All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH 0/3] multipath-tools: add new devices to hwtable
@ 2025-09-10 19:41 Xose Vazquez Perez
  2025-09-10 19:41 ` [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure " Xose Vazquez Perez
                   ` (2 more replies)
  0 siblings, 3 replies; 11+ messages in thread
From: Xose Vazquez Perez @ 2025-09-10 19:41 UTC (permalink / raw)
  Cc: Xose Vazquez Perez, Martin Wilck, Benjamin Marzinski,
	Christophe Varoqui, DM_DEVEL-ML

Xose Vazquez Perez (3):
 multipath-tools: add Acronis Cyber Infrastructure to hwtable
 multipath-tools: add EqualLogic PS to hwtable
 multipath-tools: add QSAN to hwtable

 libmultipath/hwtable.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

Cc: Martin Wilck <mwilck@suse.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
-- 
2.51.0


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure to hwtable
  2025-09-10 19:41 [PATCH 0/3] multipath-tools: add new devices to hwtable Xose Vazquez Perez
@ 2025-09-10 19:41 ` Xose Vazquez Perez
  2025-09-11 17:56   ` Benjamin Marzinski
  2025-09-10 19:41 ` [PATCH 2/3] multipath-tools: add EqualLogic PS " Xose Vazquez Perez
  2025-09-10 19:41 ` [PATCH 3/3] multipath-tools: add QSAN " Xose Vazquez Perez
  2 siblings, 1 reply; 11+ messages in thread
From: Xose Vazquez Perez @ 2025-09-10 19:41 UTC (permalink / raw)
  Cc: Xose Vazquez Perez, Martin Wilck, Benjamin Marzinski,
	Christophe Varoqui, DM_DEVEL-ML

Source: https://dl.acronis.com/u/software-defined/html/AcronisCyberInfrastructure_3_5_users_guide_en-US/accessing-iscsi/accessing-iscsi-targets-from-linux.html

Cc: Martin Wilck <mwilck@suse.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
---
 libmultipath/hwtable.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
index 1a78c36d..12e10577 100644
--- a/libmultipath/hwtable.c
+++ b/libmultipath/hwtable.c
@@ -1371,6 +1371,21 @@ static struct hwentry default_hw[] = {
 		.pgpolicy      = GROUP_BY_SERIAL,
 		.no_path_retry = 30,
 	},
+	/*
+	 * Acronis
+	 */
+	{
+		// Cyber Infrastructure
+		.vendor        = "VSTORAGE",
+		.product       = "VSTOR-DISK",
+		.prio_name     = PRIO_ALUA,
+		.pgpolicy      = GROUP_BY_NODE_NAME,
+		.detect_prio   = DETECT_PRIO_OFF,
+		.features      = "2 pg_init_retries 50",
+		.pgfailback    = -FAILBACK_FOLLOWOVER,
+		.flush_on_last_del = FLUSH_ALWAYS,
+		.no_path_retry = NO_PATH_RETRY_QUEUE,
+	},
 	/*
 	 * EOL
 	 */
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH 2/3] multipath-tools: add EqualLogic PS to hwtable
  2025-09-10 19:41 [PATCH 0/3] multipath-tools: add new devices to hwtable Xose Vazquez Perez
  2025-09-10 19:41 ` [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure " Xose Vazquez Perez
@ 2025-09-10 19:41 ` Xose Vazquez Perez
  2025-09-11 17:57   ` Benjamin Marzinski
  2025-09-10 19:41 ` [PATCH 3/3] multipath-tools: add QSAN " Xose Vazquez Perez
  2 siblings, 1 reply; 11+ messages in thread
From: Xose Vazquez Perez @ 2025-09-10 19:41 UTC (permalink / raw)
  Cc: Xose Vazquez Perez, Martin Wilck, Benjamin Marzinski,
	Christophe Varoqui, DM_DEVEL-ML

