Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
/ 2004-10-05 05:26:49 -0700 \ Tim Hasson: > > I thought about something like this: > > > > ll_dev0=/dev/ll_dev_of_drbd0 > > ll_dev1=/dev/ll_dev_of_drbd1 > > size_of_ll0=$(fdisk -s $ll_dev0) > > size_of_ll1=$(fdisk -s $ll_dev1) > > > > echo "\ > > 0 $[size_of_ll0<<1] linear $ll_dev0 0 > > $[size_of_ll0<<1] $[size_of_ll1<<1] linear $ll_dev1 0" | > > dmsetup create ll_linear_for_drbd > > > > drbd.conf: disk /dev/mapper/ll_linear_for_drbd > > > > Just did man dmsetup. Very interesting, and a great suggestion btw. > > But, suppose I wanted to retire one or both of my old disks. > With LVM2, I can do "pvmove" (which requires dm-mirror in kernel/as module) > There's also helper tools such as vgreduce and vgextend which aid in the disk > subsituting process ( http://www.tldp.org/HOWTO/LVM-HOWTO/removeadisk.html ) > > Is this still possible with the dm linear mapping setup? well, in principle yes, but in fact you need to do all the funky stuff that pvmove will do for you by hand then... probably not too convenient. > >From dmsetup (8) manpage: > There are currently three simple target types available together with more > complex optional ones that implement snapshots and mirrors. > > Also, could I still do online resizing when adding disks to the lower linear > mapping? dm can do everything lvm2 can do, because lvm2 is "just a front end" (well, actually much more than that) to dm. it is just not convenient anymore, that is why lvm is there. Lars Ellenberg -- please use the "List-Reply" function of your email client.