Re: deterministic io throughput in multipath

[Muneendra Kumar M <mmandala@Brocade.com>]

Hi Ben,

Thanks for the reply.
I will look into this parameters will do the internal testing and let you know the results.

Regards,
Muneendra.

-----Original Message-----
From: Benjamin Marzinski [mailto:bmarzins@redhat.com] 
Sent: Wednesday, December 21, 2016 9:40 PM
To: Muneendra Kumar M <mmandala@Brocade.com>
Cc: dm-devel@redhat.com
Subject: Re: [dm-devel] deterministic io throughput in multipath

Have you looked into the delay_watch_checks and delay_wait_checks configuration parameters?  The idea behind them is to minimize the use of paths that are intermittently failing.

-Ben

On Mon, Dec 19, 2016 at 11:50:36AM +0000, Muneendra Kumar M wrote:
>    Customers using Linux host (mostly RHEL host) using a SAN network for
>    block storage, complain the Linux multipath stack is not resilient to
>    handle non-deterministic storage network behaviors. This has caused many
>    customer move away to non-linux based servers. The intent of the below
>    patch and the prevailing issues are given below. With the below design we
>    are seeing the Linux multipath stack becoming resilient to such network
>    issues. We hope by getting this patch accepted will help in more Linux
>    server adoption that use SAN network.
> 
>    I have already sent the design details to the community in a different
>    mail chain and the details are available in the below link.
> 
>    [1]https://urldefense.proofpoint.com/v2/url?u=https-3A__www.redhat.com_archives_dm-2Ddevel_2016-2DDecember_msg00122.html&d=DgIDAw&c=IL_XqQWOjubgfqINi2jTzg&r=E3ftc47B6BGtZ4fVaYvkuv19wKvC_Mc6nhXaA1sBIP0&m=vfwpVp6e1KXtRA0ctwHYJ7cDmPsLi2C1L9pox7uexsY&s=q5OI-lfefNC2CHKmyUkokgiyiPo_Uj7MRu52hG3MKzM&e= .
> 
>    Can you please go through the design and send the comments to us.
> 
>     
> 
>    Regards,
> 
>    Muneendra.
> 
>     
> 
>     
> 
> References
> 
>    Visible links
>    1. 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.redhat.com_ar
> chives_dm-2Ddevel_2016-2DDecember_msg00122.html&d=DgIDAw&c=IL_XqQWOjub
> gfqINi2jTzg&r=E3ftc47B6BGtZ4fVaYvkuv19wKvC_Mc6nhXaA1sBIP0&m=vfwpVp6e1K
> XtRA0ctwHYJ7cDmPsLi2C1L9pox7uexsY&s=q5OI-lfefNC2CHKmyUkokgiyiPo_Uj7MRu
> 52hG3MKzM&e=

> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.redhat.com_ma
> ilman_listinfo_dm-2Ddevel&d=DgIDAw&c=IL_XqQWOjubgfqINi2jTzg&r=E3ftc47B6BGtZ4fVaYvkuv19wKvC_Mc6nhXaA1sBIP0&m=vfwpVp6e1KXtRA0ctwHYJ7cDmPsLi2C1L9pox7uexsY&s=UyE46dXOrNTbPz_TVGtpoHl3J3h_n0uYhI4TI-PgyWg&e=