Source: https://dl.dell.com/manuals/all-products/esuprt_software/esuprt_it_ops_datcentr_mgmt/s-solution-resources_white-papers30_en-us.pdf

Cc: Martin Wilck <mwilck@suse.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
---
 libmultipath/hwtable.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
index 12e10577..392131a3 100644
--- a/libmultipath/hwtable.c
+++ b/libmultipath/hwtable.c
@@ -408,6 +408,13 @@ static struct hwentry default_hw[] = {
 		.prio_name     = PRIO_ALUA,
 		.pgfailback    = -FAILBACK_IMMEDIATE,
 	},
+	{
+		// EqualLogic PS Series
+		.vendor        = "EQLOGIC",
+		.product       = "100E-00",
+		.pgpolicy      = MULTIBUS,
+		.no_path_retry = 30,
+	},
 	/*
 	 * Fujitsu
 	 */
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH 3/3] multipath-tools: add QSAN to hwtable
  2025-09-10 19:41 [PATCH 0/3] multipath-tools: add new devices to hwtable Xose Vazquez Perez
  2025-09-10 19:41 ` [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure " Xose Vazquez Perez
  2025-09-10 19:41 ` [PATCH 2/3] multipath-tools: add EqualLogic PS " Xose Vazquez Perez
@ 2025-09-10 19:41 ` Xose Vazquez Perez
  2025-09-11 17:57   ` Benjamin Marzinski
  2 siblings, 1 reply; 11+ messages in thread
From: Xose Vazquez Perez @ 2025-09-10 19:41 UTC (permalink / raw)
  Cc: Xose Vazquez Perez, Martin Wilck, Benjamin Marzinski,
	Christophe Varoqui, DM_DEVEL-ML

Source #13/15: https://www.qsan.com/data/dl_files/qs_wp_iSCSI-MPIO-in-Linux%20(en).pdf

Cc: Martin Wilck <mwilck@suse.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
---
 libmultipath/hwtable.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
index 80e76fed..d9723f87 100644
--- a/libmultipath/hwtable.c
+++ b/libmultipath/hwtable.c
@@ -1393,6 +1393,18 @@ static struct hwentry default_hw[] = {
 		.flush_on_last_del = FLUSH_ALWAYS,
 		.no_path_retry = NO_PATH_RETRY_QUEUE,
 	},
+	/*
+	 * QSAN
+	 */
+	{
+		// XF / XCubeFAS / XCubeSAN / XN / XCubeNXT Series
+		.vendor        = "^Qsan",
+		.product       = ".*",
+		.pgpolicy      = GROUP_BY_PRIO,
+		.pgfailback    = -FAILBACK_IMMEDIATE,
+		.no_path_retry = 30,
+		.prio_args     = "exclusive_pref_bit",
+	},
 	/*
 	 * EOL
 	 */
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* Re: [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure to hwtable
  2025-09-10 19:41 ` [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure " Xose Vazquez Perez
@ 2025-09-11 17:56   ` Benjamin Marzinski
  2025-09-18 11:08     ` Xose Vazquez Perez
  2025-09-22 18:38     ` Martin Wilck
  0 siblings, 2 replies; 11+ messages in thread
From: Benjamin Marzinski @ 2025-09-11 17:56 UTC (permalink / raw)
  To: Xose Vazquez Perez; +Cc: Martin Wilck, Christophe Varoqui, DM_DEVEL-ML

