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Multipath with HP LeftHand on RHEL

December 10, 2012 by · Leave a Comment

HP has acquired LeftHand networks and re-branded the LeftHand storage product to the HP P4000 storage series. This is a iSCSI SAN product targeted at entry level businesses. We are using this product for various projects, where our Oracle RAC cluster is one of them. For this cluster where are setting up MPIO. Because we are using interface bonding at the moment the LUN’s are configured already and don’t have to be created.

Quick environment specs:

  • RedHat EL5.8
  • 2 NIC’s in the storage network (eth3 and eth4)

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Filed Under: Linux, Oracle · Tagged With: , , , , ,

Oracle 11g ASM disk discovery

January 20, 2012 by · 1 Comment

During the installation of Oracle 11gR2 on Red Hat Enterprise Linux 5 I stumbled upon a incorrect default setting for ASM disk discovery when using ASM lib. The discovery path is set to ‘/dev/raw/sd*’, which is incorrect because ASM lib creates the devices under ‘/dev/oracleasm/disks’.

Another thing to be aware of is the ownership of the disks. You need to run ‘/etc/init.d/oracleasm configure’ in order to configure the owner. If you just hit return the ownership of the disks is set to root. Because you will start the Oracle installation as user oracle the disks will not appear in the discovery step during the installation.

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Filed Under: Oracle · Tagged With: , , ,

SCOM 2007 and RHEL6

July 20, 2011 by · Leave a Comment

Cumulative Update 5 for System Center Operations Manager 2007 R2 brings support for Red Hat 6. This update is release on August 4, 2011. Red Hat Enterprise Linux 6 was release on November 10, 2010. So Microsoft managed to put out an update with support for RHEL6 9 months later. This new management pack is not included in the update, you have to download en and import it separately.

Filed Under: Linux · Tagged With: ,

Install SCOM agent on Red Hat Linux

March 3, 2010 by · 6 Comments

The steps below describe how to install the SCOM agent on Red Hat Linux 5 x64. We don’t like to enroll the agent by using the SCOM Discovery wizard, as you need to enter the super-user (root)credentials and we’re not sure where the application stores those credentials and it’s used for. So we’re still searching for the minimal permissions for the agent to be installed.

It is possile to install the agent, copy the unsigned client-side generated certificate to the SCOM server, sign the certificate on the SCOM server and copy the signed certificate back to the client. Once you have restarted the scx daemon you can use the discovery wizard on the SCOM server to add the server without using super-user credentials in SCOM.

Once you have installed the Cross Platform Cumulative Update 2 for System Center Operations Manager 2007 R2, a newer version of the agent becomes available on the SCOM server in Program Files\System Center Operations Manager 2007\AgentManagement\UnixAgents.


# rpm -ivh scx-1.0.4-258.rhel.5.x64.rpm
Preparing...                ########################################### [100%]
   1:scx                    ########################################### [100%]
Generating certificate with hostname="host001", domainname="example.local"

WARNING!
Could not read 256 bytes of random data from /dev/random. Will revert to less secure /dev/urandom.
See the security guide for how to regenerate certificates at a later time when more random data might be available.

/var/tmp/rpm-tmp.63356: line 163: /usr/lib/lsb/install_initd: No such file or directory
Starting Microsoft SCX CIM Server: [  OK  ]
#

To fix the above problem you can use the following work-around.

rm /dev/random
rm: remove character special file `/dev/random'? y
# mknod -m 644 /dev/random c 1 9
# chown root:root /dev/random
# cd
# rpm -ivh scx-1.0.4-258.rhel.5.x64.rpm
Preparing...                ########################################### [100%]
   1:scx                    ########################################### [100%]
Generating certificate with hostname="host001", domainname="example.local"
/var/tmp/rpm-tmp.10879: line 163: /usr/lib/lsb/install_initd: No such file or directory
Starting Microsoft SCX CIM Server: [  OK  ]
# rm /dev/random
# mknod -m 644 /dev/random c 1 8
# chown root:root /dev/random


Filed Under: Linux · Tagged With: , ,