On Sun, 14 Mar 2010 00:31:01 +0300 "Majed B." <majedb@xxxxxxxxx> wrote: > Neil, > > Since when was this possible? I always thought that it had to have an > even number of disks. md has never imposed a 2-drive restriction on raid1. That would be fairly pointless. Requiring an even number of devices would also be pointless. The term "mirror" is possibly a cause of confusion as it suggests an original and a copy. It also suggests that the copy is reflected in some way. Neither of these are true. RAID1 stores multiple copies of the same data. All copies are equal. You can have as many or as few of them as you like. 1, 2, 3, 4, .... NeilBrown > > On Sun, Mar 14, 2010 at 12:26 AM, Neil Brown <neilb@xxxxxxx> wrote: > > On Sat, 13 Mar 2010 16:06:38 -0500 > > Carlos Mennens <carloswill@xxxxxxxxx> wrote: > > > >> I was told by my distributions Wiki page that Grub doesn't support > >> RAID 5 or RAID 6 so I would need to create a volume with three disks > >> and set the level to RAID 1: > >> > >> # mdadm --create /dev/md1 --level=1 --raid-devices=3 /dev/sda1 > >> /dev/sdb1 /dev/sdc1 --spare-devices=1 /dev/sdd1 > >> > >> Is this possible to mirror three identical drive partitions? I was > >> talking to some co-workers and was told that I could only pair two > >> drives on RAID 1. > > > > Your co-workers are wrong, at least for md raid. With md, a RAID1 can have > > any number of devices from 1 upwards - the limit varies in different > > situations but is at least 28. > > > > Try it and see. > > > > NeilBrown > > > >> > >> Can anyone please help me understand this? > >> -- > >> 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 > > > > -- > > 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 > > > > > -- 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
