FreeBSD newb).
 
robegan99 said:
What happens to the other 4TB?
Click to expand...

UFS reserves 10% of the volume for root by default.

It's not strictly necessary to partition the device, unless you need to. You've already created a filesystem directly on the device and can use it as-is if you want to.

If you want to partition it with GPT, try the following:

Code: 
# gpart create -s gpt mfid2
# gpart add -t freebsd-ufs mfid2
# newfs /dev/mfid2p1

This will create a GPT partition table with a single partition spanning the whole device.

(I'm assuming you won't be wanting to boot from this device)
 
jem said:
UFS reserves 10% of the volume for root by default.

It's not strictly necessary to partition the device, unless you need to. You've already created a filesystem directly on the device and can use it as-is if you want to.

If you want to partition it with GPT, try the following:

Code: 
# gpart create -s gpt mfid2
# gpart add -t freebsd-ufs mfid2
# newfs /dev/mfid2p1

This will create a GPT partition table with a single partition spanning the whole device.

(I'm assuming you won't be wanting to boot from this device)
Click to expand...

I did exactly as you described above, worked great. Thanks!
 
You must log in or register to reply here.
Back
Top