I'm building a filer on a limited budget with two sets of SATAII disks, one made of 6x500GB, the other 4x2TB and a recent kernel. I understand that LVM over software RAID is the way to go, but I'm not clear on which of the following two scenarios would be "better" - data availability, flexibility in handling future space expansion and ease of recovery are more important than performance issues for me, but of course I'd like to optimize for both if possible. (ASCII art best viewed with a monospaced font) Scenario A is traditional RAID1 mirroring, letting LVM handling the striping. ________________________________________________ | LVM VG | | _____________ _____________ ____________ | | | LVM PV1 | | LVM PV2 | | LVM PV3 | | | | ___________ | | ___________ | | ___________| | | || RAID1 || || RAID1 || || RAID1 | | | || __ __ || || __ __ || || __ __ | | | || |__| |__| || || |__| |__| || || |__| |__| | | | ||___________|| ||___________|| ||___________| | | |_____________| |_____________| |____________| | |________________________________________________| Scenario B is making use of RAID10 (the mdm-specific one, not generic RAID1+0, probably the ",f2" flavor) to handle the striping, presenting one physical disk to LVM to use as a PV. _______________ | LVM PV = VG | | ___________ | | | RAID10,f2 | | | | __ __ | | | | |__| |__| | | | | __ __ | | | | |__| |__| | | | | __ __ | | | | |__| |__| | | | |___________| | |_______________| If I should go with A, then my next question is - does LVM automatically optimize the striping for performance, or should I "help" it by created multiple PVs by slicing the disks up into partitions? If the latter, then that seems to sacrifice a lot of A's simplicity and perhaps greater ease of data recovery. Any and all feedback welcome, TIA. -- 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
