Topic: DTrace Deep Dive and a short talk on LDOM Domains and ZFS

When:
Burlington MA Sun Campus – Feb 2, 2010 6:00PM to 9:00 PM
Boston MA – Boston University – Feb 3, 2010 6:00PM to 9:00 PM
(Note: The same content will be presented twice – once in Burlington and once in Boston. Pick the best location and date as convenient.)

Where:
Feb 2 – Sun Microsystems Burlington Campus; 1 Network Drive, Burlington, MA
Feb 3 – Boston University, Electrical and Computer Engineering Department Photonics Center Building – Room PHO 339 (3rd floor), 8 Saint Mary’s Street Boston, MA 02215
BU Parking: Street parking available on St. Mary’s Street and Bay State Road. Metered parking spots do not require a fee after 6pm.

RSVP: To Linda Wendlandt: lwendlandt@cptech.com

Registration Required! – so we can plan food and drink

Join Jim Mauro and Shannon Sylvia for how-to DTrace, and how to use LDOMs with ZFS.

AGENDA:

6:00-6:20: Registration, Pizza and Beverages

6:20-6:30: Introductions: Peter Galvin, CTO, Corporate Technologies

6:30-8:30: Solaris Dynamic Tracing – DTrace – Jim Mauro, Principle Engineer, Sun Microsystems

8:30-9:00: LDOM Domains and ZFS: An example of creating a ZFS bootable root LDOM domain using jumpstart – Shannon Sylvia, Sysadmin, Northeastern University

9:00 Q&A and Discussion

Also we’ll be giving out official NEOSUG T-Shirts and other trinkets, and copies of the OpenSolaris CD and instruction manual.

For more information see the NEOSUG discussion forum.

I have received a few questions relating to my previous post about NetApp VMware bootstorm results and want to answer them here.  I have also had a chance to look through the performance data gathered during the tests and have a few interesting data points to share. I also wanted to mention that I now have a pair of second generation Performance Accelerator Modules (PAM 2) in hand and will be publishing updated VMware boot storm results with the larger capacity cards.

What type of disk were the virtual machines stored on?

• The virtual machines were stored on a SATA RAID-DP aggregate.

What was the rate of data reduction through deduplication?

• The VMDK files were all fully provisioned at the time of creation. Each operating system type was placed on a different NFS datastore. This resulted in 50 virtual machines on each of 4 shares. The deduplication reduced the physical footprint of the data by 97%

A few interesting stats gathered during the testing. These numbers are not exact and due to the somewhat imprecise nature of starting and stopping statit in synchronization with the start and end of each test.

• The CPU utilization moved inversely with the boot time. The shorter the boot time, the higher the CPU utilization. This is not surprising as during the faster boots, the CPUs were not waiting around for disk drives to respond. More data was served from cache the the CPU could stay more utilized.
• The total NFS operations required for each test was 2.8 million.
• The total GB read by the VMware physical servers from the NetApp was roughly 49GB.
• The total GB read from disk trended down between cold and warm cache boots. This is what I expected and would be somewhat concerned if it was not true.
• The total GB read from disk trended down with the addition of each PAM. Again, I would be somewhat concerned if this was not the case.
• The total GB read from disk took a significant drop when the data was deduplicated. This helps to prove out the theory that NetApp is no longer going to disk for every read of a different logical block that points to the same physical block.

How much disk load was eliminated by the combination of dedup and PAM?

• The cold boots with no dedup and no PAM read about 67GB of data from disk. The cold boot with dedup and no PAM dropped that down to around 16GB. Adding 2 PAM (or 32GB of extended dedup aware cache) dropped the amount of data read from disk to less that 4GB.

The news of Sun integrating an in-line deduplication feature into ZFS has created quite a buzz in storage circles. And our clients have been asking us about how to gain access to this new feature. This blog post describes the steps needed to build an OpenSolaris server, integrate the deduplication feature, and enable it.

For details about the ZFS deduplication feature, what it does, and how it does it, have a look at Jeff Bonwick’s blog post on the topic. He was the lead engineer on the project so you can take his word on it.

