Monday Mar 17, 2008

SAM-QFS Code Open Sourced

We are please to announce that we have open sourced the SAM-QFS code! This major contribution to the OpenSolaris community is available on We are very excited to take this big step in creating an open source community around SAM-QFS and continuing to grow Open Solaris as a premier storage OS.

So, I'd like to explain where we are today and where we are going relative to posting the source. Getting all of the Sun SAM-QFS IP posted for Community viewing and download was priority number one. This announcement is about that first milestone. We are looking forward to connecting with developers, early adopters, and users through our open source effort. Eventually we plan to externalize the source via Mercurial to facilitate community code contributions.

What we are delivering is our current development source. Our goal is to have the community be part of the development process, so we are intentionally posting our development work instead of released software, such as the SAM-QFS 4.6 code. By delivering development source, the community can influence and contribute to development of future releases, and it allows early adopters to quickly get access to the latest features. This change should benefit not only the future SAM-QFS releases and therefore customers. In addition, it will benefit those that would like to adopt or experiment with Solaris as a storage platform.

This initial post is a gzipp'd tarball of our latest development build. Some third party components were removed for legal reasons. Therefore, this first posting won't build unless the missing third party components are added back or coded around. This is a temporary solution until we either get legal permission to post the third party source or recode those sections so that they can be built with or without the third party components.

We look forward to feedback about what we have posted and what you as the SAM-QFS community would like to see in future source code uploads. To that end, we have two discussion lists for communication.

1) SAM-QFS-DISCUSS - The discussion list for general topics or issues

2) SAM-QFS-DEV - The development alias for specific questions about source, source contributions, or code reviews

Again, please join us at the OpenSolaris SAM-QFS project page ( We look forward to your comments and involvement.

'til next time, Ted

Thursday Mar 06, 2008

Development update: Archiver

We are actively working on the archiver to improve SAM scalability and performance. One area we are focusing on is reducing the scanning and therefore metadata footprint of the archiver. Currently, the noscan method of the archiver gathers inode (file) events to determine whether and when an inode needs to be archived. After receiving the event, the archiver schedules a scan of the associated directory. The list of directories to be scanned become the archiver's worklist. We are working to improve archiver performance by changing the sam-arfind daemon's worklist from a list of directories requiring scanning (in order to find files requiring examination), to the actual list of file inodes requiring examination.

Keeping the actual list of inodes should significantly reduce the frequency scans done by the archiver. In general, most inode events would require examination within minutes or hours. However, for those longer time frame examinations, only those files that need to be examined within a "rolling window" of time are kept in the worklist. The duration of the "rolling window" is specified by the 'background_interval' in the archiver.cmd file. The default might be 24 hours. Files that require examination after this time will be found during the next background scan. The time of day for the background scan is specified by the 'background_time' in the archiver.cmd file. The default might be (midnight). The intent of these tunables is to allow the administrator to schedule the background scans at a frequency and time that minimizes archiver scan impact to production.

'til next time, Ted

Wednesday Mar 05, 2008

New 4.5 and 4.6 patches released

The 4.6-04 patch and the 4.5-06 patch are now available for download. In addition to the usual bug fixes, we added quite a bit of new support in the 4.6-04 patch.

Newly Qualified with SAM-QFS 4.6-04

1) The Sun StorageTek 5800 System Version 1.1 is supported with SAM-QFS.

2) The HP LTO4 tape drive is now qualified with SAM.

3) ACSLS 7.2 is now qualified with SAM-QFS.

4) The Sony Super AIT2 tape drive is now qualified with SAM-QFS.

5) The HP SL48 library is now qualified with SAM-QFS

6) The Sun VTL and the following drives are now qualified with SAM-QFS: HP LTO3 IBM LTO3 STK 9940C STK 9840B STK T10K

7) Intel EM64T 64 bit architecture servers are supported with SAM-QFS, including SAM and Shared QFS MDS on Solaris 10 and Shared QFS clients on Solaris 10, Red Hat 4, and SLES 10 OSs.

Here is the link to the wiki:


    'til next time, Ted

  • Friday Jan 25, 2008

    Development update: Journaling

    We are forging ahead with development of the next SAM-QFS release. Although, I cannot make any promises about features (This is software development after all), I wanted to provide a peek at some of our feature development. I'll try to provide these updates on a regular basis. I hope you find these useful.


    One of the features we are working on is journaling. Some of the benefits of jounaling to QFS are reduced need for samfsck and increased metadata performance. While QFS has a consistency model that generally does not require an fsck, except to reclaim lost space and clean up orphan inodes, journaling will reduce the need for this type of clean up after a panic. The bigger benefit to QFS is the increase in metadata performance. Journaling can reduce the frequency of disk accesses required for metadata-intensive applications. This boosts the performance of QFS. In some preliminary tests, we have already seen a significant increase in performance on Shared QFS clients with journaling enabled on the metadata server. I'll try to report some real numbers as development progresses.

    'til next time, Ted

    Wednesday Dec 12, 2007

    New SAM-QFS patch released for download

    We recently released the third 4.6 patch (4.6-03). A few items that I think are exciting support additions in this patch, on top of the usual bug fixes.

    1) 256 node support for Fibre Channel.

    \* This is part of our continuing effort to increase the scalability of Shared QFS. This should be welcome news for those customers already running 128 nodes and looking to increase node count. It also enhances Sun's HPC file system offering for small to mid size customers.

    2) New tape drive and library qualifications.

    \* The Sony CSM-20S library has been qualified for use with Sun StorageTek SAM-QFS 4.6 Patch 03. The device type is 'cs'. The import command in SAM for CSM-20S library imports one tape at a time.

    \* The IBM LTO4 tape drive has been qualified for use with Sun StorageTek SAM-QFS 4.6 Patch 03. The device type is 'li'. Although no changes are required in /kernel/drv/st.conf for SAM support of the IBM LTO4 drive, the latest st patch is required.

    \* The Quantum DLT-S4 tape drive has been qualified for use with Sun StorageTek SAM 4.6 Patch 03. The device type is 'lt'. Although no changes are required in /kernel/drv/st.conf for SAM support of the DLT-S4 drive, the latest st patch is required.

    3) New server architecture support \* Intel EM64T 64 bit architecture servers are supported with Shared QFS

    Also, take a look at our new Wiki for more information on 4.6. It provides a growing wealth of technical information on SAM-QFS releases, including a patch download link, documentation, a growing faq, and more. Here is the link to the wiki:


    Lastly, we are still forging ahead with our open source plan. We've started a discussion alias "" and added the source for sdu, sls, sfind, and star to the existing Libsam code. Expect more code in the coming months. I also encourage you to join the discussion alias and become part of the community. Here is the link to the open source page


    'til next time, Ted

  • About

    Ted Pogue


    « July 2016