Luca Berra wrote: > >Just like the kernel is now able to autodetect and > >autoenable md RAID arrays, are there plans to make > kernel autodetection of md arrays is almost always a > bad idea, it is far better to use mdadm in user space for that. Why is this necessarily so? RAID autodetect seems to avoid a lot of configuration hassles especially when your root partition is involved. Any horror stories to tell? > >lvm do the same? (i.e integrate the functionality > >of vgscan / vgchange -ay,-an into the kernel) > no, it is an user space task, there is no reason to > burden the kernel with this. People have recommended against using an LVM volume for your root partition citing the hassle of a rescue disk as being the main reason. If lvm volume autodetect and enabling were in the kernel, then this would no longer be the case. I have a good reason for wanting my root partition to be a logical volume: this is because I can install my distro directly into it one single big logical volume and only have to worry about how to repartition it later in the game. Being unable to use a logical volume as root partition is very inconvenient because you have to make an early decision regarding which of your top-level directories (i.e. /usr, /home, /var, /opt, /tmp) to turn into logical volumes and which ones to put on physical partitions. Worse, as far as I can tell, you are forced to allocate one logical volume per top-level dir. This means you are unable to share logical volume space among directories for which it makes sense to (e.g. /opt and /usr), thus you might find yourself resizing logical volumes more often than you wish down the line. If lvm were stable and mature enough, and if the claism being made for it as having very low overhead area are accurate, the logical conclusion (no pun intended) would be for people to eventually stop using physical partitions and using volume groups from the get-go. Unless lvm detect/enable functionality were built into the kernel though, you will always have to live with a physical partition holding /boot - the case today with LVM and RAID0, but not RAID1 (from which it is possible to boot directly off of). _______________________________________________ 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/
