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Showing posts from November, 2007

NFS - could not chdir home directory

After political and time pressure not to pursue any commercial products to integrate Linux user authentication into MS AD, I'm falling back to my original plan to set-up NIS(+) for now and deal with AD later...
I followed instructions at Linux Home Networking and got the NFS server running but would get an error when logging in as a user: "unable to chdir to home directory". Fortunately, it seems a common error when using NIS and NFS (and Kerberos). It turns out my NFS client wasn't correctly configured. The automount file /etc/auto.home for /home listed my subnetwork (10.X.0.0/16). That's what I had the NFS server configured for. The automount file should just list '*' there... Next is NIS...

1,500 companies adopt Oracle Unbreakable Linux

Oracle Wednesday said that 1,500 companies have signed up for its Unbreakable Linux discount support program since it was announced one year ago.
The number of customers is impressively greater than the number Oracle announced six months ago -- 26. And that was with "virtually no selling at all" of Unbreakable Linux, bragged CEO Larry Ellison during his keynote speech at OpenWorld on Wednesday.
Source: LinuxWorld

Linux-AD Integration

While setting up a schema to handle Linux user authentication and authorization using our big corporate Windows Active Directory (AD) server, I ran across a TechEd session that mentioned Scott Lowe's blog.
On his very nice looking tech blog, I found a great article describing clearly how to integrate Linux into an AD running on Windows Server 2003 R2. Mind you, Server 2008 - the next release - will be somewhat different and older version of Windows Server as well. It mainly has to do with the RFC2307 or the Server for Unix (SfU) from Microsoft.

FAQ: Oracle VM

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There is a quick FAQ on Oracle VM, explaining the basics about Oracle new virtualization technology. For instance, basic OracleVM is free as anyone can download the binaries. Support is available on a per-socket basis, not per-core. There are also ready-made templates with Oracle Linux (OEL) 4 update 5 for both 32 bit and 64 bit VMs. You will manage VMs with Oracle VM Manager.

Oracle supports their own database 10g and 11g inside OracleVM, as well as OEM, Siebel, Peoplesoft and E-business Suite. Support for Oracle RAC clusters will be available somewhere in 2008. Testing is in progress, but timing issues in RAC are very strict, so it must be thoroughly tested.

The requirements for OracleVM as similar to Xen's requirements: a new/recent CPU with VTX virtualization extensions is required for running VMs with Windows. If you only run Linux, you can use older hardware as well (and a kernel supporting paravirtualization).

Disk performance issues with Oracle Linux?

While we ourselves did not have any performance issues of our Dell Poweredge 2950 using 2 Qlogic qle2460 HBAs to connect to an EMC DMX-3 SAN over Cisco FC switches, some of our colleagues at another subsidiary did have problems: only 50MB/s using the bonnie disk benchmark where we got 240MB/s... Clearly something was different.
Investigations showed they were using LVM on the LUNs and created partitions within LVM. We did not use LVM but gave bare LUNs to OracleASM to manage and control.

This led to believe that misalignment of the partition to physical disk cylinder may have caused additional overhead. Because LVM created an MBR on the disk's first set of cylinders, the first partition was created starting at cylinder 63. As this is not a power of 2, the disk subsystem experiences overhead as it translates the numbers back and forth. Research showed that both Oracle and EMC's best-practices both recommend to align your partitions on power of two cylinders! There is a best-pract…

Podcast: What is OracleVM?

Here is a podcast (mp3) with an Oracle architect on Oracle's lastest entry in the virtualization market: OracleVM.

Oracle Linux Engineering team member Kurt Hackel explains the origins of and motivations behind the release of the Xen-based Oracle VM and tells customers what they need to know about deployment and performance.

Source: Oracle Technology Network TechCasts