AIX or Linux on POWER?
cggibbo 270000TMUJ Comments (8) Visits (33368)
IBM made some announcements today relating to their latest POWER7 server offerings. The new line of systems includes new entry level systems and the highly anticipated high-end system, the POWER7 795! They also officially outlined some of the new features available in AIX 7.1. You can review the details here. I’ve discussed some of these new features here and here. The official AIX 7.1 announcement details are available here.
The announcement got me thinking about my recent customer engagements and why some have chosen to deploy AIX into their IBM POWER environments, while others are considering a Linux on POWER solution.
I’ve found that it usually comes down to a skills decision more than anything else. Most customers are happy to either continue working with AIX (if they are existing AIX users) or migrate from another UNIX OS to AIX. I’ve seen very few customers actually migrate to Linux on POWER, but I’ve worked with several that have seriously considered it. Those that have chosen to deploy Linux are doing so purely because they have in-house Linux skills. They are concerned that migrating to AIX may be too big a jump for their technical staff. I find this thinking interesting, as most of the customers I’ve dealt with who run other UNIX OS’s like Tru64, Solaris or HP-UX are more than happy to migrate to AIX. They believe the move is relatively minor and doesn’t require massive re-training of their UNIX admins. I tend to agree.
For me, AIX is my preferred “Enterprise class” UNIX Operating System. Notice I’m prefacing this with the words Enterprise class. Don’t get me wrong, I have worked with Linux systems in both small and large customer environments. It is a great OS. But I’ve found that it really only fits into environments that have a relatively small number of users and where significant downtime can be tolerated for things like operating system maintenance. This doesn’t fit the Enterprise class of UNIX server OS’s that I’m thinking of here. When I contemplate the word Enterprise, I think of servers and operating systems that can respond to business demands in terms of performance, reliability, stability and availability. An Enterprise UNIX can provide all of these things without compromise. Linux can offer performance and reliability (in my opinion). However, from what I’ve seen, it lacks features & functions in the areas of stability and availability. AIX on the other hand ticks all the boxes. Again, this is just my opinion based on my experiences with both AIX and Linux in the Enterprise landscape. Others will no doubt have their own experiences that may or may not match my own.
So when I’m designing an Enterprise UNIX server environment for a customer, I always start with an AIX on POWER base. If the customer wants Linux, sure I can look at that too, but I strongly recommend AIX as my preferred choice for large systems. Most of my customers are running relatively large SAP/Oracle systems. AIX on POWER is a great combination for large Enterprise systems. If you need to deploy large database systems that must service tens of thousands of users (like a big SAP system), then I believe AIX is the perfect OS on which to provide a platform for these large scale systems.
AIX is a very mature and powerful UNIX OS. It has been a major player in the UNIX server market for over 20 years (as shown below). Some people are just not aware of how mature, robust and stable the AIX OS has become over the years. There are many impressive aspects of the OS in the areas of performance, scalability, reliability, management and administration.
Just looking at some of the administration capabilities built into AIX are enough for me to always recommend AIX over Linux (or any other UNIX OS), when it comes to large Enterprise servers.
For example, the System Management Interface Tool (SMIT) can make the UNIX admins life a lot simpler. This is an interactive tool that is part of the AIX OS. Almost all tasks that an AIX administrator may need to perform can be executed using this tool. It is a text-based tool (there is also an X interface but I recommend sticking with the text-based menus). Everything it does, it does through standard AIX commands and Korn shell functions. This feature is especially useful when you need to automate a repetitive task; you can have SMIT create the proper command-line sequence, and you can then use those commands in your own script. My compatriot, Anthony English, has a nice intro to SMIT on his AIX blog.