On Wed, Sep 10, 2025 at 09:41:57PM +0200, Xose Vazquez Perez wrote:
> Source: https://dl.acronis.com/u/software-defined/html/AcronisCyberInfrastructure_3_5_users_guide_en-US/accessing-iscsi/accessing-iscsi-targets-from-linux.html
> 
> Cc: Martin Wilck <mwilck@suse.com>
> Cc: Benjamin Marzinski <bmarzins@redhat.com>
> Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
> Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
> Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
> ---
>  libmultipath/hwtable.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
> index 1a78c36d..12e10577 100644
> --- a/libmultipath/hwtable.c
> +++ b/libmultipath/hwtable.c
> @@ -1371,6 +1371,21 @@ static struct hwentry default_hw[] = {
>  		.pgpolicy      = GROUP_BY_SERIAL,
>  		.no_path_retry = 30,
>  	},
> +	/*
> +	 * Acronis
> +	 */
> +	{
> +		// Cyber Infrastructure
> +		.vendor        = "VSTORAGE",
> +		.product       = "VSTOR-DISK",
> +		.prio_name     = PRIO_ALUA,
> +		.pgpolicy      = GROUP_BY_NODE_NAME,
> +		.detect_prio   = DETECT_PRIO_OFF,
> +		.features      = "2 pg_init_retries 50",
> +		.pgfailback    = -FAILBACK_FOLLOWOVER,

I'm not sure about the pgfailback setting. the FAILBACK_FOLLOWOVER mode
is not something that is really needed for a specific array type. It
works like FAILOVER_IMMEDIATE, but it's designed to work so that if
multiple nodes are using the same multipath device, and one of them
loses access to the highest priority pathgroup but the others don't,
multipath won't keep switching pathgroups back and forth. The nodes that
can see the higher priority pathgroup won't automatically switch back to
it, since they weren't the ones that switched away from it. So the
setting is more for a specific use case, and not a specific array type.

On the other hand, it is what the vendor tested, and with a single
machine accessing the multipath device, you usually only switch away
from the highest priority pathgroup because you lost access to all the
paths in it. So it usually won't get stuck on a lower priority pathgroup
while a higher priority one is usable, although that could happen. 

Thoughts?

-Ben

> +		.flush_on_last_del = FLUSH_ALWAYS,
> +		.no_path_retry = NO_PATH_RETRY_QUEUE,
> +	},
>  	/*
>  	 * EOL
>  	 */
> -- 
> 2.51.0


^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 2/3] multipath-tools: add EqualLogic PS to hwtable
  2025-09-10 19:41 ` [PATCH 2/3] multipath-tools: add EqualLogic PS " Xose Vazquez Perez
@ 2025-09-11 17:57   ` Benjamin Marzinski
  0 siblings, 0 replies; 11+ messages in thread
From: Benjamin Marzinski @ 2025-09-11 17:57 UTC (permalink / raw)
  To: Xose Vazquez Perez; +Cc: Martin Wilck, Christophe Varoqui, DM_DEVEL-ML

On Wed, Sep 10, 2025 at 09:41:58PM +0200, Xose Vazquez Perez wrote:
> Source: https://dl.dell.com/manuals/all-products/esuprt_software/esuprt_it_ops_datcentr_mgmt/s-solution-resources_white-papers30_en-us.pdf
> 
> Cc: Martin Wilck <mwilck@suse.com>
> Cc: Benjamin Marzinski <bmarzins@redhat.com>
> Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
> Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
> Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
> ---
>  libmultipath/hwtable.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
> index 12e10577..392131a3 100644
> --- a/libmultipath/hwtable.c
> +++ b/libmultipath/hwtable.c
> @@ -408,6 +408,13 @@ static struct hwentry default_hw[] = {
>  		.prio_name     = PRIO_ALUA,
>  		.pgfailback    = -FAILBACK_IMMEDIATE,
>  	},
> +	{
> +		// EqualLogic PS Series
> +		.vendor        = "EQLOGIC",
> +		.product       = "100E-00",
> +		.pgpolicy      = MULTIBUS,
> +		.no_path_retry = 30,
> +	},
>  	/*
>  	 * Fujitsu
>  	 */
> -- 
> 2.51.0


^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 3/3] multipath-tools: add QSAN to hwtable
  2025-09-10 19:41 ` [PATCH 3/3] multipath-tools: add QSAN " Xose Vazquez Perez
@ 2025-09-11 17:57   ` Benjamin Marzinski
  0 siblings, 0 replies; 11+ messages in thread
From: Benjamin Marzinski @ 2025-09-11 17:57 UTC (permalink / raw)
  To: Xose Vazquez Perez; +Cc: Martin Wilck, Christophe Varoqui, DM_DEVEL-ML

