Daniel B. [dsb@smart.net] wrote: > In the LVM Administrator's Guide, at least the one at > http://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/LV_create.html , > it says:" > > LVM maintains a small log which it uses to keep track of which regions > are in sync with the mirror or mirrors. By default, this log is kept > on disk, which keeps it persistent across reboots. You can specify > instead that this log be kept in memory with the --corelog argument; > this eliminates the need for an extra log device, but it requires that > the entire mirror be resynchronized at every reboot. > > Does that last sentence mean that _all_ the data is recopied, or just > that all _regions_ are checked and not all the data necessarily has > to be copied (perhaps only change regions have to be copied, but > unchanged regions don't)? Everything has to be re-copied because it doesn't know what is changed as the "log" is kept in memory which is lost after a reboot. > More generally, can LVM perform RAID1-style mirroring with only > two disks (without having to re-copy everything each boot) > (and, of course, being recoverable in case either disk fails)? You should be able to force LVM to create a log device on one of your two devices (--alloc anywhere) Thanks, Malahal. _______________________________________________ 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/
