[dm-devel] [PATCH]:[multipath-tools] Adding the hwtable for LSI generic rdac storage devices
Moger, Babu
Babu.Moger at lsi.com
Wed Mar 11 14:41:31 UTC 2009
On Fri, 2009-03-06 at 09:38 -0700, Moger, Babu wrote:
> This patch adds the hwtable for LSI rdac generic storage. Also sets the feature pg_init_retries to maximum(50).
>
> Signed-off-by: Babu Moger <babu.moger at lsi.com>
>
> ---
>
> --- multipath-tools/libmultipath/hwtable.c.orig 2009-03-04 14:33:11.000000000 -0600
> +++ multipath-tools/libmultipath/hwtable.c 2009-03-04 14:43:57.000000000 -0600
> @@ -837,6 +837,22 @@ static struct hwentry default_hw[] = {
> .checker_name = RDAC,
> .prio_name = PRIO_RDAC,
> },
> + /* LSI Generic rdac storage */
> + {
> + .vendor = "(LSI|ENGENIO)",
> + .product = "INF-01-00",
> + .getuid = DEFAULT_GETUID,
> + .features = "2 pg_init_retries 50",
> + .hwhandler = "1 rdac",
> + .selector = DEFAULT_SELECTOR,
> + .pgpolicy = GROUP_BY_PRIO,
> + .pgfailback = -FAILBACK_IMMEDIATE,
> + .rr_weight = RR_WEIGHT_NONE,
> + .no_path_retry = 15,
you don't want to use "queue" for no path retry ?
No, We did not want to set it to "queue" by default. Reason is, we know that I/O session will hang in case of all path failure. User will not know why the session is non-responsive, if he is not familiar with this feature. Also, we think this feature (queue) is meant for maintenance or support (like replacing the switch/cable or shutting down the storage for short duration). In these cases user can set to queue on the fly.
Want to mention one more thing. I saw other hwtable table (mostly IBM). They don't set the feature pg_init_retries. In that case it is defaulting to 0. We have seen issues because of this during the failovers. In case of multi-host scenario (more than one host accessing the same storage), we have seen failovers not been able complete in one attempt and resulting I/O failure. I would suggest setting pg_init_retries to maximum by default.
> + .minio = DEFAULT_MINIO,
> + .checker_name = RDAC,
> + .prio_name = PRIO_RDAC,
> + },
> /*
> * EOL
> */
>
>
>
> --
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