Latency Numbers Every Programmer Should Know

Интересная ссылка про относительное время доступа к данным :

http://www.eecs.berkeley.edu/~rcs/research/interactive_latency.html

У меня в IE не открылась, пробуйте что-то другое.

256g RAM per DB node with no price changes

CRS-2674: Start of 'ora.net1.network' on 'ed02dbadm02' failed

Accidentally Exadata was installed with wrong netmask 255.255.255.0 instead of 255.255.254.0.

How to correct this mistake easily ?

Solution:

Correct manually client net /etc/sysconfig/network-scripts/ifcfg-bondeth0
and set right    NETMASK=255.255.254.0

And same for mgmt net: ifcfg-eth0

then    ... service network restart ...

As a result we obtained errors in clusterware components:

[root@ed02dbadm01 ~]# crsctl start resource ora.LISTENER.lsnr
CRS-2672: Attempting to start 'ora.net1.network' on 'ed02dbadm01'
CRS-2672: Attempting to start 'ora.net1.network' on 'ed02dbadm02'
CRS-2674: Start of 'ora.net1.network' on 'ed02dbadm01' failed
CRS-2674: Start of 'ora.net1.network' on 'ed02dbadm02' failed
CRS-4000: Command Start failed, or completed with errors.
[root@ed02dbadm01 ~]#
[root@ed02dbadm01 ~]# crsctl start resource ora.net1.network
CRS-2672: Attempting to start 'ora.net1.network' on 'ed02dbadm01'
CRS-2672: Attempting to start 'ora.net1.network' on 'ed02dbadm02'
CRS-2674: Start of 'ora.net1.network' on 'ed02dbadm01' failed
CRS-2674: Start of 'ora.net1.network' on 'ed02dbadm02' failed
CRS-4000: Command Start failed, or completed with errors.

The root cause is the 'ora.net1.network' component.
Look at it carefully:
[root@ed02dbadm01 ~]# crsctl stat res ora.net1.network -p
...
USR_ORA_IF=bondeth0
USR_ORA_NETMASK=255.255.255.0
USR_ORA_SUBNET=172.31.4.0
...

And correct the USR_ORA_NETMASK=255.255.255.0:

# crsctl modify resource ora.net1.network -attr "USR_ORA_NETMASK=255.255.254.0"


And now the problem is solved :

ora.LISTENER.lsnr
               ONLINE  ONLINE       ed02dbadm01
               ONLINE  ONLINE       ed02dbadm02

ora.net1.network
               ONLINE  ONLINE       ed02dbadm01
               ONLINE  ONLINE       ed02dbadm02
ora.LISTENER_SCAN1.lsnr
      1        ONLINE  ONLINE       ed02dbadm02
ora.LISTENER_SCAN2.lsnr
      1        ONLINE  ONLINE       ed02dbadm01
ora.LISTENER_SCAN3.lsnr
      1        ONLINE  ONLINE       ed02dbadm01
ora.ed02dbadm01.vip
      1        ONLINE  ONLINE       ed02dbadm01
ora.ed02dbadm02.vip
      1        ONLINE  INTERMEDIATE ed02dbadm01              FAILED OVER
ora.scan1.vip
      1        ONLINE  ONLINE       ed02dbadm02
ora.scan2.vip
      1        ONLINE  ONLINE       ed02dbadm01
ora.scan3.vip
      1        ONLINE  ONLINE       ed02dbadm01


Don't forget change netmask in the ILOM.