Oracle Clusterware 10g will always handle node fencing (aka eviction) by rebooting one or more nodes. Oracle didn’t have its own cluster manager software for most platforms on 9i. So, if your customer was on a platform where Oracle didn’t have a cluster manager of its own (it only had a Linux and Windows), then building the RAC cluster would have required some 3rd party software. Some of the 3rd party cluster managers used different schemes to fence nodes from the cluster. Many of them used I/O fencing which is less disruptive in that it didn’t require a node reboot, but required more proprietary interfaces to be used to access and manage storage.
I/O Fencing, or simply fencing, gives write access to members of the active cluster and blocks access to non-members. The physical components of I/O fencing in Storage Foundation for Oracle RAC are coordinator disks and data disks. Each component has a unique purpose and uses different physical disk devices.
Data disks are standard disk devices for data storage and are either physical disks or RAID Logical Units (LUNs). These disks must support scsi-3 PR and are disks or RAID Logical Units (LUNs). These disks must support SCSI-3 PR and are part of standard VxVM/CVM disk groups.
CVM is responsible for fencing data disks on a disk group basis. VxVM enables I/O fencing and provides additional features. Disk added to a disk group are 14 VERITAS Storage Foundation for Oracle RAC Installation and Configuration Guide.
Coordinator disks are three (or an odd number greater than three) standard disks or LUNs set aside for I/O fencing during cluster reconfiguration. These disks provide a lock mechanism to determine which nodes get to fence off data drives from other nodes. A node must eject a peer from the coordinator disks before it can fence the peer from the data drives. This concept of racing for control of the coordinator disk to gain the ability to fence data disks is the key to understanding prevention of split brain through fencing.
Coordinator disks do not serve any other purpose in the Storage Foundation for Oracle RAC configuration. Users cannot store data on these disks or include the disks in a disk group for user data. The coordinator disks can be any three disks that support SCSI-3 PR. VERITAS recommends using the smallest possible LUNs for coordinator disks. Since coordinator disks do not store any data, cluster nodes need only register with them and do not need to reserve them.
I/O fencing provided by the kernel-based fencing module (VXFEN), performs identically on node failures and communications failures. When the fencing module on a node is informed of a change in cluster membership by GAB module, it immediately begins the fencing operation. The node attempts to eject the key for departed node(s) from the coordinator disks using the preempt and abort command. When the node successfully ejects the departed disks, in a split –brain scenario, both sides of the split would race for control of the coordinator disks. The side winning the majority of the coordinator disk wins the race and fences the loser. The loser then panics and reboots the system.
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Uncategorized
Article originally posted on GovDesignHub here.
Autodesk University (AU) returns to Las Vegas from November 19-21 – and we have some good news. In addition to discounted conference passes now available on GSA Schedule, Autodesk Certification exams are back at AU 2019!
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Uncategorized
By Mav Turner, VP, Product Management, SolarWinds
For federal IT pros, moving to a cloud environment is a “when” rather than an “if” proposition. From the government’s recently released Report on IT Modernization, calling for agencies to identify solutions to current barriers regarding agency cloud adoption, to the White House’s draft release of a new “Cloud Smart” policy, which updates the “Cloud First” policy introduced in 2010; cloud migration continues to be a priority.
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The old business adage runs, “Nothing happens until somebody sells something.” To which you might add this corollary: nothing good happens in the absence of strong requirements.
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DLT Solutions recently sat down with NetApp Senior Director of U.S. Public Sector Channel Sales, David Drahozal, to discuss the recent revolution of NetApp's data fabric solutions.
DLT: So David, tell us a little about what you do at NetApp.
David: For over a decade, I’ve had the privilege of leading the US Public Sector channel here at NetApp. Its been a real exciting time as we have evolved from a NAS company to a leader in the consolidated virtualized data center, to today being a leader in hybrid cloud capabilities.
