mkfs.xfs created filesystem larger than underlying device

[Michael Moody]

Hello all.

I recently created an XFS filesystem on an x86_64 CentOS 5.3 system. I used all tools in the repository:

Xfsprogs-2.9.4-1
Kernel 2.6.18-128.1.10.el5.centos.plus

It is a somewhat complex configuration of:

Areca RAID card with 16 1.5TB drives in a RAID 6 with 1 hotspare (100GB volume was created for the OS, the rest was one large volume of ~19TB)
I used pvcreate /dev/sdb to create a physical volume for LVM on the 19TB volume.
I then used vgcreate to create a volume group of 17.64TB
I used lvcreate to create 5 logical volumes, 4x4TB, and 1x1.5TB
On top of those logical volumes is drbd (/dev/drbd0-/dev/drbd4)
On top of the drbd volumes, I created a volume group of 17.50TB (/dev/drbd0-/dev/drbd4)
I created a logical volume of 17.49TB, upon which was created an xfs filesystem with no options (mkfs.xfs mkfs.xfs /dev/Volume1-Rep-Store/Volume1-Replicated -L Replicated)

The resulting filesystem is larger than the underlying logical volume:

--- Logical volume ---
  LV Name                /dev/Volume1-Rep-Store/Volume1-Replicated
  VG Name                Volume1-Rep-Store
  LV UUID                fB0q3f-80Kq-yFuy-NjKl-pmlW-jeiX-uEruWC
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                17.49 TB
  Current LE             4584899
  Segments               5
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:5

/dev/mapper/Volume1--Rep--Store-Volume1--Replicated
                       18T  411M   18T   1% /mnt/Volume1

Why is this, and how can I fix it?

Thanks,
Michael
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://oss.sgi.com/pipermail/xfs/attachments/20090624/238ae76c/attachment.htm>