[dm-devel] dd slow while reading on multipathing, writing is fast

[Christophe Varoqui]

On mar., 2011-02-08 at 15:44 +0100, bart.coninckx at telenet.be wrote:
> Hi all,
> 
> something peculiar I cannot get my head round.
> I have a setup where a backup server connects to iSCSI LUNs over multipathing.
> While dd-ing to it, I get a spiffing 200 MB/sec, while reading it drops to 70 MB/sec. Local storage where I write the image onto is sufficiently fast.
> 
> Do you think this is multipathing related? I'm running the latest version from source.
> 
please send at least
- kernel version
- multipath tools version
- device map string