Peter Rabbitson wrote: > Moshe Yudkowsky wrote: >> >> One of the puzzling things about this is that I conceive of RAID10 as >> two RAID1 pairs, with RAID0 on top of to join them into a large drive. >> However, when I use --level=10 to create my md drive, I cannot find >> out which two pairs are the RAID1's: the --detail doesn't give that >> information. Re-reading the md(4) man page, I think I'm badly mistaken >> about RAID10. >> >> Furthermore, since grub cannot find the /boot on the md drive, I >> deduce that RAID10 isn't what the 'net descriptions say it is. In fact, everything matches. For lilo to work, it basically needs a whole filesystem on the same physical drive. It's exactly the case with raid1 (and only). With raid10, half of the filesystem is on one mirror, and another half is on another mirror. Like this: filesystem blocks on raid0 blocks DiskA DiskB 0 0 1 1 2 2 3 3 4 4 5 5 .. (this is (this is the actual what LILO layout) expects) (Difference between raid10 and raid0 is that each of diskA and diskB is in fact composed of two identical devices). If your kernel is located in filesytem blocks number 2 and 3 for example, lilo has to read BOTH halves, but it is not smart enough to figure it out - it can only read everything from a single drive. > It is exactly what the names implies - a new kind of RAID :) The setup > you describe is not RAID10 it is RAID1+0. Raid10 IS RAID1+0 ;) It's just that linux raid10 driver can utilize more.. interesting ways to lay out the data. /mjt - 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
