Re: [RFC][PATCH] Introduce the parameter to limit scsi timeout count

[Takahiro Yasui <tyasui@redhat.com>]

Hi James,

James Bottomley wrote:
> It doesn't really look like a good solution to the problem you're
> describing, particularly if it's just a few isolated arrays.
> 
> The code you propose would certainly catch things like usb devices which
> are known for random timeouts; plus a lot of SCSI/ATA devices suffer
> isolated timeouts because of I/O load.  Global code like this could end
> up offlining them.
> 
> Which arrays are these, and what's the taxonomy of the failure ... if
> TUR succeeds, perhaps there's another command for the arrays we could
> send that would fail or timeout ... or perhaps there's a different way
> they should be recovered.

Thank you for the comments. I believe that this issue is not specific
to a few storages but is a general issue on a HDD storages. Therefore,
I think that adding a max timeout count on each device is one of
solutions to servers which are sensitive to delay.

But I got your point. I will try to find an implementation to not
affect other devices.

Thanks,
---
Takahiro Yasui
Hitachi Computer Products (America), Inc.