On Tue, Mar 11, 2003 at 11:22:20AM +0000, Paul Furness wrote: > Hi. > > I'm trying to get LVM 1.0.7 going on our new production server. I've > never used LVM before, but based on reccommendations and looking at what > it can do, it looks like exactly what I need. > > For the reccord, it's a SMP Xeon system, running RedHat 7.3 plus current > RH patches. > > I am confused about the defualt setting for Physical Extents when you > run vgcreate on a new PV. > > Looking through the man page for vgcreate is says this: > > -s, --physicalextentsize PhysicalExtentSize[kKmMgGtT] > Sets the physical extent size on physical volumes > of this volume group. ................. The default > of 32 MB allows LV sizes of ~2TB because as many as > ~64k extents are supported per LV. > > A bit later, under "Examples." it says this: > > To create a volume group named test_vg using physical vol- > umes /dev/hdk1, /dev/hdl1, and /dev/hdm1 with default > physical extent size of 4MB: > > vgcreate test_vg /dev/sd[k-m]1 > > > So what is the default? 4M or 32M? Or something else? Or should I simply > forget about the default and pick a number? The default is 32MB, the example has not been updated. It used to be 4MB but limiting LVs to 256MB by default soon became a problem for people. > Finally, is there any documentation that's more detailed than the HOWTO, > and explains a bit more about the theory of LVM - what happens when you > change the size of existing file systems, and so on? The HowTo is ok > (although not all that great if you've never patched a kernel before), > but necessarily brief. :) Not that I know of. But if you want to know what a filesystem does when it's extended then you need filesystem documentation, not LVM documentation. -- patrick _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