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The latest data on the progress of federal government agencies’ implementation of the Federal Information Technology Acquisition Reform Act (FITARA) was released on June 26 by the House Oversight and Reform Committee as Scorecard 8.0.
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Key takeaways show how public sector customers are achieving more with cloud.
As cloud continues to transform the public sector, cloud has had its own metamorphosis: from a trendy buzz word to a catalyst for meaningful change, innovation, and more. Last month, AWS hosted its 10th annual AWS Public Sector Summit. The conference brought together more than 17,000 attendees for 2+ days of insights, sessions, and networking, and explored how cloud is fueling the public sector for a limitless future.
Recap
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Uncategorized
Many states' fiscal years are quickly coming to an end, and at DLT we’re committed to making the job of the procurement officer as easy as possible as they scramble to make smart and responsible purchasing decisions with remaining taxpayer dollars. Part of this process is raising awareness of what’s new in our extensive portfolio of IT solutions including big data and analysis, cloud, cybersecurity, application lifecycle, digital design, IT consolidation and management, and more.
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Earlier this year DLT announced they were selected as the “Master Government Aggregator”
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It’s that time of year again! Spring is here and Autodesk has commenced its steady roll-out of 2020 software releases.
First off is AutoCAD 2020. Released in late March 2019, AutoCAD 2020 includes interesting and exciting new features. With a subscription to AutoCAD 2020, you’ll get industry-specific toolsets; improved workflows across all your devices – web, mobile, and desktop; and new integrations with cloud storage vendors.
Here’s a round-up of what’s new.
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Digital Design, Uncategorized
When we launched GovDesignHub in the spring of 2018, we had one goal in mind – to address the lack of resources, discussion, and analysis available online for those who practice in government digital design ecosystem.
Today, we’re proud to be the only website that showcases government design projects and the technology used to support them and deliver content to help public sector organizations accomplish their missions.
In the words of one of our top contributors, Lynn Allen, of Autodesk fame:
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Federal Fiscal Year End, Uncategorized
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Data & Storage
So much data, so little time. Disparate sources such as sensors, machines, geo-location devices, social feeds, server and security system logs, and more, are generating terabytes of data at unfathomable speeds. Getting any kind of real-time insight and, we dare you to dream, acting on that data as it flows in, is not an easy feat for resource-constrained government agencies.
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New York City Department of Design and Construction (NYC DDC) handles some of the most exciting and dynamic architectural and infrastructure challenges in the world.
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Digital Design, IT Perspective, News, Technology, Tips and How-Tos, Uncategorized
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Big Data, Big Data & Analytics, Data & Storage, Data and Analytics, Healthcare, Technology
Blockchain is no longer just a buzzword or simply a “technology to watch.” This database technology is being explored by agencies across government, from the General Services Administration (GSA) to Centers for Medicare and Medicaid Services (CMS), from the Federal Maritime Commission to military supply chain professionals across the Department of Defense (DoD).
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CAD General, Digital Design, IT Perspective, Technology, Uncategorized
Aside from developing one of the sought after building information modeling (BIM) software in the industry today, you’ve got to hand it to the Revit product managers over at Autodesk—they listen.
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CAD General, Digital Design, Technology, Uncategorized
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Cloud Computing, Cybersecurity, Data & Storage, IT Perspective, News, Technology, Uncategorized
Another day, another government ransomware victim. On March 22nd, 2018, the city of Atlanta found itself locked out of computers across government offices and facing a ransom demand of $51,000 or $6,800 per computer, GCN reported.
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Digital Design, Technology, Tips and How-Tos, Uncategorized
If you’re fairly new to Autodesk Revit and looking for ways to quickly get up to speed, Autodesk put together a great webinar that offers tips and tricks to get the most out of your user experience. Topics included:
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• What do I need to know to get started?
• What are some best practices for working in Revit?
• What are families and how do I use them?
