If I'm posting to the wrong group, sorry. just point to the RTFM link. This post is about setting up a Debian box with four disks (size should not be important, me thinks), let's assume that a Raid 5 is the correct type for the intended use. Keeping aside LVM and/or layering of md (just for simplicity), and taking into account that /boot, / and maybe other areas should go in a Raid 1 configuration, for booting reliability. I have three questions that perhaps you could help to clarify: 1.- Should the "rest of the disk" be only one partition? I have read that making several partitions and setting several md disks: sd[a..d]2 --> md1 sd[a..d]3 --> md2 sd[a..d]4 --> md3 would help with the rebuild time of each md, which sounds correct. It is also proposed that the md on the outer area of the disk would be faster allowing for better control of performance, assigning faster mds to the more used filesystems. However, and this I don't know, those sda[2..4] are not really different devices (spindles) and reads to one md would conflict (or not?) with reads to the other mds. Setting the whole disk as one partition would prevent any conflict but would take longer to rebuild and files would be spread over the whole area of the disk. I really don't know the internals of md well enough to tell what advantages and problems one setup has over the other. 2.- On the Raid 1: How many sectors to copy? 63? On an update of grub code, core.img could change, which means that the first 63 sectors (to be on the safe side) of the disk which gets the update should be copied to the other 3 disks. Or is it that the md code would mirror sectors 1-62 and only the MBR needs to be manually mirroed? 2.- Is there a recomended way to trigger the said copy of question 2? Where should a call to copy the MBR should be placed? On update-grub? TIA -- Antonio Perez -- 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
