2009/10/23 <malahal@us.ibm.com>: > Morten Torstensen [morten@mortent.org] wrote: >> Why cannot the mirrorlog be stored persistently in one or more LEs in >> the LV? Why the need for a seperate PV for this? > > For better redundancy... That is something I do not clearly see. I am not going to enumarate em all, but mdadm stores the bitmap on each mirror leg, HP-UX LVM store the MWC on each mirror leg .... what makes them less redundant? If we came to loose the LVM2 mirror third log device, what would happen (you already answered me on this topic that the mirror would stop). I saw that there is some work being done to add a fourth log device to address this SPOF. I think the current implementation, by trying to be the MOST redundant one, is getting too complex, or too expensive (each mirror device requiring 3 or 4 devices even if the 1 or 2 log devices are a few Megs) that one would, in the best case, use corelog instead, or partition the drives to mirror with 1 small log partition and the remaining space for data : both cases got off of the redundancy targeted. Worst case one would use mdadm as underlying RAID. > >> Since most servers I work with have two disks for the system, this force >> me to use md for mirroring, adding unneeded complexity for a simple mirror. > > Use "--alloc anywhere" to place the log LV on one of them when you > create your mirror. > It still requires/creates a log LV ? > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ > Brem _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