• Where to learn more and how to get support when problems happen
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Cybersecurity, Infrastructure, Technology, Uncategorized
Microsoft Active Directory is a critical tool that helps system administrators manage user privileges and secure their IT infrastructure, yet Active Directory presents several security challenges. Most problematic is that Active Directory’s attack surface is huge. Targets for attack include every domain name user account, admin and security group, domain controller, backup, admin workstation, and admin delegations and privileges. If any one of these targets is compromised, your entire Active Directory can be compromised too.
The Threats
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Microsoft Active Directory is a critical tool that helps system administrators manage user privileges and secure their IT infrastructure, yet Active Directory presents several security challenges. Most problematic is that Active Directory’s attack surface is huge. Targets for attack include every domain name user account, admin and security group, domain controller, backup, admin workstation, and admin delegations and privileges. If any one of these targets is compromised, your entire Active Directory can be compromised too.
The Threats
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Are you thinking of moving your databases to the cloud? Perhaps, you’re thinking about transitioning to database-as-a-service (DBaaS)? But what’s involved? What hurdles must be overcome and how do you chart a path to cloud migration of your most sensitive workloads?
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Data & Storage
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News, Uncategorized
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News, Uncategorized
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News, Uncategorized
DNC Creates Cybersecurity Advisory Board Following Hack
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News, Uncategorized
The Most Critical Skills Gap: Cybersecurity
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News, Uncategorized
Technology Is Monitoring the Urban Landscape
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Social media has had a significant impact on federal, state, and local governments across the country. From the routine to the critical, social media has become a vital tool for building awareness of missions, sharing policy updates, communicating services and products, and enhancing citizen engagement. The immediacy of social media is also particularly useful to emergency response agencies who can leverage its outreach capabilities to aid response efforts.
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News, Uncategorized
Posing as Ransomware, Windows Malware Just Deletes Victims’ Files
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Uncategorized
It's finally here!
Amazon Web Services (AWS) just announced that the Elastic File System (or "EFS") is a live production service. The service is provisioned out of three regions currently: US-EAST-1, US-WEST-2, and EU-WEST-1.
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Reality capture technology as a means of capturing existing as-built conditions has been around for some time. Terrestrial laser scanning or LiDAR is just one example of reality capture (or recap) at work. But recap hasn’t always been easy. Scanning techniques are often expensive and the task of incorporating and manipulating large data sets (point clouds) during the design process is tricky.
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This All-Star Team Plans to Jumpstart 100 Cybersecurity Companies in 3 Years
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Data & Storage
Data is an incredibly important asset. Unfortunately, too many agencies continue to treat data as an easily replaced commodity.
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Marketing
News, Uncategorized
Why Small Bites Make Sense for Cloud
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Cybersecurity, Uncategorized
Data leaks, data breaches, blah, blah, blah. Sometimes the attention-grabbing headlines just sound like too much noise.
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IT Perspective, Uncategorized
When news broke last month that the Pentagon is still using 1970s-era floppy disks to run its nuclear program, most of us expressed incredulity. Unless you happen to work for the federal government that is.
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Data & Storage, Uncategorized
Growing data volumes and burgeoning virtual workloads are putting increasing pressure on public sector data center power and storage systems, while also taking a toll on staff and tax payer dollars.
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Data & Storage, Uncategorized
Growing data volumes and burgeoning virtual workloads are putting increasing pressure on public sector data center power and storage systems, while also taking a toll on staff and tax payer dollars.
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Data & Storage, Uncategorized
Data backup is a fundamental part of good IT and business management. But in the public sector it’s also the law. Established by President Obama in 2011, the National Archives and Records Administration maintains a comprehensive backup of all records of important transactions, actions, and other communications.
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Caron Beesley
Data & Storage, Uncategorized
Data backup is a fundamental part of good IT and business management. But in the public sector it’s also the law. Established by President Obama in 2011, the National Archives and Records Administration maintains a comprehensive backup of all records of important transactions, actions, and other communications.
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Caron Beesley