How to resize VM partition on Vmware 

                                          by Jephe Wu - http://linuxtechres.blogspot.com

Extend a LVM partition

1. from Vcenter, to edit configure, to add a new hard disk with required size
   
2.   echo "- - -" > /sys/class/scsi_host/host#/scan  for each host*  (replace # with actual numbers)
3. dmesg and cat /proc/partition to confirm new disk is added.

      4. fdisk /dev/sdb to create a new partition and use t  to change it to 8e LVM

      5 . pvcreate /dev/sdb1

     6. vgextend vg_root /dev/sdb1

     7. lvextend -l +100%FREE /dev/vg_root/lv_root

or  8. lvextend -L +20G /dev/vg_root/lv_root (if only increase 20G)

     9.  resize2fs /dev/mapper/vg_root-lv_root 

or xfs_growfs mountpoint (if it's xfs partition)

Modify existing sdb LVM PV disk size and use it in vg

1. echo "- - -" > /sys/class/scsi_host/host#/scan  for each host*  (replace # with actual numbers)

or

echo 1 > /sys/block/sdb/device/rescan

 

2.  use pvscan or  fdisk -l | grep -i sdb to confirm new disk size

3. blockdev --rereadpt /dev/sdb  to resize LVM volume size

4. pvresize /dev/sdb  to resize PV

Resize Procedure for /dev/sdb1 PV

https://access.redhat.com/solutions/57183

1. Confirm the actual storage size with fdisk -ul /dev/sdb. Observe the increased disk size. Depending on how the storage is presented, a system reboot may be necessary for this to appear.

2. Resize the partition on the disk. To achieve this, observe the starting sector in fdisk -ul /dev/sdb, then remove the partition with fdisk and re-create it with the same starting sector but the (default) last sector of the drive as the ending sector. Then write the partition table and confirm the change (and the correct starting sector) with fdisk -ul /dev/sdb.

3. Run pvresize /dev/sdb1 to grow (resize) the PV onto the rest of the expanded partition. This will create free extents within the Volume Group which then can be used to grow a Logical Volume. Running lvresize command with -r as lvresize -r will grow the filesystem within the Logical Volume as well.

Another solution would be creating a new partition under the same device starting where the first partition ended and using the rest of the cylinders to create the same, then put this new partition under LVM with the pvcreate command, extend the current VG (vgextend vg-name pv-name), then extend the current LV (lvextend) and finally resize the current filesystem (resize2fs).

Create a new LVM partition with new disk

pvcreate /dev/sdx1 

vgcreate vg01 /dev/sdx1

lvcreate -l +100%FREE -n apps vg01
mkfs -t xfs /dev/mapper/vg01_apps

For rollback

1) Unmount the mountpoint

umount -v /var/www

2) Check for filesystem error

e2fsck -f /dev/vg-repo/lv-repo

3) Reduce the logical volume

lvreduce --resize2fs -L -100G (-l 5119)  /dev/vg-repo/lv-repo

Note: use vgdisplay to record down existing used logic extent number, it's 5119 in this case before increase

4) Check for filesystem error

e2fsck -f /dev/vg-repo/lv-repo

5) Mount the filesystem back to the same mountpoint

mount /dev/vg-repo/lv-repo /var/www

6) Reduce the VG in order to release the PV /dev/sde1

vgreduce vg-repo /dev/sde1

7) Remove the PV

pvremove /dev/sde1

8) Remove the new created disk from vcenter in the backup plan?

How to convert CentOS root file system to XFS

Jephe Wu - http://linuxtechres.blogspot.com


As you know, the CentOS is a clone of Redhat Enterprise Linux. CentOS doesn't support XFS file system by default which is the same as RHEL, but CentOS provides additional kernel which has built-in XFS support. You can download it to replace the existing kernel to easily get XFS support in kernel space. But the problem is how to make your /, /usr,/var etc partition as XFS file system since you already used ext3 during installation.

This article is to guide you to do that, the following is my testing environments:

CentOS 4.1
partitions:
/dev/hda1 -/boot (ext3)
/dev/hda2 - swap
/dev/hda3 - / (ext3)
/dev/hda5 - /usr (ext3)
/dev/hda6 -/var (ext3)
/dev/hda7 - /tmp (ext3)
/dev/hda8 - /serverdata (ext3)(for storing data later, it's empty after installation)


Our objective:
convert all partitions except for /boot from default file system ext3 to XFS. Grub doesn't support XFS so we leave /boot as ext3.

