Chris Gordon <chris@xxxxxxxxxxxx> writes: > Mime-Version: 1.0 > Reply-To: For users of Fedora Core releases <fedora-list@xxxxxxxxxx> > > > > Just what are the main advantages to LVM over just a > > plain jane ext2 (3) system? Is there a speed penalty > > if you are not using RAID? Any thoughts would be > > appreciated.... still updating the ole brain ROMs. Ric > > LVM gives you more flexibility. Essentially you take a disk partition > and can then cut it up into logical volumes which you then place normal > file systems on. This can allow you to expand, create and remove > filesystems without having to touch the the disk partition table or > worry about the location space on the physical disk. > > Consider this situation. You have a disk with three partitions: hda1, > hda2, and hda3. You've sized them and created file systems as based on > your best initial plans. As times moves along, you end up no longer > needed hda1 -- whatever the function of it was is no longer a > requirement/need for your system. During the same time, though, you've > filled up hda3. In this situation, if you want to recover the space for > hda1 and "add" it to hda3, you've got a good bit of work to do in moving > hda2 around. Not a pleasant situation. > > With LVM, you would have made all of hda into a single PV and then a > single VG. Within that VG you could have created 3 LVs (logical > volumes) and put the filesystems on them. Then when you no longer > needed stuff in the first file system, just unmount it and destroy that > LV. Then you could expand the third LV and grow the filesystem on it > (even can do it all online now without ever taking the box down). > > In the traditional volume example, hda2 sits in the middle of the space > you want to use and makes things rather difficult. With a volume > manager, the exact placement of things on the physical volume is > abstracted and there is no issue. The ability to easily work with the > volumes is also a plus. > > Hope that helped. Excellent response. Thanks, -pmr