On Wed, Sep 10, 2025 at 09:41:59PM +0200, Xose Vazquez Perez wrote:
> Source #13/15: https://www.qsan.com/data/dl_files/qs_wp_iSCSI-MPIO-in-Linux%20(en).pdf
> 
> Cc: Martin Wilck <mwilck@suse.com>
> Cc: Benjamin Marzinski <bmarzins@redhat.com>
> Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
> Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
> Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
> ---
>  libmultipath/hwtable.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
> index 80e76fed..d9723f87 100644
> --- a/libmultipath/hwtable.c
> +++ b/libmultipath/hwtable.c
> @@ -1393,6 +1393,18 @@ static struct hwentry default_hw[] = {
>  		.flush_on_last_del = FLUSH_ALWAYS,
>  		.no_path_retry = NO_PATH_RETRY_QUEUE,
>  	},
> +	/*
> +	 * QSAN
> +	 */
> +	{
> +		// XF / XCubeFAS / XCubeSAN / XN / XCubeNXT Series
> +		.vendor        = "^Qsan",
> +		.product       = ".*",
> +		.pgpolicy      = GROUP_BY_PRIO,
> +		.pgfailback    = -FAILBACK_IMMEDIATE,
> +		.no_path_retry = 30,
> +		.prio_args     = "exclusive_pref_bit",
> +	},
>  	/*
>  	 * EOL
>  	 */
> -- 
> 2.51.0


^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure to hwtable
  2025-09-11 17:56   ` Benjamin Marzinski
@ 2025-09-18 11:08     ` Xose Vazquez Perez
  2025-09-22 18:38     ` Martin Wilck
  1 sibling, 0 replies; 11+ messages in thread
From: Xose Vazquez Perez @ 2025-09-18 11:08 UTC (permalink / raw)
  To: Benjamin Marzinski; +Cc: Martin Wilck, Christophe Varoqui, DM_DEVEL-ML

On 9/11/25 7:56 PM, Benjamin Marzinski wrote:

> On Wed, Sep 10, 2025 at 09:41:57PM +0200, Xose Vazquez Perez wrote:
>> Source: https://dl.acronis.com/u/software-defined/html/AcronisCyberInfrastructure_3_5_users_guide_en-US/accessing-iscsi/accessing-iscsi-targets-from-linux.html
>>
>> Cc: Martin Wilck <mwilck@suse.com>
>> Cc: Benjamin Marzinski <bmarzins@redhat.com>
>> Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
>> Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
>> Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
>> ---
>>   libmultipath/hwtable.c | 15 +++++++++++++++
>>   1 file changed, 15 insertions(+)
>>
>> diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
>> index 1a78c36d..12e10577 100644
>> --- a/libmultipath/hwtable.c
>> +++ b/libmultipath/hwtable.c
>> @@ -1371,6 +1371,21 @@ static struct hwentry default_hw[] = {
>>   		.pgpolicy      = GROUP_BY_SERIAL,
>>   		.no_path_retry = 30,
>>   	},
>> +	/*
>> +	 * Acronis
>> +	 */
>> +	{
>> +		// Cyber Infrastructure
>> +		.vendor        = "VSTORAGE",
>> +		.product       = "VSTOR-DISK",
>> +		.prio_name     = PRIO_ALUA,
>> +		.pgpolicy      = GROUP_BY_NODE_NAME,
>> +		.detect_prio   = DETECT_PRIO_OFF,
>> +		.features      = "2 pg_init_retries 50",
>> +		.pgfailback    = -FAILBACK_FOLLOWOVER,
> 
> I'm not sure about the pgfailback setting. the FAILBACK_FOLLOWOVER mode
> is not something that is really needed for a specific array type. It
> works like FAILOVER_IMMEDIATE, but it's designed to work so that if
> multiple nodes are using the same multipath device, and one of them
> loses access to the highest priority pathgroup but the others don't,
> multipath won't keep switching pathgroups back and forth. The nodes that
> can see the higher priority pathgroup won't automatically switch back to
> it, since they weren't the ones that switched away from it. So the
> setting is more for a specific use case, and not a specific array type.
> 
> On the other hand, it is what the vendor tested, and with a single
> machine accessing the multipath device, you usually only switch away
> from the highest priority pathgroup because you lost access to all the
> paths in it. So it usually won't get stuck on a lower priority pathgroup
> while a higher priority one is usable, although that could happen.
> 
> Thoughts?