Clone and XFS convert concept:
a. download XFS-enabled kernel from CentOS and install it
b. use /serverdata partition to save all server OS partitions such as /boot, /,/usr,/var,/tmp
c. boot up server using RIP(Recovery Is Possible) CD
d. format all partitions as XFS
e. copy back all data from /serverdata
f. change /etc/fstab and /boot/initrd image file
g. done. reboot

Steps:

a. download the latest RIP CD at http://www.tux.org/pub/people/kent-robotti/looplinux/rip/
download Non-X version is enough

b. download the XFS enabled supported kernel from CentOS website and install it to the server
# rpm -ivh xfs-enabled-kernel
# vi /etc/grub.conf to make sure it will boot with the new kernel next time
# reboot (make sure it can boot normally with new kernel)

c. copy the whole server OS to /serverdata, make xfs file system then copy back
c.1 reboot server with RIP CD after upgrading to xfs enabled kernel, you might want to choose the second option to skip keyboard map
c.2 login as root without password
c.3 make /serverdata partition as XFS first and backup the whole OS to /serverdata
mkfs -t xfs /dev/hda8
cd /mnt
mount /dev/hda3 hd
cd hd
mount /dev/hda1 boot
mount /dev/hda5 usr
mount /dev/hda6 var
mount /dev/hda7 tmp
mount /dev/hda8 serverdata
chroot .
tar --exclude ./boot --exclude ./proc --exclude ./serverdata -cpf - .| (cd serverdata; tar xvpf -)

c.4 umount all partitions then make xfs file systems
exit (exit from chroot environement)
cd /mnt/hd
umount usr
umount var
umount tmp
umount serverdata
umount boot
cd ..
umount hd

mkfs -t xfs -L / /dev/hda3
mkfs -t xfs -L /usr /dev/hda5
mkfs -t xfs -L /var /dev/hda6
mkfs -t xfs -L /tmp /dev/hda7
note: -L to make label for partition, be sure to use the same label name in /etc/fstab.

c.5 mount them again like c.3
cd /mnt
mount /dev/hda3 hd
cd hd
mount /dev/hda1 boot
mount /dev/hda5 usr
mount /dev/hda6 var
mount /dev/hda7 tmp
mount /dev/hda8 serverdata

c.6 copy back the whole OS from backup
(cd serverdata; tar cpf - . ) | tar xvpf -

d. make necessary changes
d.1 change /etc/fstab
cd /mnt/hd
chroot .
vi /etc/fstab (to change file system for those changed from ext3 to xfs, if you didn't use -L option in above mkfs -t xfs for /, /usr,/var,/tmp partitions, you also need to change the LABEL= to the real device name like from LABEL=/usr to /dev/hda5)

d.2 change /boot/initrd image file
cd /mnt/hd
chroot .
cp /boot/initrd.img /tmp/a (use the correct name for your initrd image, I use /boot/initrd.img here)
cd /tmp
zcat a > a1
mkdir a1.dir
cd a1.dir
cpio -iv < ../a1
modify something

vi init ( change ext3 to xfs, add xfs.ko module in init as well as lib/ folder) as follows:

[root@linuxtechres ]# more init

#!/bin/nash
mount -t proc /proc /proc
setquiet
echo Mounted /proc filesystem
echo Mounting sysfs
mount -t sysfs none /sys
echo Creating /dev
mount -o mode=0755 -t tmpfs none /dev
mknod /dev/console c 5 1
mknod /dev/null c 1 3
mknod /dev/zero c 1 5
mknod /dev/hda3 b 3 3 ---> added, hda3 is the root file system device
mkdir /dev/pts
mkdir /dev/shm
echo Starting udev
/sbin/udevstart
echo -n "/sbin/hotplug" > /proc/sys/kernel/hotplug
echo "Loading jbd.ko module"
insmod /lib/jbd.ko
echo "Loading ext3.ko module"
insmod /lib/ext3.ko
echo "Loading xfs.ko module"

insmod /lib/xfs.ko ---> added - please remember to copy xfs.ko file from /lib/modules/kernel_version/kernel/fs/xfs/xfs.ko to /lib

/sbin/udevstart
echo Creating root device
mkrootdev /dev/root
umount /sys
echo Mounting root filesystem
mount -o defaults --ro -t xfs /dev/root /sysroot ---> change ext3 to xfs
mount -t tmpfs --bind /dev /sysroot/dev
echo Switching to new root
switchroot /sysroot
umount /initrd/dev

re-generate initrd.img with xfs support

find . | cpio -co > ../c
cd ..
gzip c
cp c.gz /boot/initrd.xfs.img

change /etc/grub.conf to use this new initrd.xfs.img file.

d.3 install grub
cd /mnt/hd
chroot .
grub-install /dev/hda

After that, umount all partitions, reboot the server.