reducing space using LVM in linux

Thanks for the reply

- First of all did you create a pertition of type LVM before adding the disk to LVM ?
yes did create the partition of type LVM with the fdisk and t then giving a hexa decimal value 8e

- How is your current disks organized? Can you post your /etc/fstab and mout outputs here ?
vim /etc/fstab
/dev/VolGroup00/LogVol05 /                       ext3    defaults        1 1
LABEL=/boot1            /boot                   ext3    defaults        1 2
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
/dev/VolGroup00/LogVol03 /opt                    ext3    defaults        1 2
proc                    /proc                   proc    defaults        0 0
sysfs                   /sys                    sysfs   defaults        0 0
/dev/VolGroup00/LogVol00 /tmp                    ext3    defaults        1 2
/dev/VolGroup00/LogVol04 /usr                    ext3    defaults        1 2
/dev/VolGroup00/LogVol02 /var                    ext3    defaults        1 2
LABEL=SW-cciss/c0d0p3   swap                    swap    defaults        0 0
LABEL=SW-cciss/c0d0p5   swap                    swap    defaults        0 0
/dev/VolGroup00/LogVol01                /home           ext3    defaults,usrquota,grpquota      1 2

- Are you sure that your /home folder did not expand over your new volume ? In this case removing the volume would break the integrity of your /home volume..

Yes i am sure  as i still had the space in the old hard disk

also request your opinion on the following
select the  partition from the LVM window the one which is increased and click on Edit Properties and reduce the extents

Thanks in advance.
Please help me on this

Sir, forgot to add mount points , posted the mount points
# mount
/dev/mapper/VolGroup00-LogVol05 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/cciss/c0d0p1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
/dev/mapper/VolGroup00-LogVol03 on /opt type ext3 (rw)
/dev/mapper/VolGroup00-LogVol00 on /tmp type ext3 (rw)
/dev/mapper/VolGroup00-LogVol04 on /usr type ext3 (rw)
/dev/mapper/VolGroup00-LogVol02 on /var type ext3 (rw)
/dev/mapper/VolGroup00-LogVol01 on /home type ext3 (rw,acl)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/dev/ram1 on /tmp/safesquid type ext2 (rw)

Ok will you please post your

pvdisplay
vgdiplay
lvdisplay

outputs too ??

Thanks for the reply, following posted

 pvdisplay
  --- Physical volume ---
  PV Name               /dev/cciss/c0d0p2
  VG Name               VolGroup00
  PV Size               129.52 GB / not usable 22.38 MB
  Allocatable           yes (but full)
  PE Size (KByte)       32768
  Total PE              4144
  Free PE               0
  Allocated PE          4144
  PV UUID               oYwQEd-gqWN-nUwE-Cly0-vSlp-pkUK-y2t69T
   
  --- Physical volume ---
  PV Name               /dev/cciss/c0d1p1
  VG Name               VolGroup00
  PV Size               68.33 GB / not usable 21.58 MB
  Allocatable           yes (but full)
  PE Size (KByte)       32768
  Total PE              2186
  Free PE               0
  Allocated PE          2186
  PV UUID               7dTlKd-wgsr-YAg1-GshD-htCE-iFPa-4FdnBA


vgdisplay
  --- Volume group ---
  VG Name               VolGroup00
  System ID            
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  25
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                6
  Open LV               6
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               197.81 GB
  PE Size               32.00 MB
  Total PE              6330
  Alloc PE / Size       6330 / 197.81 GB
  Free  PE / Size       0 / 0  
  VG UUID               2MoUtm-H3X9-jUpm-YrT3-4lTP-Wk4C-icITid

lvdisplay
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol05
  VG Name                VolGroup00
  LV UUID                EROg4s-iZoF-DNVT-X67b-pCQ2-QBRK-cmHXsV
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                7.81 GB
  Current LE             250
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol01
  VG Name                VolGroup00
  LV UUID                Lsrgoz-cHK7-oAAx-PLdQ-n9EC-hs62-XKSDIM
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                118.75 GB
  Current LE             3800
  Segments               3
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol03
  VG Name                VolGroup00
  LV UUID                cp27OG-ajPf-yROZ-AmUQ-bnPw-8rF4-Oq5F1i
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                4.88 GB
  Current LE             156
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
   
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol00
  VG Name                VolGroup00
  LV UUID                E5YyZd-4lXP-smuP-Teth-JY7l-Axpy-8cYbwP
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                7.81 GB
  Current LE             250
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3
   
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol04
  VG Name                VolGroup00
  LV UUID                QcxYty-m2nt-LsyH-Z2LM-7JT6-Mryi-Zabpqa
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                24.41 GB
  Current LE             781
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:4
   
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol02
  VG Name                VolGroup00
  LV UUID                7Fuvms-yiyq-SY5i-iYz1-pWOa-MSyy-Y8Lkub
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                34.16 GB
  Current LE             1093
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:5
----------------------------------------------------------------------------------------

Please help



   

Ok now.

As I'm seeing from what you've post here:
- You have 2 Physical Volumes over HP Raid Adapter.
- The first one is 120 GB with the second is 70 GB
- Both are allocates to your LVM.
- From your initial question what I understand is you want to reduce the size of your home volume. (/dev/VolGroup00/LogVol01)
- You have no intention to remove the PV from the LVM you just want to keep the extra space reclaimed from your home free or later add it to another volume

In this case what you'd do is very simple:
- first of all make sure that you're root and you're not logged your /home volume
- unmount your home volume : umount /devVolGroup00/LogVol01
- check for interity: e2fsck -f /dev/VolGroup01/LogVol01
- reduce your filesystem size first: resize2fs /dev/VolGroup00/LogVol01 85G
- now reduce the size: lvreduce -L 34G /devVolGroup00/LogVol01
- check the new volume: e2fsck -f /dev/VolGroup01/LogVol01
- remount: mount -a

This is it
Cheers,
K.

