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Storage and Availability Management
Showing posts tagged with Storage Foundation
Showing posts in English
Rishi Manocha | 10 Mar 2009 | 1 comment

A group of DBAs that manage large databases at a large federal government agency had the challenge of migrating a mission-critical 35 TB database from a Fujitsu 2500 running Solaris to an IBM P595 running AIX within a 4 hour maintenance window. Using the tools that the database vendor offered, the estimated time to move that much data was in the neighborhood of 3 weeks, which was unacceptable. Database migration tools from another company were evaluated but they were cost prohibitive.

A Symantec Sales Engineer suggested that these DBAs use the Portable Data Container (PDC) feature within Storage Foundation, which was already deployed in their infrastructure. He explained that with PDC, instead of moving the data from one storage location to another, the data can be unmounted from the Solaris system and mounted on the AIX system. The entire process would take no more than 30 minutes.

The PDC feature was tested in the customer’s lab environment and was put in...

davidnoy | 07 Jan 2008 | 0 comments
Please find the scalabiltiy white paper which was refered to in the previous post here:
davidnoy | 12 Dec 2007 | 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 | 12 Dec 2007 | 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 | 06 Aug 2007 | 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'...

Ameya | 03 Aug 2007 | 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 | 17 Jul 2007 | 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...

Mandar Bhide | 18 Jun 2007 | 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 | 13 Apr 2007 | 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...

Ameya | 02 Apr 2007 | 0 comments

The Dynamic Multi Path (DMP) capability was first introduced in Volume Manager 2.5.7 release primarily to support A/A multi path arrays from Sun Microsystems. In those days, the early version of arrays had SCSI connections with fat and thick cables running from host to the array directly. Unlike the present day modern arrays, there was no concept of fabric switches, and no fiber channel (FC) technology enabled on the arrays. The first DMP could do only multi path operations such as load balancing using balanced path I/O policy, path failures and restoration by using SCSI inquiry commands. Since the number of devices were handful, the error processing and restore processing were all single threaded tasks. Further, as the number of supported arrays was small, the entire device discovery and reconfiguration was closely tied to the parent operating system.

The next major enhancements of DMP were introduced in Volume Manager 3.1.1 release that had support to co-exist with...