SHIFT-WIKI - Sjoerd Hooft's InFormation Technology
This WIKI is my personal documentation blog. Please enjoy it and feel free to reach out through blue sky if you have a question, remark, improvement or observation. See below for the latest additions, or use the search or tags to browse for content.
Red Hat ACL or Extended Permissions
Summary: How to work with ACLs on Red Hat.
Date: Around 2014
Refactor: 29 March 2025: Checked links and formatting.
The filesystems ext2/3/4 also support more complex file permissions called ACLs. I will not cover that deeply, just enough to get you going.
Red Hat Enterprise Linux 6.5 Management Server
Summary: How to configure a Red Hat Management Server. This means a complete installation as well as setting up the kickstart installation server.
Date: Around 2014
Refactor: 29 March 2025: Checked links and formatting.
This article is the first, or actually the second in a series of installing Red Hat Enterprise Linux at a company. Right now I work in a Windows based environment, but unfortunately for my colleagues not every application runs on Windows. Especially the ones that are designed to do a lot of math based tasks, in this case risk calculations. In previous versions, these applications were installed on physical hardware with Solaris and a little bit of an ancient Red Hat edition. However, new releases, new chances and I had the chance to recreate everything from scratch, supported and well, on virtualized hardware. So I've already done my homework and got together a best practices for Red Hat on VMware, created a design which included a management server, a NFS server and all required application and database server. This article is about the management server. The idea is that this server will be the central point in the linux environment and will be used as an installation server, as well as the OS as software and patches, the Mercurial versioning master repository and a few more smaller functions. More then that, this is the first server, so it will be installed from scratch, and this is the report.
At the end you can read how to use this management server to install other servers, which is then followed by a Post Install follow-up.
Enjoy.
Update: I also came up with a requirement to mount Windows shares to some of my Linux boxes, I finally opted for Windows NFS and documented that here.
NetApp Reallocate
Summary: How to run reallocation on a NetApp Filer.
Date: Around 2014
Refactor: 29 March 2025: Checked links and formatting.
Storage vMotion with RDM Disks
Summary: How to do a storage vMotion with RDM disks on vSphere.
Date: Around 2014
Refactor: 29 March 2025: Checked links and formatting.
I had a use case where some VMs with Microsoft Clustering had to be moved to different datastores. That is, the normal VMDK OS disks, not the shared disks which were presented to the VMs as RDM. I first read a few articles: VMware KB article on RDM storage vMotions
An article from Scott Lowe
An article from Joep Piscaer, a former colleague of mine, definitely a recommendation to read!
VMware KB article on Microsoft clustering support
Now, all of these articles are great but they didn't specifically describe my situation. Because for Microsoft Clustering, you need a separate SCSI controller for your RDM disks with physical SCSI BUS sharing, to make sure you can share the disks between VMs on different hosts:
| SCSI Bus Sharing policy | Description |
|---|---|
| None | Virtual disks cannot be shared between virtual machines |
| Virtual | Virtual disks can be shared between virtual machines on the same server |
| Physical | Virtual disks can be shared between virtual machines on any server |
Also note the support for the actual SCSI controller. I'm a big fan of the paravirtual SCSI controller but that one is not supported for Microsoft Clustering:
The shared storage SCSI adapter for Windows Server 2008 must be the LSI Logic SAS type, while earlier Windows versions must use the LSI Logic Parallel type.
So I had to test what happens with a RDM disk while in virtual and in physical compatibility mode to come with an answer on what is the best migration method.