Thank you very much , i will follow the steps given by you
- unmount your home volume : umount /devVolGroup00/LogVol01
- check for interity: e2fsck -f /dev/VolGroup01/LogVol01
- reduce your filesystem size first: resize2fs /dev/VolGroup00/LogVol01 85G
- now reduce the size: lvreduce -L 34G /devVolGroup00/LogVol01
- check the new volume: e2fsck -f /dev/VolGroup01/LogVol01
- remount: mount -a

But should i take the /home backup before doing the above but problem is it is a huge data where i cannot take backup , if the above is done perfectly does still require backup, please suggest.

Thanks in advance.

In fact there's always a residual risk involved such operation. According to Murphy's Laws it is directly proportiona to the value of data :) So please take a backup before-head.

If you can't backup it means that you'll take this risk. Although small there's still a risk factor. Please consider this. But normally ther should not be a problem but you know :)

Good Luck,
K.
 

Thank you very much will take the data backup before proceeding. finally before closing this post have a doubt  
with the command
#system-config-lvm
lvm window opens
then select /dev/cciss/c0d1p1 ( new hard disk)70GB
remove from the volume group
 add the same again with the less space

Please suggest me will this work or this is not the proper method, request your suggestion, thanks in advance.

In fact this is not what you want:
- First of all : You don't have a problem with your Volume Group and any PV's in it. Both disks are allocated and will be allocated in the end. So though we'll be reducing one of your Logical Volumes we won't be changing your VG.
- Secondly: If you remove LVM like that your Partition will still be large and larger than your Logical volume and this is a problem. As you see in my example I am reducing the Filesystem first then the LVM.
- If you prefer to work with GUI then unmount, check and reduce your file system first.
- Lastly: LVM GUI works with "Extents" rather then Actual sizes like MB og GB. Each extent is Extent_size KB's so when you reduce your disk by 2 units your actually reducing 70 GB since at these sizes the Extent size defaults to 32 GB.

I don't know if you desire to work like that but I think my instructions were easy to understand and given in standard sizes rather than extents. So it is easier to follow but it is your system  and you should pick the best method for you.

Cheers,
K.

I am very much happy of your detailed explanation, will for sure follow your instructions, thanks again.
 

Sir, think each extent is 32mb not 32 GB  i do not know if iam wrong please correct me if i am wrong.

Yeah : )  Sorry for my typo. I guess I've correctly told 32 KB but later I was thinking about how to translate it in GB would introduce difficulty and I've mistakenly told GB instead.  

Sir. Thank you very much .

Sir i did the following:

- check for interity: e2fsck -f /dev/VolGroup01/LogVol01
- reduce your filesystem size first: resize2fs /dev/VolGroup00/LogVol01 85G
- now reduce the size: lvreduce -L 34G /devVolGroup00/LogVol01
- check the new volume: e2fsck -f /dev/VolGroup01/LogVol01

i am stuck with the e2fsck and it continously asking he Error reading writing to the block ignore the error
if i say yes
next is error reading the block then if say ignore the error for  the same is keep coming , please help me how to say yes for all once and fix this.

Sir , urgent support required please help,

i did the following:

- unmount your home volume : umount /devVolGroup00/LogVol01
- check for interity: e2fsck -f /dev/VolGroup01/LogVol01
- reduce your filesystem size first: resize2fs /dev/VolGroup00/LogVol01 75G
- now reduce the size: lvreduce -L 24G /devVolGroup00/LogVol01

when executed the e2fsck like following
- check the new volume: e2fsck -f /dev/VolGroup01/LogVol01

Getting the error  saying:
-------------------------------
/devVolGroup00/LogVol01: The File system size  according to the super blocks is 19660800blocks
The physical size of the device is 6291456 blocks
Either the superblock or the partition table is likely to be corrupt:
/devVolGroup00/LogVol01: UNEXPECTED INCONSISTENCY:Run fsck manually
----------------------------

i am running fsck but it asking  ignore error and iam saying yes from past 06 hours , request you to please help me on this.

Hi,

You need to use a command like this:

fsck -y /dev/volGroup00/LogVol1

May be there's something wrong with the initial resize. Ignore my previous note and try tihs first:

resize2fs -f /dev/VolGroup00/LogVol01 85G
 e2fsck -f -y /dev/VolGroup01/LogVol01

Also post pvdisplay, vgdisplay, lvdisplay

sir ,

my system is not booting hence booted throough the rescue mode and deleted the fartitions created by the new hard disk and when try following command

resize2fs -f /dev/VolGroup00/LogVol01 50G

following is the error message

Can't read an block bitmap while trying to resize /dev/VolGroup00/LogVol01
--------------
please help in another two hours our producation should start , reauset please

what ?? you deleted what partitions??

You were not supposed to go to rescue mode. Since this were the /home you did not need to to reboot at all!!. And if it does not reboot now.

- reboot in rescue mode
- select I want to bott mounting the disks
- then rescue mode wil mount your root unde /mnt/sysimage
- now cd to /mnt/sysimage and issue chroot /mnt/sysimage
now you're at the root of your file system
- now issue a mount and see if /home is monuted
- unmount if mouned
if not use the comamnds
lvm pvdisplay
vgdisplay
lvdisplay
and ltess se that happened there

Sir:

I am able to mount with the following commad:
chroot /mnt/sysimage
and when issued mount
i can see /home is mounted

please tell me what next , please sir