Deduplication was integrated into OpenSolaris build 128. That takes a little explanation. Solaris is Sun’s current commercial operating system. OpenSolaris has two flavors – the semiannual support-able release, and the frequently-updated developer release. The current supportable release is called 2009.06 and is available for download here. Also at that location is the “SXCE” latest build. That distribution is more like Solaris 10 – a big ol’ DVD including all the bits of all the packages. OpenSolaris is the acknowledged future of Solaris, including a new package manager (more like Linux) and a live-CD image that can be booted for exploration, and installed as the core release. To that core more packages can be added via the package manager.
Read more…

The OpenSolaris security team has added an interesting proof of concept feature. Immutable Service Containers are designed to make building, configuring, and recreating pre-secured containers easier. The net result, if incorporated into OpenSolaris and eventually a future version of Solaris, should be a set of security best practices managed via a feature-rich framework. Between now and then, there is quite a bit of work for the team to do. My December 2009 column in ;login: Magazine discusses the design goals and current state of Immutable Service Containers. Members of USENIX can read it on-line, while others can download it here:

  2009-12-column.pdf (269.0 KiB)

There is still time to register for the  VMware vs. Hyper-V Hands-on Workshop we are holding on Wednesday, November 18th, at the Hilton Boston/Woburn hotel in Woburn, MA.

The workshop will begin at 8:30 am and includes lunch. During the workshop John Laferriere will present a quick overview of Corporate Technologies. Next I will present a talk based on our VMware vSphere 4 vs. Hyper-V R2 white paper. Next Sean Daly and Joe Gries will do hands-on demonstrations of the two technologies. This will be followed by Q&A and lunch.

We are encouraging attendees to ask us about specific use cases and solution requirements to optimize the value of the workshop.  For more details and to register please see the invitation.

(Sorry for the short notice… hope you can join us)

Topic: An Introduction to OpenSolaris and its Uses

When: November 11, 2009 6:00PM to 9:00 PM

Where: Boston University, Electrical and Computer Engineering Department Photonics Center Building – Room PHO 339 (3rd floor), 8 Saint Mary’s Street Boston, MA 02215 http://www.mapquest.com/maps?&city=boston&state=ma&address=8%20st.%20mary%27s%20street

Parking: Street parking available on St. Mary’s Street and Bay State Road. Metered parking spots do not require a fee after 6pm.

RSVP: To Ayse Kivilcim Coskun (acoskun at bu dot edu)

Registration Required! – so we can plan food and drink

Join Brian Leonard, Bogdan Vasiliu, Ayse Coskun, and Peter Galvin for an overview of OpenSolaris and its uses.

AGENDA:

6:00-6:20: Registration, Pizza and Beverages

6:20-6:30: Introductions: Peter Galvin, CTO, Corporate Technologies

6:30-8:00: What’s So Cool About OpenSolaris Anyway – Brian Leonard, Technology Evangelist, Sun Microsystems

8:00-8:30: OpenSolaris: Clusters and Clouds from your Laptop – Bogdan Vasiliu, Solaris HPC, Sun Microsystems,Inc.

8:00-8:30: Presentation: Solaris containers – Peter Galvin, CTO – IT Architecture, Corporate Technologies

8:30-8:45: OpenSolaris as a Research and Teaching Tool – Ayse K. Coskun, Assistant Professor Electrical and Computer Engineering Department, Boston University

8:45-9:00 Q&A and Discussion

- Also we’ll be giving out official NEOSUG T-Shirts and other trinkets, and copies of the OpenSolaris CD and instruction manual.

For more information please see the full announcement in the NEOSUG forum.

There is a bug that has been hit by one of our clients and we wanted to post a quick alert before other sites implement the change that causes this problem.

The problem is only of concern to sites running Sun Solaris and using the IP Multipathing facility – using multiple ethernet connections bundled together for availability and performance.

Here are the details of the problem:

There is an issue with IPMP failures (Probe based detection only) due to a kernel patch (141444-09 {SPARC} and 1414450-09 {x86}) found in the latest Solaris 10 Recommended Patch Cluster (Released 10/21/09).

See Patch Cluster ReadMe for additional details on patch contents.

The included kernel patch causes failures with IPMP Probe Based Failure Detection IPMP Groups, which is what we frequently use when deploying best practices standalone systems as well as SunCluster based systems. The problem can be confirmed by snooping the FAILED interface for outgoing ICMP probe packets that should exist but don’t, due to the bug caused by the kernel patch. Instead, the active interface that hasn’t failed will be sending and receiving ICMP probe packets using both configured IPMP group test IP address.

The details of the problem are in this bug document:
http://sunsolve.sun.com/search/document.do?assetkey=1-66-271519-1 <http://sunsolve.sun.com/search/document.do?assetkey=1-66-271519-1>

Sun is recommending that the patch cluster (and the specific patch) not be backed out and remain in place because of security fixes it addresses.