The AIX Logical Volume Manager (LVM) is built into the OS, for free. AIX LVM helps UNIX system administrators manage their storage in a very flexible manner. LVM allows logical volumes to span multiple physical volumes. Data on logical volumes appears to be contiguous to the user, but might not be contiguous on the physical volume. This allows file systems, paging space, and other logical volumes to be resized or relocated, span multiple physical volumes, and have their contents replicated for greater flexibility and availability. It provides capabilities for mirroring data across disks, migrating data across disks & storage subsystems, expand/shrink filesystems and more.......all of which can be performed dynamically.....no downtime required. The concept, implementation and interface to the AIX LVM is one of a kind. All of its features support the ‘continuous availability’ philosophy.
One of the biggest reasons that I love AIX over Linux is the mksysb. It’s built into the OS and allows you to create a bootable image of your AIX system. This image can be used to restore a broken AIX system or for cloning other systems. The cloning feature is truly amazing. You can take an image created on a low-end system and deploy it on any POWER system, all the way up to the high-end POWER boxes. This simplifies the installation and cloning processing when you need to install and manage many AIX LPARs. By using an SOE mksysb image you can deploy consistent AIX images across your Enterprise POWER server environment.
This brings me to another wonderful feature of AIX, the Network Installation Manager (NIM). NIM is powerful network installation tool (comparable to Linux Kickstart). Using NIM you can backup/restore, update and upgrade one or more AIX systems either individually or simultaneously. This can all be achieved over a network connection, removing the need for handling physical installation media forever.
Another fine example of AIXs superior OS management tools is multibos. This tool allows an AIX administrator to create and maintain two separate, bootable instances of the AIX OS within the same root volume group (rootvg). This second instance of rootvg is known as a standby Base Operating System (BOS) and is an extremely handy tool for performing AIX TL and Service Pack (SP) updates. Multibos lets you install, update and customize a standby instance of the AIX OS without impacting the running and active production instance of the AIX OS. This is valuable in environments with tight maintenance windows.
When it comes to upgrading the OS to a new release of AIX, the nimadm utility can assist the administrator greatly in this task. The nimadm utility offers several advantages. For example, a system administrator can use nimadm to create a copy of a NIM client's rootvg and migrate the disk to a newer version or release of AIX. All of this can be done without disruption to the client (there is no outage required to perform the migration). After the migration is finished, the only downtime required will be a single scheduled reboot of the system.
AIX 6.1 introduced new capability that most UNIX operating systems are still working on. Concurrent Updates of the AIX Kernel.....without a reboot! IBM is always working hard at making AIX an OS that can provide continuous availability, even if it needs to be patched. AIX now has the ability to update certain kernel components and kernel extensions in place, without needing a system reboot. In addition, concurrent updates can be removed from the system without needing a reboot. Can you do this with other UNIX OSs?
And that’s just some of the features that make AIX the only UNIX OS that I recommend for Enterprise systems. There are many more tools and features that I couldn’t live without (like alt_disk_install, savevg, installp, WPARs, etc, the list goes on). If you are new to AIX and you are considering what your next UNIX OS should be, then I recommend you take a very close look at AIX.
And finally, the support provided by IBM, is first class. Whenever I’ve needed assistance with an AIX issue or query, I have always received timely, professional and useful advice. On the rare occasions where I’ve uncovered a new bug, IBM AIX support have always been quick to provide me with an interim fix to resolve or workaround a problem. That’s the sort of support you’d expect for an Enterprise UNIX OS, isn’t it? What’s the support like from your current UNIX (or Linux) OS vendor?
Linux is still a viable UNIX operating system. However, I think it’s more suited to certain workloads like small to medium size mail, web and other utility servers and services. AIX, however, would be my platform of choice for my 10TB Oracle database running SAP ERP, not just for performance reasons, but primarily because of the system administration features of AIX that allow me to support and manage the system without impacting my customers or enforcing reboots/outages whenever I need to change something on the system.
All IBM need to do is create their own Linux distribution (Blue Linux perhaps?) that has all the features of AIX built in and then I’m sold! But why would they? We already have AIX.
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