[linux-lvm] Performance impact of LVM

[Michael T. Babcock]

Mark H. Wood wrote:
> However this effect is probably down in the noise for most systems.  
> The only way to know if it's a problem for you is to measure.  I would 
> expect that, given contemporary amounts of caching on the drive, the 
> controller, and in the OS, you probably won't see it unless you are 
> driving your storage *really* hard.  If you do, dump/recreate 
> contiguously/restore will make it go away.

For database partitions we always use "lvcreate -C y" when creating LVs 
for this reason, for every other area of the system however, I haven't 
noticed almost any impact of LVM(1 or 2) except that striping is easier 
to set up than using RAID0 because there's no need to repartition.

For example, I often do something like:

lvcreate -C y -n dbdata1 -L 100G mainstore
lvcreate -I 2 -n dbtemp -L 10G mainstore