Archive for the ‘Product Tips’ Category

The top 3 operational differences between EMC Isilon OneFS 6.5 and OneFS 7.0

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

isilon-onefs-7-0Attention all current EMC® Isilon® OneFS 6.5 users: OneFS 6.5 will reach its end of service life (EOSL) on June 30, 2015. OneFS 7.0 introduces several new features, enhancements, and operational changes. If you need to upgrade to OneFS 7.0, you might be wondering what’s different about this version and how these differences will affect your day-to-day administrative tasks. You can learn more by looking at the Administrative Differences in OneFS 7.0 white paper.

The top three changes that OneFS 6.5 users should prepare for are:

  • Administration using role-based access control (RBAC)
  • Authentication using access zones
  • Managing groups of nodes in SmartPools

Role-based access control

In OneFS 6.5, you can grant web and SSH login and configuration access to non-root users by adding them to the admin group. The admin group is replaced with the administrator role in OneFS 7.0 using RBAC. A role is a collection of OneFS privileges, usually associated with a configuration subsystem, that are granted to members of that role as they log in to the cluster.

For information about role-based access, including a description of roles and privileges, see Isilon OneFS 7.0: Role-Based Access Control.

An important note!

After you upgrade to OneFS 7.0, make sure you add existing administrators to an administrator role.

Access Zones

In OneFS 7.0, all user access to the cluster is controlled through access zones. With access zones, you can partition the cluster configuration into self-contained units and configure a subset of parameters as a virtual cluster with its own set of authentication providers, user mapping rules, and SMB shares. The built-in access zone is the “System” zone, which by default provides the same behavior as OneFS 6.5, using all available authentication providers, NFS exports, and SMB shares.

For information about access zones, see the OneFS 7.0.2 Administration Guide.

SmartPools

In OneFS 6.5, a group of nodes is called a disk pool. In OneFS 7.0, a group of nodes is called a node pool, and a group of disks in a node pool is called a disk pool. Also, Isilon nodes are automatically assigned to node pools in the cluster based on the node type. This is called autoprovisioning. Disk pools can no longer be viewed or targeted directly through the OneFS 7.0 web administration interface or the command-line interface. Instead, the smallest unit of storage that can be administered in OneFS 7.0 is a node pool. Disk pools are managed exclusively by the system through autoprovisioning.

An important note!

Before you upgrade to OneFS 7.0, you must configure disk pools into a supported node pool configuration. Disk pools must contain nodes of the same type, according to their node equivalence class. Disk pools that contain a mixture of node types must be reconfigured.

For information about how to prepare your Isilon cluster for upgrade to OneFS 7.0, see the Isilon OneFS 7.0.1 – 7.0.2 Upgrade Readiness Checklist.

For more information about OneFS 7.0

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Start a conversation about Isilon content

Have a question or feedback about Isilon content? Visit the online EMC Isilon Community to start a discussion. If you have questions or feedback about this blog, contact us at isi.knowledge@emc.com. To provide documentation feedback or request new content, contact isicontent@emc.com.

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How EMC Isilon InsightIQ helps keep your cluster running smoothly

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

We highlighted a crucial cluster maintenance task in a recent blog post: monitoring cluster performance and storage capacity. Now, we’d like to take a closer look at InsightIQ™—a remarkably useful tool for monitoring your EMC® Isilon® cluster. As a licensed software module for the OneFS® operating system, InsightIQ makes it possible for you to monitor one or more clusters.

InsightIQ provides charts, graphs, and customized reports to help you understand how your cluster is performing. To learn how InsightIQ 3.0 works, watch the EMC Isilon InsightIQ Overview video, where Corporate Systems Engineer Jason Sturgeon describes the architecture of InsightIQ and shows you how to use InsightIQ reports.

How reports can help with monitoring

InsightIQ enables you to create customized reports to display data about clusters over specific periods of time. There are two general types of reports: performance reports and file system reports.

Performance reports

By monitoring cluster performance and data usage, you can help to ensure that your cluster runs smoothly. In the InsightIQ overview video, learn how to create a performance report to check cluster activity and a file system report to visualize data usage over time.

For example, if your cluster is running slowly, you can run a performance report and review the external network throughput rate. In the following figure, the performance report shows that one node is handling more network traffic than other nodes. With this information, you can redirect network traffic to other nodes and improve cluster performance.

