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2 replies Latest Post - ‏2013-02-21T01:56:26Z by amanabe
59 Posts

Pinned topic Disk TieBreaker multipath support

‏2013-02-19T11:32:44Z |
I found an old Technote(copied below) that that describes Disk TieBreaker support single path connection only.
Does someone knows the latest information or has experience using Disk TieBreaker in multipath environment(ex.RDAC driver)?

From TSAMP V3.2.1.3 TieBeaker type SCSIPR supported include Linux on system z environment.
I would like to know if this Technote's restriction also applies to Linux on System z multipath environment(with multipath-tools).

Best Regards
Atsushi Manabe(

TSAMP support for DS4300 Fibre Channel Switch
DocNumber: 1224349 DocType: Technotes (FAQs)
Product: Tivoli System Automation for Multiplatforms ProductAlias:
Component: -- DispOriginator: Gareth Holl
DocExpire: 09/22/2011 PublishDate: 11/5/09
Publishto: Public/Basic (Internet) Status: Archived
Attr1: All Platforms Attr2: 2.1
Date: 11/30/05 7:04:40 PM

Abstract: Does IBM Tivoli System Automation for Multiplatforms (TSAMP) work with a two Fiber Channel DS4300 Switch ?

AdditionalKeywords: DS4300 Fibre Channel Switch SCSI tiebreaker SAN disk support

Content: Generally speaking, the hardware used for SAN/Disk storage would be transparent
to TSAMP. However there's an issue if the you want to use the SCSI TieBreaker
connected over a Multipath connection. This is not supported. In this
situation, you could use the network tiebreaker as an alternative.

Disk TieBreaker would provide better reliability, but it would only be possible
if the disk was connected to the nodes with a single path connection.
Updated on 2013-02-21T01:56:26Z at 2013-02-21T01:56:26Z by amanabe
  • Enrico_Joedecke
    109 Posts

    Re: Disk TieBreaker multipath support

    ‏2013-02-19T12:12:57Z  in response to amanabe
    Konnichiha Manabe-san,

    the restriction mentioned within the old Technote only applies to the 'SCSI' - TieBreaker, because this only uses SCSI-2 reservation, that does not support multipath environments.
    The new 'SCSIPR' TieBreaker uses SCSI-3 persistent reserve, and this is supporting multipath. In fact this new SCSIPR TieBreaker has been introduced to provide support for multipath environments.

    Thank you,
    Enrico Joedecke
    • amanabe
      59 Posts

      Re: Disk TieBreaker multipath support

      ‏2013-02-21T01:56:26Z  in response to Enrico_Joedecke
      konnichiwa Enrico-san
      Thanks for your prompt answer.

      Because something not working as expected in our colleague's zLinux environment, we will consider to open PMR.

      Atsushi Manabe(