Yes, it is a weird value for pgfailback. But it's in two docs from
different vendors:
https://dl.acronis.com/u/software-defined/html/AcronisCyberInfrastructure_3_5_users_guide_en-US/accessing-iscsi/accessing-iscsi-targets-from-linux.html
and https://docs.virtuozzo.com/pdf/virtuozzo_hybrid_infrastructure_6_2_users_guide.pdf

I don't even know who the real manufacturer is.

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure to hwtable
  2025-09-11 17:56   ` Benjamin Marzinski
  2025-09-18 11:08     ` Xose Vazquez Perez
@ 2025-09-22 18:38     ` Martin Wilck
  2025-09-23  6:22       ` Martin Wilck
  1 sibling, 1 reply; 11+ messages in thread
From: Martin Wilck @ 2025-09-22 18:38 UTC (permalink / raw)
  To: Benjamin Marzinski, Xose Vazquez Perez; +Cc: Christophe Varoqui, DM_DEVEL-ML

On Thu, 2025-09-11 at 13:56 -0400, Benjamin Marzinski wrote:
> On Wed, Sep 10, 2025 at 09:41:57PM +0200, Xose Vazquez Perez wrote:
> > Source:
> > https://dl.acronis.com/u/software-defined/html/AcronisCyberInfrastructure_3_5_users_guide_en-US/accessing-iscsi/accessing-iscsi-targets-from-linux.html
> > 
> > Cc: Martin Wilck <mwilck@suse.com>
> > Cc: Benjamin Marzinski <bmarzins@redhat.com>
> > Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
> > Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
> > Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
> > ---
> >  libmultipath/hwtable.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
> > index 1a78c36d..12e10577 100644
> > --- a/libmultipath/hwtable.c
> > +++ b/libmultipath/hwtable.c
> > @@ -1371,6 +1371,21 @@ static struct hwentry default_hw[] = {
> >  		.pgpolicy      = GROUP_BY_SERIAL,
> >  		.no_path_retry = 30,
> >  	},
> > +	/*
> > +	 * Acronis
> > +	 */
> > +	{
> > +		// Cyber Infrastructure
> > +		.vendor        = "VSTORAGE",
> > +		.product       = "VSTOR-DISK",
> > +		.prio_name     = PRIO_ALUA,
> > +		.pgpolicy      = GROUP_BY_NODE_NAME,
> > +		.detect_prio   = DETECT_PRIO_OFF,
> > +		.features      = "2 pg_init_retries 50",
> > +		.pgfailback    = -FAILBACK_FOLLOWOVER,
> 
> I'm not sure about the pgfailback setting. the FAILBACK_FOLLOWOVER
> mode
> is not something that is really needed for a specific array type. It
> works like FAILOVER_IMMEDIATE, but it's designed to work so that if
> multiple nodes are using the same multipath device, and one of them
> loses access to the highest priority pathgroup but the others don't,
> multipath won't keep switching pathgroups back and forth. The nodes
> that
> can see the higher priority pathgroup won't automatically switch back
> to
> it, since they weren't the ones that switched away from it. So the
> setting is more for a specific use case, and not a specific array
> type.
> 
> On the other hand, it is what the vendor tested, and with a single
> machine accessing the multipath device, you usually only switch away
> from the highest priority pathgroup because you lost access to all
> the
> paths in it.

