Disk space reporting inconsistencies, lvm/df

rarr · 01-18-2006, 08:55 AM

Hi,

I added a new 40GB PV to my VG and thought I'd done it all right but to me there seems to be an inconsistency between what lvm says is the disk space and what df says.

Code:

>pvscan
PV /dev/sda2   VG VolGroup00   lvm2 [68.38 GB / 0    free]
PV /dev/sdb    VG VolGroup00   lvm2 [68.50 GB / 0    free]
PV /dev/hdc2   VG VolGroup00   lvm2 [37.12 GB / 0    free]
PV /dev/hdb1   VG VolGroup00   lvm2 [37.22 GB / 0    free]
PV /dev/hdd1   VG VolGroup00   lvm2 [37.22 GB / 0    free]
PV /dev/hde1   VG VolGroup00   lvm2 [37.25 GB / 0    free]
Total: 6 [285.69 GB] / in use: 6 [285.69 GB] / in no VG: 0 [0   ]

As you can see pvscan says VolGroup00 has 285.69GB.

Code:

>df -h
/dev/mapper/VolGroup00-LogVol00   265G  227G   28G  90% /

but here df says theres only 265.

I tried resizing the filesystem but it just says this..

Code:

>ext2online  /dev/VolGroup00/LogVol00
  ext2online v1.1.18 - 2001/03/18 for EXT2FS 0.5b
  ext2online: ext2_ioctl: No space left on device

ext2online: unable to resize /dev/mapper/VolGroup00-LogVol00

Am I missing something obvious here? or have I messed it up along the way?

Cheers.

Matir · 01-18-2006, 11:14 AM

It's most likely because of the different ways of measuring 1k. Generally, hard drive manufacturers measure drives in 10^9 byte Gigabytes. Filesystems and operating systems measure the sizes in 2^30 Gigabytes (1024*1024*1024). If you convert 285 hard drive GB to binary GB (285*1000*1000*1000/1024/1024/1024) you get a number extremely close to 265GB.

rarr · 01-18-2006, 11:26 AM

hmm yeah that would appear to be the case.

Both programs are using the abbreviation G to mean a different standard of gigabyte.

I feel somehow empty inside now