Customers using probe based IPMP groups that require stability (and probe based IPMP failure detection) rather than security are best to avoid this Patch Cluster. Customers needing the security protection due to either operation within a hostile environment or compliancy requirements will need to convert their probe based IPMP groups to link based IPMP groups prior to applying the new Patch Cluster. This will reduce the effectiveness of the IPMP failure detection, but will allow the IPMP groups to remain functional until Sun addresses the issue.

We will continue to monitor this issue until resolution is announced, and will post updated information here.  Thanks to Corporate Technologies’ solution architect Ed Hamilton for detecting this problem and writing up the details.

UPDATE: I have posted an update to this article here: More boot storm details

Measuring the benefit of cache deduplication with a real world workload can be very difficult unless you try it in production. I have written about the theory in the past and I did a lab test here with highly duplicate synthetic data. The results were revealing about how the NetApp deduplication technology impacts both read cache and disk. Based on our findings, we decided to run another test. This time the plan was to test NetApp deduplication with a VMware guest boot storm. We also added the NetApp Performance Accelerator Module (PAM) to the testing.

The test infrastructure consists of 4 dual socket Intel Nehalem servers with 48GB of RAM each. Each server is connected to a 10GbE switch. A FAS3170 is connected to the same 10GbE switch. There are 200 virtual machines: 50 Microsoft Windows 2003, 50 Microsoft Vista, 50 Microsoft Windows 2008, and 50 linux. Each operating system type is installed in a separate NetApp FlexVol for a total of 4 volumes. This was not done to maximize the deduplication results. Instead we did it to allow the VMware systems to use 4 different NFS datastores. Each physical server mounts all 4 NFS datastores and the guests were split evenly across the 4 physical servers.

The test consisted of booting all 200 guests simultaneously. This test was run multiple times with the FAS 3170 cache warm and cold, with deduplication and without, and with PAM and without. Here is a table summarizing the boot timing results. This is the amount of time between starting the boot and the 200th system acquiring an IP address. Here are the results: Read more…

There are many, many choices available when it comes to virtualization technologies. Even within server virtualization, there are many options. Once the choices have been narrowed, it is still a chore to wade through the options and limitations to determine the best fit for a given datacenter environment.

Some frequent decision points include:

• Is your environment large enough to bother virtualizing?
• If you are running VMware, should you consider Microsoft Windows Server 2008 Hyper-V R2?
• Can Hyper-V run other guest operating systems?
• What should a Windows-only shop do?

To help ease the effort, we’ve created a decision flow chart involving the two contenders on the short list at most sites – VMware vSphere 4 and Microsoft Hyper-V R2. This chart starts from your current infrastructure and leads you through the important decisions, and to the conclusions you are likely to reach.

The chart is based on much more detailed information provided in our vSphere vs. Hyper-V whitepaper available for download in this blog posting as well as the associated talk available here.

Hopefully this chart will help you make your server virtualization decisions. Please get in touch if you would like to review the whitepaper or have us evaluate the virtualization options for your datacenter. (Please click on the image for a full-size view.)

I have migrated some data to ZFS filesystems recently and the capacity consumed has surprised me a couple times. In general, it has appeared that the data uses more capacity when stored on the ZFS filesystem. This prompted me to do a little investigating. Is ZFS using more capacity? Is it simply a reporting anomaly? Where is that space going? Does ZFS record size have a major impact? Does enabling compression have a significant impact?

In part, the extra space use is a result of ZFS reporting space utilization differently than other filesystems. When a ZFS filesystem is formatted, almost no capacity is used. A df command will show nearly the entire raw capacity. Many other filesystems take a portion of the raw capacity off the top and reserve it for metadata. This reserve will not show up in df. As data is added to the ZFS filesystem, blocks are allocated for both data and metadata. Both the data and metadata blocks will show up as used capacity. In many other filesystems, at least some of the metadata blocks will be taken from the reserve and only the data blocks will show as consumed capacity. For example, in Solaris, the du command will return the capacity used by the data blocks in a file. In ZFS, that du command returns the total space consumed by the file including metadata and compression. So the question at hand is, when storing a given set of files, does ZFS use more total space than other file systems? That one is difficult to test, given all the variables. But we can test various ZFS configuration options to determine the best settings for minimizing block use.

Read more…