Not necessarily. path_group_prio_update() calculates the average of the
path priorities in the group. With ALUA and groups of 6+ paths, an
optimized group with one healthy path will have a lower prio (8) than a
non-optimized group with all healthy paths (10). In such a case it
could happen that multipathd switches to the non-optimized group and
never switches back.

I would suggest setting FAILBACK_IMMEDIATE instead. It's well
documented that FOLLOWOVER is only for cluster environments.

Regards
Martin

>  So it usually won't get stuck on a lower priority pathgroup
> while a higher priority one is usable, although that could happen. 




> 
> Thoughts?
> 
> -Ben
> 
> > +		.flush_on_last_del = FLUSH_ALWAYS,
> > +		.no_path_retry = NO_PATH_RETRY_QUEUE,
> > +	},
> >  	/*
> >  	 * EOL
> >  	 */
> > -- 
> > 2.51.0

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure to hwtable
  2025-09-22 18:38     ` Martin Wilck
@ 2025-09-23  6:22       ` Martin Wilck
  2025-10-05 18:21         ` Xose Vazquez Perez
  0 siblings, 1 reply; 11+ messages in thread
From: Martin Wilck @ 2025-09-23  6:22 UTC (permalink / raw)
  To: Benjamin Marzinski, Xose Vazquez Perez; +Cc: Christophe Varoqui, DM_DEVEL-ML

On Mon, 2025-09-22 at 20:38 +0200, Martin Wilck wrote:
> On Thu, 2025-09-11 at 13:56 -0400, Benjamin Marzinski wrote:
> > On Wed, Sep 10, 2025 at 09:41:57PM +0200, Xose Vazquez Perez wrote:
> > > Source:
> > > https://dl.acronis.com/u/software-defined/html/AcronisCyberInfrastructure_3_5_users_guide_en-US/accessing-iscsi/accessing-iscsi-targets-from-linux.html
> > > 
> > > Cc: Martin Wilck <mwilck@suse.com>
> > > Cc: Benjamin Marzinski <bmarzins@redhat.com>
> > > Cc: Christophe Varoqui <christophe.varoqui@opensvc.com>
> > > Cc: DM_DEVEL-ML <dm-devel@lists.linux.dev>
> > > Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
> > > ---
> > >  libmultipath/hwtable.c | 15 +++++++++++++++
> > >  1 file changed, 15 insertions(+)
> > > 
> > > diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
> > > index 1a78c36d..12e10577 100644
> > > --- a/libmultipath/hwtable.c
> > > +++ b/libmultipath/hwtable.c
> > > @@ -1371,6 +1371,21 @@ static struct hwentry default_hw[] = {
> > >  		.pgpolicy      = GROUP_BY_SERIAL,
> > >  		.no_path_retry = 30,
> > >  	},
> > > +	/*
> > > +	 * Acronis
> > > +	 */
> > > +	{
> > > +		// Cyber Infrastructure
> > > +		.vendor        = "VSTORAGE",
> > > +		.product       = "VSTOR-DISK",
> > > +		.prio_name     = PRIO_ALUA,
> > > +		.pgpolicy      = GROUP_BY_NODE_NAME,
> > > +		.detect_prio   = DETECT_PRIO_OFF,
> > > +		.features      = "2 pg_init_retries 50",
> > > +		.pgfailback    = -FAILBACK_FOLLOWOVER,
> > 
> > I'm not sure about the pgfailback setting. the FAILBACK_FOLLOWOVER
> > mode
> > is not something that is really needed for a specific array type.
> > It
> > works like FAILOVER_IMMEDIATE, but it's designed to work so that if
> > multiple nodes are using the same multipath device, and one of them
> > loses access to the highest priority pathgroup but the others
> > don't,
> > multipath won't keep switching pathgroups back and forth. The nodes
> > that
> > can see the higher priority pathgroup won't automatically switch
> > back
> > to
> > it, since they weren't the ones that switched away from it. So the
> > setting is more for a specific use case, and not a specific array
> > type.
> > 
> > On the other hand, it is what the vendor tested, and with a single
> > machine accessing the multipath device, you usually only switch
> > away
> > from the highest priority pathgroup because you lost access to all
> > the
> > paths in it.
> 
> Not necessarily. path_group_prio_update() calculates the average of
> the
> path priorities in the group. With ALUA and groups of 6+ paths, an
> optimized group with one healthy path will have a lower prio (8) than
> a
> non-optimized group with all healthy paths (10). In such a case it
> could happen that multipathd switches to the non-optimized group and
> never switches back.

