Resizing a logical volume on Oracle Enterprise Linux (OEL) 5.6


I was running OEL 5.6 as the guest OS on VMWare hosted in a Fedora machine.
The machine had a 20Gb virtual disk and I had initially allocated about 11Gb to the root system.
I know it is not within best practice, but I was doing some quick configuration tests with Oracle so I had decided to install software and database files in the root file system.
Well, a couple of oracle releases later I had run out of space in the file system.


So the scenario was:
  1. The VM had a 20Gb disk allocated, but
  2. The disks partitions were only about 12Gb big, divided in two logical volumes: lv00 mapped to the root file system and lv01 used by the swap file system.
  3. Its usually pretty easy to extend a file system. Just unmount it and run a couple of commands. But you can't unmount the root file system and keep the system going.

(?) So how to extend the logical volume and the file system?
  • Well, it turns out that this can be done without having to unmount the root file system for systems with a 2.6 kernel. You just need to use lvextend and resize2fs.

Here is some output of the initial scenario:
jdoe@quark # fdisk -l

Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          19      152586   83  Linux
/dev/sda2              20        2610    20812207+  8e  Linux LVM

Disk /dev/dm-0 doesn't contain a valid partition table

Disk /dev/dm-1: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/dm-1 doesn't contain a valid partition table

jdoe@quark # df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VG00-LV00
                       12G   11G     0 100% /
/dev/sda1             145M   20M  118M  15% /boot
tmpfs                 944M     0  944M   0% /dev/shm

The output of vgdisplay:
jdoe@quark # vgdisplay
--- Volume group ---
VG Name               VG00
System ID             
Format                lvm2
Metadata Areas        1
Metadata Sequence No  3
VG Access             read/write
VG Status             resizable
MAX LV                0
Cur LV                2
Open LV               2
Max PV                0
Cur PV                1
Act PV                1
VG Size               19.84 GB
PE Size               32.00 MB
Total PE              635
Alloc PE / Size       439 / 13.72 GB
Free  PE / Size       196 / 6.12 GB
VG UUID               y8WrXG-06ej-erEH-k3QV-fqvy-VJ8O-1hV4uT

The output of pvscan:
jdoe@quark # pvscan
PV /dev/sda2   VG VG00   lvm2 [19.84 GB / 6.12 GB free]
Total: 1 [19.84 GB] / in use: 1 [19.84 GB] / in no VG: 0 [0   ]

Solution:
  • Since the total disk space on /dev/sda was already allocated to the Volume group,
    what I needed to do was just to extend the logical volume to use the free space in the volume group.

jdoe@quark # lvextend -l+196 /dev/VG00/LV00
Extending logical volume LV00 to 17.84 GB
Logical volume LV00 successfully resized
jdoe@quark #
jdoe@quark # resize2fs /dev/VG00/LV00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VG00/LV00 is mounted on /; on-line resizing required
Performing an on-line resize of /dev/VG00/LV00 to 4677632 (4k) blocks.
The filesystem on /dev/VG00/LV00 is now 4677632 blocks long.

And that did it.
Here are some printouts of the final scenario:
jdoe@quark # fdisk -l

Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          19      152586   83  Linux
/dev/sda2              20        2610    20812207+  8e  Linux LVM

jdoe@quark # df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VG00-LV00
                       18G   11G  5.7G  66% /
/dev/sda1             145M   20M  118M  15% /boot
tmpfs                 944M     0  944M   0% /dev/shm

jdoe@quark # vgdisplay
--- Volume group ---
VG Name               VG00
System ID             
Format                lvm2
Metadata Areas        1
Metadata Sequence No  4
VG Access             read/write
VG Status             resizable
MAX LV                0
Cur LV                2
Open LV               2
Max PV                0
Cur PV                1
Act PV                1
VG Size               19.84 GB
PE Size               32.00 MB
Total PE              635
Alloc PE / Size       635 / 19.84 GB
Free  PE / Size       0 / 0   
VG UUID               y8WrXG-06ej-erEH-k3QV-fqvy-VJ8O-1hV4uT

Mounting an NTFS filesystem on Oracle Enterprise Linux


To access an NTFS file system from Linux (OEL) you need either:
  • (a) need to have NTFS support compiled in the kernel or
  • (b) need to download and install packages that allow NTFS file systems to be mounted in userspace

Historically, few of the Linux distributors have ship with out-of-the-box support for NTFS file systems. As pointed out here, while there is a lot of public information about about MSDOS and VFAT, Microsoft has not published much details of NTFS, so the implementations vary in stability and features.

Initially you should check whether NTFS modules are already installed on your system.
$ ls -l /lib/modules/2.6.32-35-generic/kernel/fs/ | grep ntfs
drwxr-xr-x 2 root root  4096 2011-11-08 09:12 ntfs
In case no modules are found, you need to download and install NTFS packages.
  • NTFS-3G is an open source implementation of Microsoft's NTFS file system that includes read and write support.
  • NTFS-3G developers use the FUSE file system to facilitate development and to help with portability

Step 1: Download fuse and ntfs-3g
fuse: get it from http://www.atrpms.net/dist/el5/fuse/ or http://sourceforge.net/projects/fuse/files/fuse-2.X/
ntfs-3g: You can download it from http://pkgs.repoforge.org/fuse-ntfs-3g/

Step 2: Install fuse components
# yum install fuse
Loaded plugins: rhnplugin, security
This system is not registered with ULN.
ULN support will be disabled.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package fuse.i386 0:2.7.4-8.el5 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved
================================================================================================
Package            Arch             Version             Repository           Size
================================================================================================
Installing:
fuse               i386             2.7.4-8.el5         ol5_u6_base          84 k

Transaction Summary
================================================================================================
Install       1 Package(s)
Upgrade       0 Package(s)

Total download size: 84 k
Is this ok [y/N]: y
Downloading Packages:
fuse-2.7.4-8.el5.i386.rpm                                                  |  84 kB     00:00     
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing: fuse    1/1 
Installed: fuse.i386 0:2.7.4-8.el5                                                                                                      

Complete!
#
  • If you can't perform a yum installation, you can try installing fuse from your OEL media or performing a manual installation with the package downloaded from forgesource, as described here.

Step 3: Install fuse-ntfs-3g
# rpm -Uvh fuse-ntfs-3g-2010.5.22-1.el5.rf.i386.rpm 
warning: fuse-ntfs-3g-2010.5.22-1.el5.rf.i386.rpm: Header V3 DSA signature: NOKEY, key ID 6b8d79e6
Preparing...                ########################################### [100%]
1:fuse-ntfs-3g           ########################################### [100%]

Step 4: Mount the NTFS file system.
  • Once installed, reconnect the device and OEL should recognize it automatically
# mount.ntfs-3g