RHCE QUESTION SAMPLE - LVM

 LVM...


RHCE QUESTION SAMPLE-LVM
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One Logical Volume is created named as myvol under vo volume group and is mounted. The Initial Size of that Logical Volume is 124MB. Make successfully that the size of Logical Volume 245MB without losing any data. The size of logical volume 240MB to 255MB will be acceptable.

Answer and Explanation:
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1. First check the size of Logical Volume: lvdisplay /dev/vo/myvol
2. Increase the Size of Logical Volume: lvextend -L+121M /dev/vo/myvol
3. Make Available the size on online: resize2fs /dev/vo/myvol
4. Verify the Size of Logical Volume: lvdisplay /dev/vo/myvol
5. Verify that the size comes in online or not: df -h

Explanation:
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We can extend the size of logical Volume using the lvextend command. As well as to decrease the
size of Logical Volume or lvreduce -L-100M /dev/vo/myvol to reduce , use the lvresize command. In LVM v2 we can extend the size of Logical
Volume without unmount as well as we can bring the actual size of Logical Volume on online using
ext2online command.


QUESTION NO:X
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One Logical Volume named lv1 is created under vg0. The Initial Size of that Logical Volume is 100MB. Now you required the size 500MB. Make successfully the size of that Logical Volume 500M without losing any data. As well as size should be increased online.

Answer and Explanation:
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1. Verify the size of Logical Volume: lvdisplay /dev/vg0/lv1
2. Verify the Size on mounted directory: df -h or df -h mounted directory name
3. Use : lvextend -L+400M /dev/vg0/lv1
4. resize2fs /dev/vg0/lv1 à to bring extended size online.
5. Again Verify using lvdisplay and df -h command.

Explanation:
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The LVM system organizes hard disks into Logical Volume (LV) groups. Essentially, physical hard
disk partitions (or possibly RAID arrays) are set up in a bunch of equal-sized chunks known as
Physical Extents (PE). As there are several other concepts associated with the LVM system, let's
start with some basic definitions:
* Physical Volume (PV) is the standard partition that you add to the LVM mix. Normally, a physical
volume is a standard primary or logical partition. It can also be a RAID array.
* Physical Extent (PE) is a chunk of disk space. Every PV is divided into a number of equal sized
PEs. Every PE in a LV group is the same size. Different LV groups can have different sized PEs.
* Logical Extent (LE) is also a chunk of disk space. Every LE is mapped to a specific PE.
* Logical Volume (LV) is composed of a group of LEs. You can mount a filesystem such as /home
and /var on an LV.
* Volume Group (VG) is composed of a group of LVs. It is the organizational group for LVM. Most
of the commands that you'll use apply to a specific VG.