Yao Wei [njus...@gmail.com] wrote:
> The main purpose of my using iscsi is to implement remote disk
> copying.
> When I installed iscsi-target on Dell machine and using the whole disk
> to be the target:
>  Lun 0 Path=/dev/sda,Type=fileio
> then on my ibm x3550 machine (with two NICs) , I first configure  NIC1
> and NIC2 with different MAC addresses in /etc/iscsi/ifaces/iface0 and
> iface1, and then I  use iscsiadm -m discovery -t st -p ip -I iface1 -l
> to discovery and login the iscsi discovery.
> To test the  write and read speed of remote disk, I first use hdparm -
> t /dev/sdb to get the speed of timing buffered disk reads: less than
> 10MB/sec.
> More, I directly using dd if=/dev/sdb of=/home/my.dd ibs=32k to copy
> the whole disk, it consume very much time, as slow as 10 MB/s.
> Later, I let IBM x3550 machine to be the iscsi-target, and Dell
> machine to be the initiator, and do the procedure as above, I found
> that the speed of hdparm command can obtain about 80-100 MB/s, and
> also the command of dd a 40GB hard disk can be finished within
> 15 minutes (about 50 MB/s).

The speed here you got is more than twice of the other path, so I
imagine the bottleneck is not the network speed. It is probably your
disk speed on Dell that is limiting you resulting in poor 10MB/sec
performance. What does 'hdparm' say on the same disk from the Dell

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