Topic
  • 4 replies
  • Latest Post - ‏2013-07-12T16:13:31Z by dlmcnabb
yard
yard
10 Posts

Pinned topic NSD on file ?

‏2013-07-11T15:23:27Z |

Hi All

I have question regard NSD creation.
We have GPFS replication (Sync) and also Tie-Breaker node.I want to know if i can define NSD local on the Tie-Breaker node on a file and not on partition ?

Here is my setup :

[root@comp01-ib0 gpfs]# cat d
 /quorum/tbdisk:::descOnly:1:tbdisk:

[root@comp01-ib0 gpfs]# mmcrnsd -F d
mmcrnsd: Processing disk /quorum/tbdisk
mmcrnsd: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.
[root@comp01-ib0 gpfs]# mmlsnsd

 File system   Disk name    NSD servers                                    
---------------------------------------------------------------------------
 gpfs          nsd1_1       comp01.gts.lab,comp02.gts.lab
 gpfs          nsd1_2       comp01.gts.lab,comp02.gts.lab
 gpfs          nsd_pool1    (directly attached)      
 (free disk)   tbdisk       (directly attached)      

[root@comp01-ib0 gpfs]# cat d
# /quorum/tbdisk:::descOnly:1:tbdisk:
tbdisk:::descOnly:1::system


[root@comp01-ib0 gpfs]# mmadddisk gpfs -F d
Failed to read a file system descriptor.
Input/output error
mmadddisk: Unexpected error from mmcommon onactive tslsfs -B.  Return code: 5
mmadddisk: Command failed.  Examine previous error messages to determine cause.

Please advise

Updated on 2013-07-11T15:23:54Z at 2013-07-11T15:23:54Z by yard
  • dlmcnabb
    dlmcnabb
    1012 Posts

    Re: NSD on file ?

    ‏2013-07-11T22:44:23Z  

    You need to define an NSD server for that "disk". Only one node can see it.

  • yard
    yard
    10 Posts

    Re: NSD on file ?

    ‏2013-07-12T08:17:13Z  
    • dlmcnabb
    • ‏2013-07-11T22:44:23Z

    You need to define an NSD server for that "disk". Only one node can see it.

    Hi

    The problem was solve - i had to define large file than what i have which was 4k.

    I define new file with 1G size - problem solved.

    Thanks

  • gcorneau
    gcorneau
    149 Posts

    Re: NSD on file ?

    ‏2013-07-12T13:46:23Z  
    • yard
    • ‏2013-07-12T08:17:13Z

    Hi

    The problem was solve - i had to define large file than what i have which was 4k.

    I define new file with 1G size - problem solved.

    Thanks

    A minor, non-technical comment:  I know our documentation calls this node a tiebreaker node, but wanted to point out that this is not the same things as the quorum-based TieBreaker disk set via the mmchconfig.  That term refers to a disk shared between quorum nodes.  This descriptor only disk is attached only to one node.

    Naming it thusly won't cause any problems with the GPFS code, but may confuse someone (other than yourself) who's looking at things later.

    One other thing: since it looks like you're doing a 3 site disaster recovery configuration with GPFS replication, you'll want to make sure the failure group for the descriptor only disk is set to a different value from the siteA and siteB disks.   This is mentioned in the Advanced Administration Guide here:

    http://publib.boulder.ibm.com/infocenter/clresctr/vxrx/topic/com.ibm.cluster.gpfs.v3r5.gpfs200.doc/bl1adv_actactset.htm

  • dlmcnabb
    dlmcnabb
    1012 Posts

    Re: NSD on file ?

    ‏2013-07-12T16:13:31Z  
    • yard
    • ‏2013-07-12T08:17:13Z

    Hi

    The problem was solve - i had to define large file than what i have which was 4k.

    I define new file with 1G size - problem solved.

    Thanks

    The file only needs to be 2M+8. So you can create a descOnly "disk" in a file with

    dd if=/dev/zero of=$filename count=1 seek=3m

    If the underlying filesystem can handle sparse files, then hardly any space used.