Archivo de la etiqueta: ORA-15274

Redundancia de los votingdisk en ASM

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Hoy vamos a ver un a entrada sencilla sobre la redundancia en los voting disk.
Supongamos tenemos un RAC con un votedisk en un grupo de ASM externo.

[grid@rac1 ~]$ crsctl query css votedisk
##  STATE    File Universal Id                File Name Disk group
--  -----    -----------------                --------- ---------
 1. ONLINE   9711d76755664f81bfeac1daf04aefcf (/dev/oracleasm/disks/OCRVOTING) [OCRVOTING]
Located 1 voting disk(s).

[grid@rac1 ~]$ ocrcheck
Status of Oracle Cluster Registry is as follows :
	 Version                  :          3
	 Total space (kbytes)     :     262120
	 Used space (kbytes)      :       2692
	 Available space (kbytes) :     259428
	 ID                       :  241611837
	 Device/File Name         : +OCRVOTING
                                    Device/File integrity check succeeded
                                    Device/File not configured
                                    Device/File not configured
                                    Device/File not configured
                                    Device/File not configured
	 Cluster registry integrity check succeeded
         Logical corruption check bypassed due to non-privileged user

Nosotros tenemos un DISKGROUP de ASM con redundancia HIGH , y queremos llevar nuestro votingdisk a este disco .

column name format a20;
column state format a20;
column type format a20;
select NAME,STATE,TYPE from v$asm_diskgroup;

NAME		     STATE		  TYPE
-------------------- -------------------- --------------------
OCRVOTING	     MOUNTED		  EXTERN
REDO		     DISMOUNTED
DATA		     MOUNTED		  HIGH
ACFS		     DISMOUNTED
OCRASM		     MOUNTED		  EXTERN

Ejecutamos el comando crsctl replace votedisk +DATA y recibiremos el siguiente error:

[grid@rac1 ~]$ crsctl replace votedisk +DATA
Failed to create voting files on disk group DATA.
Change to configuration failed, but was successfully rolled back.
CRS-4000: Command Replace failed, or completed with errors.

¿Como podemos saber mas de este error?

Vamos a mirar el alert.log del asm 

tail -900 /u01/app/oracle/diag/asm/+asm/+ASM1/trace/alert_+ASM1.log
TE: [crsctl.bin@rac1.pamplona.name (TNS V1-V3) 20094] opening OCR file
Wed Aug 19 11:39:20 2015
NOTE: updated gpnp profile ASM diskstring: /dev/oracleasm/disks/*
Wed Aug 19 11:39:20 2015
NOTE: Creating voting files in diskgroup DATA
Wed Aug 19 11:39:20 2015
NOTE: Voting File refresh pending for group 3/0xe73953ba (DATA)
NOTE: Attempting voting file creation in diskgroup DATA
NOTE: voting file allocation on grp 3 disk DATA_0000
NOTE: voting file allocation on grp 3 disk DATA_0001
NOTE: voting file allocation on grp 3 disk DATA_0002
ERROR: Voting file allocation failed for group DATA
Errors in file /u01/app/oracle/diag/asm/+asm/+ASM1/trace/+ASM1_ora_20102.trc:

Y que error tenemos en este fichero de traza?

cat /u01/app/oracle/diag/asm/+asm/+ASM1/trace/+ASM1_ora_20102.trc
..
.

*** 2015-08-19 11:39:24.754
Updating headers of disk /dev/oracleasm/disks/ASM03 with 96 128
PST-new:0x7f6053f8fe60:0x9f1d9478:45:
  /dev/oracleasm/disks/ASM03:67f2cd24882e4f46bfe07f85554e0d33:
ORA-15274: Not enough failgroups (5) to create voting files

Como podemos ver, el GRID ha visto que nuestro grupo de ASM no cuenta con 5 failgroups ( solamente cuenta con 3 discos), con lo que ha echado atrás la operación.

Que pasaría si quisiesemos llevarlo a otro external?

Si queremos llevarlo a otro external veremos que funciona correctamente.

[grid@rac1 ~]$ crsctl replace votedisk  +OCRASM
Successful addition of voting disk 5f3f3404c2cd4f24bfa6ca5de9494bba.
Successful deletion of voting disk 9711d76755664f81bfeac1daf04aefcf.
Successfully replaced voting disk group with +OCRASM.
CRS-4266: Voting file(s) successfully replaced

Y si quisiéramos añadir otra ASM con redundancia external?

[grid@rac1 ~]$ crsctl add css votedisk +OCRVOTING
CRS-4671: This command is not supported for ASM diskgroups.
CRS-4000: Command Add failed, or completed with errors.

Vemos como tampoco nos permite el poner el voting disk en 2 ASM DISKGROUPS

Conclusiones

Podemos beneficiarnos (y es aconsejable) de la redundancia del ASM para el voting disk, pero, hay que tener en cuenta que :

  • No podemos mezclar voting disk en asm y no asm
  • Voting disk necesita unos determinados failugre groups en ASM
    • External: No ha dependencia ya que se gestiona externamente
    • Normal: Deberemos de tener un mínimo de 3 failgroups
    • External: deberemos de terner un mínimo de 5 failgroups
  • Si usamos ASM para los voting disk la redundancia la marca el ASM