Reloading multipathd?

Reloading multipathd?

[S. J. van Harmelen]

Hi...

I just added another LUN on our storage (MD3000). But now that I run
multipath -ll I don't see the new LUN.

Do I need to reload something (like /etc/init.d/multipath-tools reload
maybe)? And if so, can I do this without it interrupting the
connectivity of the other (production) LUN's?

Sander

RE: Reloading multipathd?

[Paul Cote]

Did you do a rescan so that the O/S "sees" the new LUN? If so; simply do
a multipath -v2 to build the new path list.

-----Original Message-----
From: dm-devel-bounces@redhat.com [mailto:dm-devel-bounces@redhat.com]
On Behalf Of S. J. van Harmelen
Sent: Wednesday, November 07, 2007 8:08 AM
To: device-mapper development
Subject: [dm-devel] Reloading multipathd?

Hi...

I just added another LUN on our storage (MD3000). But now that I run
multipath -ll I don't see the new LUN.

Do I need to reload something (like /etc/init.d/multipath-tools reload
maybe)? And if so, can I do this without it interrupting the
connectivity of the other (production) LUN's?

Sander

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RE: Reloading multipathd?

[S. J. van Harmelen]

On Wed, 2007-11-07 at 08:33 -0500, Paul Cote wrote:
> Did you do a rescan so that the O/S "sees" the new LUN? 

Nope... Could you tell me how to do that? And does a rescan have any
effect on already active LUN's?


> If so; simply do
> a multipath -v2 to build the new path list.
> 
> -----Original Message-----
> From: dm-devel-bounces@redhat.com [mailto:dm-devel-bounces@redhat.com]
> On Behalf Of S. J. van Harmelen
> Sent: Wednesday, November 07, 2007 8:08 AM
> To: device-mapper development
> Subject: [dm-devel] Reloading multipathd?
> 
> Hi...
> 
> I just added another LUN on our storage (MD3000). But now that I run
> multipath -ll I don't see the new LUN.
> 
> Do I need to reload something (like /etc/init.d/multipath-tools reload
> maybe)? And if so, can I do this without it interrupting the
> connectivity of the other (production) LUN's?
> 
> Sander
> 
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> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
> 
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RE: Reloading multipathd?

[Domenico Viggiani]

> -----Original Message-----
> From: dm-devel-bounces@redhat.com 
> [mailto:dm-devel-bounces@redhat.com] On Behalf Of S. J. van Harmelen
> Sent: Wednesday, November 07, 2007 4:19 PM
> 
> On Wed, 2007-11-07 at 08:33 -0500, Paul Cote wrote:
> > Did you do a rescan so that the O/S "sees" the new LUN? 
> 
> Nope... Could you tell me how to do that? And does a rescan 
> have any effect on already active LUN's?

# Send a LIP (loop initialization primitive) to the fabric 0
echo "1" > /sys/class/fc_host/host0/issue_lip 

# Scan SCSI bus 0:
echo "- - -" > /sys/class/scsi_host/host0/scan

# Send a LIP (loop initialization primitive) to the fabric 1
echo "1" > /sys/class/fc_host/host1/issue_lip 

# Scan SCSI bus 1:
echo "- - -" > /sys/class/scsi_host/host1/scan

# sometime is needed to repeat above steps two times?

# Check /var/log/messages and /proc/scsi/scsi

# Create multipath
multipath -v2
multipath -ll

RE: Reloading multipathd?

[S. J. van Harmelen]

On Wed, 2007-11-07 at 16:44 +0100, Domenico Viggiani wrote:
> > -----Original Message-----
> > From: dm-devel-bounces@redhat.com 
> > [mailto:dm-devel-bounces@redhat.com] On Behalf Of S. J. van Harmelen
> > Sent: Wednesday, November 07, 2007 4:19 PM
> > 
> > On Wed, 2007-11-07 at 08:33 -0500, Paul Cote wrote:
> > > Did you do a rescan so that the O/S "sees" the new LUN? 
> > 
> > Nope... Could you tell me how to do that? And does a rescan 
> > have any effect on already active LUN's?
> 
> # Send a LIP (loop initialization primitive) to the fabric 0
> echo "1" > /sys/class/fc_host/host0/issue_lip 

Thanks for you help. But the MD3000 has SAS HBA's, so I don't have the
issue_lip file on my system.

Any other way to get the same results for a SAS HBA?

And once again... Does this interrupt the LUN's that are already
attached and in use?

Thanks!!

> 
> # Scan SCSI bus 0:
> echo "- - -" > /sys/class/scsi_host/host0/scan
> 
> # Send a LIP (loop initialization primitive) to the fabric 1
> echo "1" > /sys/class/fc_host/host1/issue_lip 
> 
> # Scan SCSI bus 1:
> echo "- - -" > /sys/class/scsi_host/host1/scan
> 
> # sometime is needed to repeat above steps two times?
> 
> # Check /var/log/messages and /proc/scsi/scsi
> 
> # Create multipath
> multipath -v2
> multipath -ll
> 
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Re: Reloading multipathd?

[malahal]

S. J. van Harmelen [svh@dds.nl] wrote:
> 
> Thanks for you help. But the MD3000 has SAS HBA's, so I don't have the
> issue_lip file on my system.
> 
> Any other way to get the same results for a SAS HBA?
> 
> And once again... Does this interrupt the LUN's that are already
> attached and in use?

LIP does interrupt the communication for a while, but ideally everything
would be retried on block devices at least. I don't think you need to
generate LIP in some instances (depends on how you added your LUN, E.g.
if you added new FC disk to FC Fabric switch, the Fabic would generate
an event, RSCN, without interrupting anything).

I don't know SAS world equivalents...

RE: Reloading multipathd?

[Paul Cote]

>could you tell me how to do that? 

You can use the 'rescan SCSI Bus" script found at:
http://www.garloff.de/kurt/linux/

Optionally; if you have FC HBA's ... Emulex and Qlogic both have their
home grown rescan scripts as well.

>and does a rescan have any effect on already active LUN's?

No.

-----Original Message-----
From: dm-devel-bounces@redhat.com [mailto:dm-devel-bounces@redhat.com]
On Behalf Of S. J. van Harmelen
Sent: Wednesday, November 07, 2007 10:19 AM
To: device-mapper development
Subject: RE: [dm-devel] Reloading multipathd?


On Wed, 2007-11-07 at 08:33 -0500, Paul Cote wrote:
> Did you do a rescan so that the O/S "sees" the new LUN?

Nope... Could you tell me how to do that? And does a rescan have any
effect on already active LUN's?


> If so; simply do
> a multipath -v2 to build the new path list.
> 
> -----Original Message-----
> From: dm-devel-bounces@redhat.com [mailto:dm-devel-bounces@redhat.com]
> On Behalf Of S. J. van Harmelen
> Sent: Wednesday, November 07, 2007 8:08 AM
> To: device-mapper development
> Subject: [dm-devel] Reloading multipathd?
> 
> Hi...
> 
> I just added another LUN on our storage (MD3000). But now that I run 
> multipath -ll I don't see the new LUN.
> 
> Do I need to reload something (like /etc/init.d/multipath-tools reload

> maybe)? And if so, can I do this without it interrupting the 
> connectivity of the other (production) LUN's?
> 
> Sander
> 
> --
> dm-devel mailing list
> dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
> 
> --
> dm-devel mailing list
> dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel

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