Server error: ‘The backing device /dev/mapper/xyz is not allowed to contain partitions’ on OracleVM

Ok, I added a new disk (well old actually, but new for the machine) to my Oracle VM server. It discovered it (or do it manually) and I wanted to create a new repository on it. Unfortunately it came with the following error:

Server error: 'The backing device /dev/mapper/3500a075109146bee is not allowed to contain partitions'

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Oracle Grid 12c and Linux 7: PRVE-0421 : No entry exists in /etc/fstab for mounting /dev/shm

When you run Oracle Grid 12c ‘cluvfy stage -pre crsinst’ on Linux 7 (Oracle Enterprise Linux 7.2 in my case) you will get the following error:

Starting check for /dev/shm mounted as temporary file system ...


PRVE-0421 : No entry exists in /etc/fstab for mounting /dev/shm
PRVE-0421 : No entry exists in /etc/fstab for mounting /dev/shm
PRVE-0421 : No entry exists in /etc/fstab for mounting /dev/shm
PRVE-0421 : No entry exists in /etc/fstab for mounting /dev/shm

Check for /dev/shm mounted as temporary file system failed

When you do a ‘df -h’ you will see that ‘/dev/shm’ actually is mounted:

Filesystem Size Used Avail Use% Mounted on
devtmpfs 24G 0 24G 0% /dev
tmpfs    24G 0 24G 0% /dev/shm

This is due to a bug (Doc ID 2065603.1) which comes from the case that the cluvfy check does not check the actual mount of the file system, but looks for the persistence line of this mount in ‘/etc/fstab’ like it did in Linux 6. In Linux 7 you get this tmpfs mount by default.

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Add a larger disk and remove smaller disk from LVM, online!

Goal: To add new larger disk to LVM, move data and remove old smaller one

When using Oracle VM in my work, a disk can be enlarged in Oracle VM manager for a virtual machine. But because of an internal loop-mount on the XEN hypervisor level, the disk-file which is presented to the virtual machine as a disk, is not able to ‘pass on’ it’s resize information to the OS. This requires an unmount and mount of the disk-file on hypervisor level, or in simple words: a reboot of the virtual machine… yikes! Continue reading

*ALL* Oracle database patches… Linux and Windows… (on Metalink)

Linux and Windows…

Quick Reference To Patch Numbers For Database PSU, SPU(CPU) And Bundle Patches [ID 1454618.1]

…more Windows

Oracle Database, Networking and Grid Agent Patches for Microsoft Platforms [ID 161549.1]


Happy patching!

Booting Oracle VM / Linux (ISOs) with UEFI ‘bios’ does not work

It seems Oracle VM (<=3.3.1 *) and Oracle Linux (<= 5.10/6.6 *) both install ISOs and installed OS’s are not capable of booting when UEFI on the bare-metal hardware is used. I have seen two configurations now where this happened, one using a USB HDD drive capable providing a ISO to boot from as CD/DVD (Zalman ZM-VE300)  and one HP iLO4 (http and local ISO) ‘remote’ booting. Continue reading

OpenSSL Heartbleed Oracle fixed version is 1.0.1e-16.el6_5.7

When one is looking for the OpenSSL fix 1.0.1g for Oracle (Red Hat) Linux 6, the fixed package version is ‘1.0.1e-16.el6_5.7’. I think this a bit misleading, because OpenSSL 1.0.1e is subject to the bug (CVE-2014-0160). But from the Red Hat site: and Orcale MetaLink (MOS Note 1663998.1): “Version openssl-1.0.1e-16.el6_5.7 included a fix backported from openssl-1.0.1g.

Some simple OS tests can produce a false-positive to heartbleed tests, becasue it could look only for text other than 1.0.1g.


To update to the ‘latest’ OpenSSL version, enable the [OL6_latest] repository en ‘yum update openssl’:

Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package openssl.x86_64 0:1.0.1e-15.el6 will be updated
---> Package openssl.x86_64 0:1.0.1e-16.el6_5.7 will be an update
--> Finished Dependency Resolution

Testing for processes using OpenSSL

One can test if processes are using OpenSSL (not a heartbleed vulnerability test), by issuing one of these two following commands:

$ lsof | awk 'NR==1 || $0~/'
$ grep /proc/*/maps |cut -d/ -f3 |sort -u |xargs -r -- ps uf

More info

OpenSSL Security Bug – Heartbleed / CVE-2014-0160

Document written at April the 18th, 2014…

Happy blee, uh, testing and patching!

Direct NFS, configuring and network considerations in practise

Oracle Direct NFS (dNFS for short) is an NFS Client functionality integrated directly in the Oracle database software, optimizing the I/O (multi)path to your NFS storage without the overhead of the OS client/kernel software.

In this blog post I’ll describe network considerations, configurations and problems I have encountered during set-ups I have done.

dNFS uses two kinds of NFS mounts, the OS mount of NFS (also referred to as kernel NFS of kNFS) and, of course, Oracle’s database NFS mount, Direct NFS or dNFS.

According to [Direct NFS: FAQ (Doc ID 954425.1)] and [How to configure DNFS to use multiple IPs (Doc ID 1552831.1)], an kNFS mount is needed, although Oracle also claims it will also work on platforms that don’t natively support NFS, e.g. Windows… [Oracle Database 11g Direct NFS Client White Paper] (I don’t know how yet…).

Because dNFS implements multipath I/O internally, these is no need for bonding the interfaces to storage via active-backup or Link Aggregation. However, it’s good practice to bond the OS kNFS connection:

1 - eth0 -\
           - bond0 - OS / kNFS
2 - eth1 -/
3 - eth2 --------- - dNFS path 1
4 - eth3 --------- - dNFS path 2

Above schematic shows [How to configure DNFS to use multiple IPs (Doc ID 1552831.1)]:
“A good solution could be to use bonded NICs (…) to perform the mount and then use unbonded NICs via dNFS for the performance critical path.” Continue reading

The oratab usage comment is not correct… or it’s a bug in dbstart/dbshut (sort of)…

I’m talking about the ‘third’ field in the database entries. Field number three. Which indicates there could be a fourth, fifth etc… right?

A customer where I came (who went from AIX to Linux), who had interpreted this comment and therefore expanded the oratab with an extra column, to datapump the database (y/n).

When I shut down the databases, there was some unexpected behaviour when I invoked dbshut… Strange, but the extra (last) field ‘for datapump’ was read, not the third!

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Bug: /def/shm does not use /etc/fstab attributes after reboot

There is a bug in Red Hat Linux 6 and Oracle Enterprise Linux 6 (UEK and RHEL-kernel) and probably all other Red Hat 6 related Linux Distro’s.

When you need more memory for SGA/PGA when using MEMORY_MAX_TARGET, you need to resize /dev/shm. By default this is 50% of total memory and Oracle tells you to add the following to /etc/fstab:

shmfs /dev/shm tmpfs size=3g 0 0

Which works… Continue reading

Oracle Linux 6, oracle-validated is missing? no renamed!

In Oracle Linux 6, it looks like the ‘oracle-validated’ package is missing, but Oracle actually renamed it to ‘oracle-rdbms-server-11gR2-preinstall.x86_64‘.

To quickly use the public yum repository of Oracle and install ‘oracle-rdbms-server-11gR2-preinstall.x86_64’:

cd /etc/yum.repos.d
#vi /etc/yum.repos.d/public-yum-ol6.repo
yum clean all
yum repolist
yum install oracle-rdbms-server-11gR2-preinstall.x86_64

You will get the ‘latest’ build enabled.
If you don’t want this, vi /etc/yum.repos.d/public-yum-ol6.repo .

Happy installing!