Hi we have a centOS server running XEN. My problem is that there is 3*500gig HHDs in RAID 5 config. but when I do a df -H I get this:
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/Vol00-SysRoot 51G 30G 19G 62% /
/dev/hda1 255M 18M 225M 8% /boot
/dev/hdb1 255M 6.4M 236M 3% /boot2
/dev/hdc1 255M 6.4M 236M 3% /boot3
tmpfs 4.2G 0 4.2G 0% /dev/shm.
as you can see there is only 50 gig, which is not enough.

The Server was installed by someone else, along with the XEN. Is there something I am missing? because to my knowledge there must be 1TB available.

Please assist.

Are you running that cmd from the host system?
Show the results of

cat /etc/fstab

fdisk -l

both as root.

[root@vmhost2 ~]# cat /etc/fstab
/dev/Vol00/SysRoot / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
LABEL=/boot2 /boot2 ext3 defaults 1 2
LABEL=/boot3 /boot3 ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/Vol00/SysSwap swap swap defaults 0 0

[root@vmhost2 ~]# fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 32 257008+ 83 Linux
/dev/sda2 33 60801 488126992+ fd Linux raid autodetect

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 32 257008+ 83 Linux
/dev/sdb2 33 60801 488126992+ fd Linux raid autodetect

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdc1 * 1 32 257008+ 83 Linux
/dev/sdc2 33 60801 488126992+ fd Linux raid autodetect

Disk /dev/md0: 999.6 GB, 999683522560 bytes
2 heads, 4 sectors/track, 244063360 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md0 doesn't contain a valid partition table

Hi,

The server seems to be running LVM over MD raid.

Could you please inspect (and paste here) the output of

pvdisplay
vgdisplay
lvdisplay
cat /proc/mdstat

Robert

[root@vmhost2 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/md0
VG Name Vol00
PV Size 931.03 GB / not usable 28.50 MB
Allocatable yes
PE Size (KByte) 32768
Total PE 29792
Free PE 27993
Allocated PE 1799
PV UUID tBqUJz-nh4Z-Z8KF-6Loz-jLYV-aC7K-VKrBdo

[root@vmhost2 ~]#

[root@vmhost2 ~]# vgdisplay
--- Volume group ---
VG Name Vol00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 9
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 4
Open LV 4
Max PV 0
Cur PV 1
Act PV 1
VG Size 931.00 GB
PE Size 32.00 MB
Total PE 29792
Alloc PE / Size 1799 / 56.22 GB
Free PE / Size 27993 / 874.78 GB
VG UUID 4o8SqH-zcc3-13oF-Refy-zve1-ycdm-r5294j

[root@vmhost2 ~]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sdc2[1] sdb2[2] sda2[0]
976253440 blocks level 5, 256k chunk, algorithm 2 [3/3] [UUU]

unused devices: <none>
[root@vmhost2 ~]#

[root@vmhost2 ~]# lvdisplay
--- Logical volume ---
LV Name /dev/Vol00/SysRoot
VG Name Vol00
LV UUID j5AFJU-qBp4-yGm9-WFU1-6k3w-vhPl-K6wcU4
LV Write Access read/write
LV Status available
# open 1
LV Size 48.81 GB
Current LE 1562
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

--- Logical volume ---
LV Name /dev/Vol00/SysSwap
VG Name Vol00
LV UUID 9oisiU-SqSx-Sn2S-aFat-bJPV-0uF4-a6iWaX
LV Write Access read/write
LV Status available
# open 1
LV Size 2.00 GB
Current LE 64
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1

--- Logical volume ---
LV Name /dev/Vol00/kloxo_vmswap
VG Name Vol00
LV UUID 6tnl1S-NwSh-rIDW-v2BS-lrUE-B8AX-cHEvEU
LV Write Access read/write
LV Status available
# open 1
LV Size 512.00 MB
Current LE 16
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2

--- Logical volume ---
LV Name /dev/Vol00/kloxo_rootimg
VG Name Vol00
LV UUID 3cl9rg-cJ0z-3tCu-9jTc-WGDL-93JB-hrproO
LV Write Access read/write
LV Status available
# open 1
LV Size 4.91 GB
Current LE 157
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:3

[root@vmhost2 ~]#

Yep, the /proc/mdstat output and this

PV Name /dev/md0
VG Name Vol00
PV Size 931.03 GB / not usable 28.50 MB
Allocatable yes
PE Size (KByte) 32768
Total PE 29792
Free PE 27993
Allocated PE 1799

confirms you've got RAID and only 1799 physical extents allocated out of a total of 29792.

Total size of md0 is ~ 1TB (PV Size 931.03 GB / not usable 28.50 MB) unusable is reserved for LVM hdrs.

http://tldp.org/HOWTO/LVM-HOWTO/
You can pretty much assume LVM v2 there

You have 874.78 GB available to use in your (single) volume group.

You can either extend your existing logical volume Vol00-SysRoot (man lvextend) or create new logical volumes (man lvcreate) and mount them as needed.

Check the LVM howto that Chris linked to, it's very useful.

Thanks for the help guys. I got all my hard drive space now.