Huge Storage Array 17TB partition - xfs/ext3 setup problems

[humbletech99]

I've got a large storage volume which is a Raid6 giving me 17TB usable. However, I am having significant problems trying to set it up with a filesystem as it's larger than the other two 6TB volumes that I used previously.

I have used the GPT partition type in order to deal with the large block device and created it as one large volume which I want to put either ext3 or xfs on.

Firstly, ext3 would not go beyond 8TB apparently without increasing my block size, which linux doesn't seem to want to do, so I decided to try xfs instead. So I did a basic

mkfs.xfs /dev/sdb1

to create the filesystem as I'm not so familiar with xfs options like superblock spacing, stride etc..

The command returned suspiciously quickly, and when I try to mount the partition I get the error below:

mount /dev/sdb1 /mnt/raid
mount: Argument list too long

I'm in Knoppix 5.1 at the moment until this is set up and it seems to have detected everything properly so far...

Can anyone give any guidance or feedback on this?

[matonb]

Hi humbletech99,

TBH with a parition that size I would use LVM...

[humbletech99]

why? LVM just joins things together, you still need a filesystem on top...

so I'm back to my filesystem problem....

[matonb]

why? LVM just joins things together, you still need a filesystem on top...

so I'm back to my filesystem problem....

Oops silly me.

Actually I think your currently "stuffed". The 4Kb block/page limit on x86 systems will cap your capacity at 16TB...

Wikipedia - Capacity

Old but still relevant:

64 bit block devices

[i92guboj]

Ext4 uses 48 bits for block numbers, so, it can handle up to 2^60 (exabyte), which is in the range of a million of terabytes. High enough. There are two problems though: once you use such incompatible feature, you can't mount your system as ext3 anymore, breaking backwards compatibility.

The other evident problem is that ext4 is not finished, is not stable, can still change (breaking your filesystem layout and all your data), and shouldn't definitely be used in a production system.

It's however something to watch out for in the -near, I hope- future.

Besides that, zfs is *the fs* when it comes to big volumes. It's available for opensolaris, so you might want to look at that as well. There are projects to port is to freebsd and linux (using fuse), but I have obsolutely no clue how's that going, or if it's usable at all.

ZFS FAQ at OpenSolaris.org

[humbletech99]

Thanks for the feedback guys. For your information, I have reinstalled as 64-bit since we always buy Opteron servers which gets me around the 16TB limit, but ext3 still didn't want to go above 8TB, so I switched to xfs and problem solved.