Teaming of paths

Hi all,

In a network environment it's possible to team/trunk multiple lines between
switches and/or hosts to one virtual single connection boosting throughput.
Is this also possible in a san environment?

I ask this because I've recently obtained a Dell Powervault 660F wich is
configurable with two controllers (raid) thus giving me two connections.
Would be nice if I can double the bandwidth.

Marcel

"Marcel" wrote in :

In a network environment it's possible to team/trunk multiple lines
between switches and/or hosts to one virtual single connection
boosting throughput. Is this also possible in a san environment?

I ask this because I've recently obtained a Dell Powervault 660F wich
is configurable with two controllers (raid) thus giving me two
connections. Would be nice if I can double the bandwidth.

As an end-to-end solution, you'd use multipathing software like powerpath,
veritas dmp, securepath or whatever else you feel like. Between switches
(and yes, i know that wasn't really the question), you can use ISL trunking
which, depending on the switch vendor, behaves in much the same way as
etherchannel on a LAN. On Brocade, one trunk link can move twice the
traffic, even if only one session is running, whereas McData will only do
load balancing by moving several sessions back and forth between the links.

--
/Jesper Monsted

Marcel wrote:
Hi all,

In a network environment it's possible to team/trunk multiple lines between
switches and/or hosts to one virtual single connection boosting throughput.
Is this also possible in a san environment?


between switches, yes.


I ask this because I've recently obtained a Dell Powervault 660F wich is
configurable with two controllers (raid) thus giving me two connections.
Would be nice if I can double the bandwidth.


create 2 luns, bind them to separate controllers and create an raid0
volume in host.

toomas
--
It is now 10 p.m. Do you know where Henry Kissinger is?
-- Elizabeth Carpenter

"Jesper Monsted" schreef in bericht
4.163...
"Marcel" wrote in :

In a network environment it's possible to team/trunk multiple lines
between switches and/or hosts to one virtual single connection
boosting throughput. Is this also possible in a san environment?

I ask this because I've recently obtained a Dell Powervault 660F wich
is configurable with two controllers (raid) thus giving me two
connections. Would be nice if I can double the bandwidth.

As an end-to-end solution, you'd use multipathing software like powerpath,
veritas dmp, securepath or whatever else you feel like. Between switches
(and yes, i know that wasn't really the question), you can use ISL
trunking
which, depending on the switch vendor, behaves in much the same way as
etherchannel on a LAN. On Brocade, one trunk link can move twice the
traffic, even if only one session is running, whereas McData will only do
load balancing by moving several sessions back and forth between the
links.

--
/Jesper Monsted

Does the general multhipathing software use some sort of loadbalancing
between the two or more paths?

Marcel

"Toomas Soome" schreef in bericht
...
Marcel wrote:
Hi all,

In a network environment it's possible to team/trunk multiple lines
between
switches and/or hosts to one virtual single connection boosting
throughput.
Is this also possible in a san environment?


between switches, yes.


There is no vendor that has some sort of option to combine two line to one
switch?


I ask this because I've recently obtained a Dell Powervault 660F wich is
configurable with two controllers (raid) thus giving me two connections.
Would be nice if I can double the bandwidth.


create 2 luns, bind them to separate controllers and create an raid0
volume in host.

toomas
--
It is now 10 p.m. Do you know where Henry Kissinger is?
-- Elizabeth Carpenter

That certainly is interesting when using only a few host and you would do
this on all of them. Not when you've got a few more and some of them only
has one single connection. Besides of that, I want to double the bandwidth
to the switch from the disk array, single throughput should be sufficient
for the hosts.

I think it's smarter to give each seperate port on the powervault a
connection to a different switch and equally share the hosts. Or I can use
one switch and create two zones, one powervault port per zone and again an
equal share of hosts among the zones. Any thaughts on this?

Marcel Wrote:
"
Does the general multhipathing software use some sort of loadbalancing
between the two or more paths?

Marcel


This really depends on the DMP Software. Some uses SCSI Timeouts in
order to detect problems with the link or connection and move new
connections to the other path. Some also provide some round robin
functionality, but Round Robin is just the "lowest possible feature of
loadbalacing" (IMHO).
As far as I know (please tell me I'm wrong and FC Vendors learned from
networking vendors), there is no DMP Software available which really
does loadbalacing based on the current load of the links into the
fabric.

/dev/null


--
/dev/null


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Jesper Monsted wrote:

Between switches
(and yes, i know that wasn't really the question), you can use ISL
trunking which, depending on the switch vendor, behaves in much the same
way as etherchannel on a LAN.

Does it work that way with Cisco switches? A "trunk" circuit carries all
(or a specified list of) VLANs. If you've two "trunk" circuits between a
pair of switches, does that it is trunked automatically cause load sharing?

Is this only ISL, or will .1q trunks behave the same?

- Andrew

"Marcel" wrote in :
Does the general multhipathing software use some sort of loadbalancing
between the two or more paths?

Some of it does, yes.


--
/Jesper Monsted

/dev/null wrote in
:

This really depends on the DMP Software. Some uses SCSI Timeouts in
order to detect problems with the link or connection and move new
connections to the other path. Some also provide some round robin
functionality, but Round Robin is just the "lowest possible feature of
loadbalacing" (IMHO).
As far as I know (please tell me I'm wrong and FC Vendors learned from
networking vendors), there is no DMP Software available which really
does loadbalacing based on the current load of the links into the
fabric.

You're wrong

Powerpath uses latency and other factors to balance load across several
paths to symmetrix or clariion arrays.

--
/Jesper Monsted

Andrew Gideon wrote in
gonline.com:

Between switches
(and yes, i know that wasn't really the question), you can use ISL
trunking which, depending on the switch vendor, behaves in much the
same way as etherchannel on a LAN.

Does it work that way with Cisco switches? A "trunk" circuit carries
all (or a specified list of) VLANs. If you've two "trunk" circuits
between a pair of switches, does that it is trunked automatically
cause load sharing?

Is this only ISL, or will .1q trunks behave the same?

In FC, it's called ISL trunking, but it's basically the same as Cisco
etherchannel (on McData - it's somewhat more intelligent on Brocade). If
you plug in two ISLs between two switches, they will (with some
limitations, at least on Brocade) automatically trunk the link. They use
two quite different methods, but accomplish mostly the same.


--
/Jesper Monsted