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Storage & Clustering Community Blog

Showing posts tagged with Storage Foundation
Showing posts in English
Kimberley | 03 Mar 2009 | 1 comment

Welcome to the Storage Management section of Symantec Connect! If you're coming here from the former Symantec Technology Network (STN) site, this may look pretty different. Connect is a new site, combining STN, Altiris Juice and the Altiris Technical Support Forums under one roof, along with a bunch of cool new features. To introduce myself, I'm Kimberley Bermender (username Kimberley), and I’ll be managing and modering the content for this section. Feel free to drop me a note if you have any questions, comments, suggestions or ideas.

While there’s a lot that’s new here, you’ll find familiar content from the STN Storage Foundation forums (Database Edition for Oracle, Storage Exec, Storage Foundation Family, Veritas Installation Assessment Service, Volume Manager, CommandCentral and Virtual Infrastructure), as well as articles that have all been migrated. There’s also a lot of new Storage content that the Development team has created, including...

Kimberley | 08 Apr 2009 | 0 comments

Written by: Thomas Cornely

What’s the Hardware Zero Reclaim functionality?  It basically refers to the array’s ability to scan a thin lun and look for pages of physical storage that contain ‘all zeroes’. When they find such a page, they reclaim the page (i.e. detach it from the thin lun) and put it back in the free pool. They can do this because the array returns ‘0’ to any I/O read it received on ‘unallocated space’ in a thin lun.

Who’s doing it?

Most hardware vendors are coming out with similar functionality. IBM XIV was the first one to have it. 3PAR has it. NetApp has it (they actually have true dedup in the array). Now Hitachi has it.

What are limitations of the Hardware Zero Reclaim functionality?

Hardware Zero Reclaim relies on the presence of 0 in the array to do the reclamation. In the context of a thick to thin migration, the process would be as follows:

  • start with 1...
davidnoy | 05 Mar 2010 | 0 comments
Please find the scalabiltiy white paper which was refered to in the previous post here:
 
 
davidnoy | 05 Mar 2010 | 1 comment
 
 
 
 
 
 
 
The question: Is CFS scalable? What performance hit is there from running VxFS in a clustered configuration?
 
Often times in sales situations, we are asked what the performance implications are of running CFS.
 
Customers are eager to know what the performance hit would be from operating in a clustered environment. This is particularly interesting to customers who are considering deploying our CFS HA solution as an upgrade to the regular Storage Foundation HA solution. They want want to know what CFS is going to cost in performance, and so did we.
 
The test: Run a workload on 1, 2, 4, 8, and 16 nodes and measure throughput.
 
With the outstanding efforts of the Performance Enigneering Group, we were able to measure...
davidnoy | 05 Mar 2010 | 0 comments
 
 
 
 
Hello all! Welcome to the Cluster File System blog.
 
 
This blog will serve as a sounding board for engineering and product management to discuss their views on cluster file systems:
 
  • What are they good for?
  • Where do we feel they can provide the most benefit?
  • What are some of the interesting use cases we have seen?
  • What notable improvements have we made in our product?
  • Where do we see the technology going? How would we like to shape the future of CFS?
 
The first entry will discuss some of our recent scalability findings which will be published shortly in both the form of a white paper and a press release. We are very excited about the results. So please, read on...
 

Message Edited by davidnoy on 12-12-2007 05:45...

charmer | 05 Mar 2010 | 3 comments

Last week Symantec published some benchmark results comparing Storage Foundations and ZFS that suggest VxFS is around 3 times faster than ZFS for workloads  typical of many commercial applications.  These results  contrast sharply with some benchmark results published by Sun which  suggest that VxFS is about 1/3 the speed of ZFS.

I'm sure this is going to leave a lot of people scratching their heads and asking "how can the results be so different?".   The complete answer to that question is quite long, but I can try to offer a summary.  Unfortunately, that will leave out many important details.  I hope to address those in another article.

The short answer is that Symantecs' results are based...

Ameya | 10 Dec 2010 | 1 comment
Array Policy Module (APM)

=====================

The APM framework was introduced in Volume Manager 4.0 release. The 4.0 release brought about a major change in DMP architecture - the introduction of APM. As the name suggests, the Array Policy Module (APM) is specific to an array type and defines the policies for an array type. Analogous to its Array Support Library (ASL) counterpart in user space which enables the DDL to identify the array completely, the APM enables DMP kernel to perform array specific operations such as failover, NDU (Non-Disruptive Upgrade), STPG (Set Target Port Groups) and even an I/O policy.

The APM makes it possible for DMP to dynamically add kernel support for an array. The support for enabling an APM is completely online and does not require a reboot. An APM is essentially a dynamically loadable kernel module that is validated and loaded by DMP whenever DMP detects the array type support exported by that APM. In other words, the DDL...

charmer | 05 Mar 2010 | 7 comments
Some engineers at Sun promoting ZFS have been publishing comparisons between VxFS and ZFS that are rather unflattering to VxFS. You can read the most recent white papers they've published comparing ZFS with VxFS, ext3, and Window's NTFS as well as some blog entries comparing the performance of VxFS and ZFS.

The comparisons with VxFS appear to be objective, but in fact the performance comparisons are chosen quite selectively. In addition, the most recent white paper contains a few significant errors.

Going through the most recent white paper from beginning to end, the first thing to strike me were some significant errors in the discussion of file system scalability.  Errors include the...

Mandar Bhide | 05 Mar 2010 | 0 comments
Storage capacity requirements are growing at an explosive rate, complicating data and storage management in mission-critical and compliance-driven environments. Enterprises need to securely store more information and more information types. Data must be safely secured and available for rapid recovery in the near term, while also meeting long-term archival and compliance regulations. These complex issues have created a variety of manageability, storage availability and price performance challenges, ranging from missed service levels to operational risks.
 
Recent industry trend reports by analysts show that the IT budgets are growing at six percent a year; but data under management is growing between 50 and 70 percent or more. Keeping up with data growth while reducing the cost of data management, requires deep analysis and an understanding of underlying storage delivery infrastructure.
 
To ensure the financial benefits...
Ameya | 10 Dec 2010 | 1 comment

The first basic function for a multi path (MP) driver is to identify the set of block devices that can be supported. The device discovery is generally triggered when the MP driver is loaded into the operating system (OS) as part of boot process. During early boot, not all devices connected to the system may be available. For example, the devices connected using the fibre channel (FC) cables may not be available during early boot time unless there is special support from the bootstrap, which is usually from NVRAM or EEPROM, to identify the fibre channel devices. In any case, it may be required for a MP driver to rescan the OS device tree at a later stage of boot process.

One of the biggest challenges in device discovery is the ability and skill of MP driver to discover disk devices and their attributes in a non-intrusive fashion such that the disk media is not touched. In other words, the device discovery has to be purely read-only operations to identify the disk and disk...