Q: I have a LVM(logical volume) in my Linux, i need to extend the size without offline the logical volume.

A:

You will need to ensure you have spaces in volume group. Assuming the VG name is : VolGroup00.

[root@linux1 data]# vgdisplay
— Volume group —
VG Name               VolGroup00
System ID
Format                lvm2
Metadata Areas        1
Metadata Sequence No  10
VG Access             read/write
VG Status             resizable
MAX LV                0
Cur LV                8
Open LV               8
Max PV                0
Cur PV                1
Act PV                1
VG Size               1.36 TB
PE Size               32.00 MB
Total PE              44703
Alloc PE / Size       28570 / 872.81 GB
Free  PE / Size       16133 / 524.16 GB
VG UUID               d2vwa2-6JHI-lTXJ-0WHg-iXhv-6COc-h01kf6

According to “Free PE/Size” you have 524.16GB left . Then you are good to proceed with the steps.

Lets check the current size of the LV you want to resize

[root@linux1 data]# df -h .
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-lvdata
296G  191M  281G   1% /data

Lets start increasing the size!

[root@linux1 data]# lvextend -L+20G /dev/VolGroup00/lvdata
Extending logical volume lvdata to 320.00 GB
Logical volume lvdata successfully resized

Then resize it live!

[root@linux1 data]# resize2fs /dev/VolGroup00/lvdata
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VolGroup00/lvdata is mounted on /data; on-line resizing required
Performing an on-line resize of /dev/VolGroup00/lvdata to 83886080 (4k) blocks.
The filesystem on /dev/VolGroup00/lvdata is now 83886080 blocks long.

The final output you are looking for 🙂

[root@linux1 data]# df -h .
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-lvdata
315G  195M  299G   1% /data

Easy right? The original guide in Redhat showed “ext2online” but i don’t see it in my /sbin ! Luckily my best friend google told me resize2fs is the new method 🙂 Redhat you should update your documentation!