Re: RAID-1 to RAID-5 online migration?
On Mon, 13 Sep 2004 16:39, Andrew Miehs <andrew@2sheds.de> wrote:
> Ummm... Bit confused here, but RAID 1 is not faster, than a single disk.
RAID-1 in the strict definition has two disks with the same data. In the
modern loose definition it means two or more disks with the same data (maybe
3 disks).
There is an option of whether reads go to all disks in a RAID-1 set or to just
one disk. Some OSs (such as AIX) make this a tunable. In Linux there is no
option, reads go to one disk.
So if two programs make read requests at the same time with a software RAID-1
on Linux then (ideally) each disk will receive one request and the result
will be that the two requests are satisfied in less time than it would take
on a single disk.
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