On Tuesday May 25, robin-lists@xxxxxxxxxxxxxx wrote: > Neil Brown wrote: > > > > I often RAID1 a pair of whole devices, partition them into > > root/swap/rest and boot off them (this is using md partitioning code > > which isn't in 2.4, but is in 2.6). There is a problem here that lilo > > thinks it knows all about md arrays. However I figured out how to > > trick it into not realising they are md arrays and it works fine (I > > create a symlink from /dev/MD* -> /dev/md* and only tell lilo about > > /dev/MD*). > > Neil, > > Would you care to elaborate? > > I'm about to build a box with 6 x 250GB SATA disks and am currently > designing the partitioning scheme. > > Could I potentially put in a small IDE disk onto which to install just > enough system to boot and mount a RAID5 array built from the 6 whole disks? > > Presumably you then partition the RAID array, create the filesystems and > mount the partitions as you would a single disk? In this configuration I wouldn't raid whole drives. I would partition each drive into 6 gig root 2 gig swap N-8 gig extra I would raid1 2 or 3 root partitions together and add the rest as hot spares. I would raid1 2 or 3 swap partitions together and add the rest as hot spares. I would raid5 the extra partitions together and put the bulk storage there. If you want a single large root and no extra partitions, I would then make a 1 gig boot and an N-1 gig root on each device, raid1 the boot devices together and put kernels there. raid5 the root devices together and put everything there. swap to a file on the root filesystem. The two situations where I raid together whole devices are: 1/ computers with only two drives - then I mirror and partition. 2/ fileservers where the main storage drives are physically separate in some way, either in a different cage, or in the same cage but a different size (2 smaller drives for boot/root/etc, several larger drives for storage). Then I raid5 all the storage devices together. In between these two (just two drives, and lots of drives) is the several-drives-in-one-case situation, where partitioning and then RAIDing works well. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
