Support for Multipath?

Support for Multipath?

[eric pretorious]

Hello:

Does stgt include support for multipath?
Is there any special configuration required on the target?
How is multipath enabled/disabled/tested in stgt?

--
Eric Pretorious
Portland, OR

RE: Support for Multipath?

[Roi Dayan]

Hi Eric,

Do you mean support for device mapper multipath?
You don’t need anything special. Connect to tgtd from 2 ports and you'll have 2 block devices (if its 1 target and 1 lun).
In the initiator rescan the devices by executing multipath and using "multipath -l" you can see a dm that is over the 2 block devices.

Thanks,
Roi

-----Original Message-----
From: stgt-owner@vger.kernel.org [mailto:stgt-owner@vger.kernel.org] On Behalf Of eric pretorious
Sent: Saturday, December 05, 2015 12:41 AM
To: stgt@vger.kernel.org
Subject: Support for Multipath?

Hello:

Does stgt include support for multipath?
Is there any special configuration required on the target?
How is multipath enabled/disabled/tested in stgt?

--
Eric Pretorious
Portland, OR
--
To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@vger.kernel.org More majordomo info at  http://vger.kernel.org/majordomo-info.html

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Re: Support for Multipath?

[eric pretorious]

> Do you mean support for device mapper multipath?

Yes.

> You don’t need anything special. Connect to tgtd from 2 ports and you'll have 2 block devices (if its 1 target and 1 lun).

Thanks, Roi: That was pretty easy!

Steps to I used to verify... (Initiator is also multi-homed:
172.16.0.2.& 172.16.0.3. Target is *also* multi-homed: 172.16.0.29 &
172.16.0.30.)

> [root@initiator ~]# iscsiadm -m node
> iscsiadm: No records found
>
> [root@initiator ~]# iscsiadm -m discovery --type sendtargets -p 172.16.0.29
> 172.16.0.29:3260,1 iqn.2015-12.com.example.target:One
> 172.16.0.29:3260,1 iqn.2015-12.com.example.target:Two
>
> [root@initiator ~]# iscsiadm -m discovery --type sendtargets -p 172.16.0.30
> 172.16.0.30:3260,1 iqn.2015-12.com.example.target:One
> 172.16.0.30:3260,1 iqn.2015-12.com.example.target:Two
>
> [root@initiator ~]# iscsiadm -m node
> 172.16.0.29:3260,1 iqn.2015-12.com.example.target:One
> 172.16.0.30:3260,1 iqn.2015-12.com.example.target:One
> 172.16.0.29:3260,1 iqn.2015-12.com.example.target:Two
> 172.16.0.30:3260,1 iqn.2015-12.com.example.target:Two
>
> [root@initiator ~]# multipath -ll
>
> [root@initiator ~]# iscsiadm -m node -T iqn.2015-12.com.example.target:One -p 172.16.0.29 -l
> Logging in to [iface: default, target: iqn.2015-12.com.example.target:One, portal: 172.16.0.29,3260] (multiple)
> Login to [iface: default, target: iqn.2015-12.com.example.target:One, portal: 172.16.0.29,3260] successful.
>
> [root@initiator ~]# iscsiadm -m session
> tcp: [3] 172.16.0.29:3260,1 iqn.2015-12.com.example.target:One (non-flash)
>
> [root@initiator ~]# multipath -ll
> 1IET     00010001 dm-2 IET,VIRTUAL-DISK
> size=800M features='0' hwhandler='0' wp=rw
> `-+- policy='round-robin 0' prio=1 status=active
>   `- 5:0:0:1 sdb 8:16 active ready running
>
> [root@initiator ~]# iscsiadm -m node -T iqn.2015-12.com.example.target:One -p 172.16.0.30 -l
> Logging in to [iface: default, target: iqn.2015-12.com.example.target:One, portal: 172.16.0.30,3260] (multiple)
> Login to [iface: default, target: iqn.2015-12.com.example.target:One, portal: 172.16.0.30,3260] successful.
>
> [root@initiator ~]# iscsiadm -m session
> tcp: [3] 172.16.0.29:3260,1 iqn.2015-12.com.example.target:One (non-flash)
> tcp: [4] 172.16.0.30:3260,1 iqn.2015-12.com.example.target:One (non-flash)
>
> [root@initiator ~]# multipath -ll
> 1IET     00010001 dm-2 IET,VIRTUAL-DISK
> size=800M features='0' hwhandler='0' wp=rw
> |-+- policy='round-robin 0' prio=1 status=enabled
> | `- 5:0:0:1 sdb 8:16 active ready running
> `-+- policy='round-robin 0' prio=1 status=active
>   `- 6:0:0:1 sdc 8:32 active ready running

Thanks, again!

Eric Pretorious
Portland, Oregon

On Sun, Dec 6, 2015 at 4:32 AM, Roi Dayan <roid@mellanox.com> wrote:
> Hi Eric,
>
> Do you mean support for device mapper multipath?
> You don’t need anything special. Connect to tgtd from 2 ports and you'll have 2 block devices (if its 1 target and 1 lun).
> In the initiator rescan the devices by executing multipath and using "multipath -l" you can see a dm that is over the 2 block devices.
>
> Thanks,
> Roi
>
> -----Original Message-----
> From: stgt-owner@vger.kernel.org [mailto:stgt-owner@vger.kernel.org] On Behalf Of eric pretorious
> Sent: Saturday, December 05, 2015 12:41 AM
> To: stgt@vger.kernel.org
> Subject: Support for Multipath?
>
> Hello:
>
> Does stgt include support for multipath?
> Is there any special configuration required on the target?
> How is multipath enabled/disabled/tested in stgt?
>
> --
> Eric Pretorious
> Portland, OR
> --
> To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@vger.kernel.org More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please visit http://www.symanteccloud.com ______________________________________________________________________



-- 
Eric Pretorious
+1.530.386.3649

Re: Support for Multipath?

[eric pretorious]

FYI: I found this YouTube video VERY helpful in my quest to understand
and implement stgt & DM-MPIO -
https://www.youtube.com/watch?v=xrLREFSF0uM

HTH,
Eric Pretorious
Portland, OR

On Fri, Dec 4, 2015 at 2:40 PM, eric pretorious <epretorious@gmail.com> wrote:
> Hello:
>
> Does stgt include support for multipath?
> Is there any special configuration required on the target?
> How is multipath enabled/disabled/tested in stgt?
>
> --
> Eric Pretorious
> Portland, OR