Sorry, this example was incorrect. Only paths in UP or GHOST states are
counted in for the PG prio. In this example the optimized group would
still have p = 50, and what I described would not occur.

The example would be correct if the 5 non-"healthy" paths in the first
PG were in standby aka GHOST state (resulting in p = 55 / 6 = 9). But
that's a very different scenario, and highly theoretical.

> I would suggest setting FAILBACK_IMMEDIATE instead. It's well
> documented that FOLLOWOVER is only for cluster environments.

Despite the wrong example, I still think FAILBACK_IMMEDIATE makes
more sense as a general default. We can add a comment about the vendor
recommendations.

Martin

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure to hwtable
  2025-09-23  6:22       ` Martin Wilck
@ 2025-10-05 18:21         ` Xose Vazquez Perez
  0 siblings, 0 replies; 11+ messages in thread
From: Xose Vazquez Perez @ 2025-10-05 18:21 UTC (permalink / raw)
  To: Martin Wilck, Benjamin Marzinski; +Cc: Christophe Varoqui, DM_DEVEL-ML

On 9/23/25 8:22 AM, Martin Wilck wrote:

> On Mon, 2025-09-22 at 20:38 +0200, Martin Wilck wrote:

>> Not necessarily. path_group_prio_update() calculates the average of
>> the
>> path priorities in the group. With ALUA and groups of 6+ paths, an
>> optimized group with one healthy path will have a lower prio (8) than
>> a
>> non-optimized group with all healthy paths (10). In such a case it
>> could happen that multipathd switches to the non-optimized group and
>> never switches back.
> 
> Sorry, this example was incorrect. Only paths in UP or GHOST states are
> counted in for the PG prio. In this example the optimized group would
> still have p = 50, and what I described would not occur.
> 
> The example would be correct if the 5 non-"healthy" paths in the first
> PG were in standby aka GHOST state (resulting in p = 55 / 6 = 9). But
> that's a very different scenario, and highly theoretical.
> 
>> I would suggest setting FAILBACK_IMMEDIATE instead. It's well
>> documented that FOLLOWOVER is only for cluster environments.
> 
> Despite the wrong example, I still think FAILBACK_IMMEDIATE makes
> more sense as a general default. We can add a comment about the vendor
> recommendations.

I sent a new patch with that fixed.

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2025-10-05 18:21 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-10 19:41 [PATCH 0/3] multipath-tools: add new devices to hwtable Xose Vazquez Perez
2025-09-10 19:41 ` [PATCH 1/3] multipath-tools: add Acronis Cyber Infrastructure " Xose Vazquez Perez
2025-09-11 17:56   ` Benjamin Marzinski
2025-09-18 11:08     ` Xose Vazquez Perez
2025-09-22 18:38     ` Martin Wilck
2025-09-23  6:22       ` Martin Wilck
2025-10-05 18:21         ` Xose Vazquez Perez
2025-09-10 19:41 ` [PATCH 2/3] multipath-tools: add EqualLogic PS " Xose Vazquez Perez
2025-09-11 17:57   ` Benjamin Marzinski
2025-09-10 19:41 ` [PATCH 3/3] multipath-tools: add QSAN " Xose Vazquez Perez
2025-09-11 17:57   ` Benjamin Marzinski

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.