subject: Benefits of Logical Volume Manager [print this page] Benefits of Logical Volume Manager Benefits of Logical Volume Manager
Fdisk method of partitioning
Fdisk is utility and this is only partition method which was used in all the operating systems including windows, Linux, etc. still in many operating system they are following this method for partitioning but there are some limitations in this method such as
1. Tough we have 100 hard disks we cannot able combine these entire 100 disks in to a single partition
(i.e.) if you have 10 terabyte data and you have 100 hard disks each of size 100 gigabyte (GB) and if you like to save this 10 terabyte as a single file it's not possible. In this case what you have to do is you can go for a third part tool to combine all these disks or else you have to split the file and you have to save it in different drives.
2. No way of combining two or more partitions and also we can't able to combine free spaces of different disks to make a partitions.
3. unable to resize the portion while it is in online.
4. if you use this method to partition the hard disk whose size greater than 64gb , F disk does not report the correct size of the hard disk . This is because f disk uses variable which is of size 16-bit to calculate this disk size, if the disk size is greater than or equal to 64 GB it won't work properly
The problem what I have mentioned in the fourth point even Microsoft accept it and to overcome from this problem the users have to install the fix which was released by them.
Benefits of Logical volume manager
Logical volume manager is also one of the partitioning methods which is used in IBM AIX, HP UX, Linux .etc. among other operating systems IBM AIX uses only this lvm method for partitioning
Lvm was introduced mainly to overcome the drawbacks found in f disk method which we have discussed previously in the article.
1. we can able to combine 1000 hard disk in to single disk and with that single disk we can able to create a single partition (note: the disk may be of any size) this is possible by splitting each disk in to small blocks of same size called physical partition (pp) and group them in to single entity call volume group (VG)
2. We can able to able to resize the partition size at any time even during online.
3. File system can span hard disks
4. In future if you like to increase VG size you can add extra disk at any time
5. Can mirror data in separate disk
Some of the LVM components are:
Physical volume (PV)
Volume group (VG)
Physical partition (pp)
Logical volume (LV)
Logical partition (LP)
These are some benefits of LVM. In the next article we will see how to use LVM.
