On Tuesday 06 July 2010 06:16:55 Bart Coninckx wrote: > On Monday 05 July 2010 20:58:30 Christophe Varoqui wrote: > > On lun., 2010-07-05 at 20:37 +0200, Bart Coninckx wrote: > > > Hi, > > > > > > I would like to run my ideas by this list about multipathing and the > > > results as far as storage speed is concerned. > > > > > > I'm using multipathing to two iSCSI targets pointing to the same > > > storage. It was my understanding that this provides for network path > > > redundancy (and it does, I tested this) but also for added speed. > > > I did some tests with Bonnie++ however while both paths were active and > > > one path was down and the results are basically the same. > > > > > > Am I assuming wrong things? Or have I configured things wrong? > > > > can you also include a 'multipath -l' output and sketch the > > hba/switch/controller physical connections ? > > > > thanks, > > Sure, > > xen3:~ # multipath -l > lx03 (1494554000000000000000000010000000000000002000000) dm-3 > IET,VIRTUAL-DISK [size=10G][features=1 queue_if_no_path][hwhandler=0] > \_ round-robin 0 [prio=-2][active] > \_ 2:0:0:0 sdc 8:32 [active][undef] > \_ 1:0:0:0 sdb 8:16 [active][undef] > ws033 (1494554000000000000000000010000000100000002000000) dm-2 IET,VIRTUAL- > DISK > [size=15G][features=1 queue_if_no_path][hwhandler=0] > \_ round-robin 0 [prio=-2][active] > \_ 2:0:0:1 sde 8:64 [active][undef] > \_ 1:0:0:1 sdd 8:48 [active][undef] > ms01 (1494554000000000000000000010000000200000002000000) dm-1 > IET,VIRTUAL-DISK [size=40G][features=1 queue_if_no_path][hwhandler=0] > \_ round-robin 0 [prio=-2][active] > \_ 1:0:0:2 sdf 8:80 [active][undef] > \_ 2:0:0:2 sdg 8:96 [active][undef] > > I have two Gigabit NICs in this server each running over a separate switch > to a separate gigabit NIC with a unique IP address on the storage IET > iSCSI target. > > Is this sufficient info? > > Thx, > > Bart > > -- > dm-devel mailing list > dm-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/dm-devel > Hi all, to show my point, these are the results of running bonnie++ locally on the storage - the values I look at are Block values in K/sec in both sequential output (writing) and sequential input (reading): Version 1.03e ------Sequential Output------ --Sequential Input- -- Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- -- Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP iscsi3 8G 69351 96 116112 32 41128 10 57874 82 107721 16 418.2 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- - Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 4533 99 +++++ +++ +++++ +++ 4395 99 +++++ +++ 17122 99 iscsi3,8G,69351,96,116112,32,41128,10,57874,82,107721,16,418.2,0,16,4533,99, +++++,+++,+++++,+++,4395,99,+++++,+++,17122,99 So were are hitting roughly 110 MB/sec locally on the storage server. Now these are the results do doing the same over multipath with two paths enabled: Version 1.03e ------Sequential Output------ --Sequential Input- -- Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- -- Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP xen3 8G 63953 92 100525 26 26885 2 41957 55 68184 2 357.9 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- - Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 5326 98 +++++ +++ +++++ +++ 5333 97 +++++ +++ 17179 100 xen3,8G,63953,92,100525,26,26885,2,41957,55,68184,2,357.9,0,16,5326,98,+++++, +++,+++++,+++,5333,97,+++++,+++,17179,100 You can see we hit somewhat less, probably due to TCP overhead (though this should cut things with 30%). Now the same with one path down: Version 1.03e ------Sequential Output------ --Sequential Input- -- Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- -- Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP xen3 8G 33214 46 113811 29 27917 1 44474 58 68812 2 362.8 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- - Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 5294 98 +++++ +++ +++++ +++ 5337 97 +++++ +++ 17183 99 xen3,8G,33214,46,113811,29,27917,1,44474,58,68812,2,362.8,0,16,5294,98,+++++, +++,+++++,+++,5337,97,+++++,+++,17183,99 As you can see, roughly the same K/sec for both output and input. Actually writing is even faster with one path down! Can anyone make sense of these values? thx! B. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
