Dne 10.9.2011 00:28, Bill Davidsen napsal(a): > Pavel Hofman wrote: >> Dne 16.8.2011 01:55, NeilBrown napsal(a): >> >>> Also, it doesn't have to be a linear stack. It could be a binary tree >>> though that might take a little more care to construct. >>> >> Since our backup server being a critical resource needs redundancy >> itself, we are running two degraded RAID1s in parallel, using two >> internal drives. The two alternating external drives plug into the >> corresponding bitmap-enabled RAID1. >> > > I wonder if you could use a four device raid1 here, two drives > permanently installed and two being added one at a time to the array. > That gives you internal redundancy and recent backups as well. I am not sure you could employ the write-intent bitmap then. And the bitmap makes the backup considerably faster. > > I'm still a bit puzzled about the idea of rsync being too much CPU > overhead, but I'll pass on that. The issue I have had with raid1 for a > backup is that the data isn't always in a logical useful state when you > do physical backup. Do thing with scripts and hope you always run the > right one. I am afraid I do not understand exactly what you mean :-) We have a few scripts, but only one is started manually, the rest is taken care of automatically. Pavel. -- 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
