On Thursday September 5, mjt@tls.msk.ru wrote: > Derek Vadala wrote: > > > > On Wed, 4 Sep 2002, Arne Wiebalck wrote: > > > > > is it possible to have partitions on a RAID device? > > > > > > [...] > > > > > > Anything I am missing here? > > > > You first need to patch your kernel so that the md driver and md devices > > support partitioning. Check out > > http://cgi.cse.unsw.edu.au/~neilb/patches/linux-stable/ for the patches. > > Hmm, interesting. What's those patches are for? What's their status? > Are they just experiments, proof-of-concept, or intended for general > use? Are there any interdependances of the set of 5 md-related patches > for 2.4.19? Some more information on this all? Discussions? Official > 2.4/2.5 status of this work? Relation with e.g. LVM? Iteraction with > devfs for mdp? Device nodes assignment (i.e. what will become mpa, mpb > etc when one have md0, md1 etc)? (There are quite a few aspects mentioned > on the above page, mostly nfs-, ext[23]- and md-related stuff, but this is > linux-raid list :) > > Errm, so many question... ;) State: I use them in production on most of my servers. I like to mirror two whole devices together, and use that as the system disk. I parition it for a root, a swap, and an other-stuff partitions. Lilo needs a bit of coaxing to make it work with partitioned raid. Dependancies: probably. I should sort them out and maybe submit bits to Marcelo if I ever find a minute. I'd kind-of like to ge partitioning into 2.5 before I submit it for 2.4 though. LVM: Independant, thought can provide vaguely similar function. devfs: works fine. try it and see. device nodes: minors 0..15 are /dev/md/d0, /dev/md/d0p1, /dev/md/d0p2, ... /dev/md/d0p15 minors 16..31 are /dev/md/d1, /dev/md/d1p1, /dev/md/d1p2, ... /dev/md/d1p15 /dev/md/d0 is the same as /dev/md0 /dev/md/d1 is the same as /dev/md1 > > BTW, still don't know which is "better" -- have several md arrays for every > filesystem/whatether, or have one md array and split it using e.g. lvm or > using this mdp method? (Two different point of view: system resource usage > should be less for one large md array, but will this one large array handle > load as effective as several independant ones?) Depends what you want to do. As I said, I use a partitions raid1 part of drives for some servers. For others (where I want a bit more disk space and so have extra drives) I partition each drive, into root, swap and rest. All the roots are raid1 together. All the swaps are raid1 together All the rest are raid5 together. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
