[linux-lvm] lvm lowers transfer rate

[William Blunn]

> I have 4 fiber channel disks, on which I intend to build a logical
> volume using lvm. Before creating the logical volume, I run an I/O
> test on the disks, which revealed that the disks each would do
> 10MBytes/sec I/Os.
>
> However, when I create a logical volume, spanning all 4 disks using
> RAID0, I realize that the transfer rate now drops. Instead
> (10 * 4)MB/s, I get something close to 30MB/s. Am I doing something
> wrong?!?

10 MB/s ?

How are you measuring your data transfer rate?

Measured using "hdparm -t", a single Maxtor D740X IDE drive
(80GB = GBP£72.00 or USD$113) will shift about 39 MB/s.

Bill

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