A performance report that shows which node is handling the majority of network traffic.

A performance report in InsightIQ 3.0 that shows which node is handling the majority of network traffic.

 

 

 

 

 

 

 

 

 

File system report

InsightIQ reports can also help you to monitor cluster data usage by generating a file system report. The video describes a use case where you can explore data growth in a directory over time. For example, after running a file system report you might notice that a directory is storing a large amount of data (see the following figure). If this data hasn’t been accessed for a long time, you can approach the directory owner to determine whether this data can be deleted to increase storage capacity.

A file system report that shows a directory storing a large amount of data.

A file system report in InsightIQ 3.0 that shows a directory storing a large amount of data.

 

 

 

 

 

 

 

For more information about reporting capabilities in InsightIQ, refer to the InsightIQ documentation on the EMC Online Support site (login required).

Start a conversation about Isilon content

Have a question or feedback about Isilon content? Visit the online EMC Isilon Community to start a discussion. If you have questions or feedback about this blog, contact us at isi.knowledge@emc.com. To provide documentation feedback or request new content, contact isicontent@emc.com.

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Five preventative maintenance tasks for your EMC Isilon cluster

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

131704545The last thing you want is for your cluster to go down because of an issue that could have been avoided. Performing routine cluster maintenance is important for keeping your EMC® Isilon® cluster up-and-running.

Five simple cluster maintenance tasks are highlighted in the new video, “How to Keep Your EMC Isilon Cluster Running Smoothly.” You can also find these tasks and more in the Isilon Cluster Preventative Maintenance Checklist (login to the EMC Online Support site is required).

Here’s a summary of the five tasks covered in the video:

  1. Subscribe to Isilon product advisories and updates in the EMC Online Support site. After you subscribe, regular Isilon documentation updates, EMC Technical Advisories, and more will be delivered directly to your email inbox.
  2. Check your cluster’s physical environment. Check the temperature, humidity, and power distribution unit (PDU) of your data center on a regular basis. You can also consult the Isilon Site Preparation and Planning Guide for environmental thresholds and requirements to protect your hardware from physical damage.
  3. Review the status of data protection jobs each month. Whether you’re using Isilon SnapshotIQ™, SyncIQ™, or NDMP for data replication or backups, it’s important to check the reports in the OneFS web administration interface or the log files of these tools to make sure your data is constantly protected. By routinely checking for any failed jobs, you have time to address them before you find yourself in a scenario where you need to recover data.
  4. Monitor cluster capacity daily. One of the most important things you can do to ensure that your cluster runs smoothly is to prevent it from reaching capacity. There are several best practices you can follow to maintain enough free space, which are summarized in an ISI Knowledge blog post, and the file system section of the Isilon Cluster Preventative Maintenance Checklist. The video below demonstrates how to monitor cluster usage by either checking the dashboard in the OneFS web administration interface or running performance reports using Isilon InsightIQ™.
  5. Check for cluster software and firmware every six months. Specifically, look for and install maintenance releases (MRs) and firmware updates when they become available. You’ll be notified of new MRs and firmware updates through Isilon product updates that you subscribed to in step one. You can also check the Current Isilon Software Releases document for a list of latest and recommended updates.

Start a conversation about Isilon content

Have a question or feedback about Isilon content? Visit the online EMC Isilon Community to start a discussion. If you have questions or feedback about this blog, send an email to isi.knowledge@emc.com. To provide documentation feedback or request new content, send an email to isicontent@emc.com.

 

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Is your site ready for an EMC Isilon cluster?

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

If you’re in the market for a new data storage solution, such as an EMC® Isilon® scale-out network attached storage (NAS) system, you’ve probably done a good amount of research to determine which solution will best meet your needs.

One important area of research is determining if your data center is ready for an EMC Isilon cluster. The Isilon Site Preparation and Planning Guide (login with an EMC Community Network account required) can help answer important questions about how to prepare a data center infrastructure for new Isilon equipment. Designed for system administrators or facility managers, this guide offers specific information about environmental and power requirements for data centers.

The information in this guide extends beyond providing site requirements. It’s also a useful reference for selecting equipment and preparing for the arrival and set up of your new cluster.

Selecting the right equipment

EMC Isilon NodesThe Isilon Site Preparation and Planning Guide is a singular resource for specifications and recommendations about all the equipment that makes up an Isilon cluster.

For example, this guide includes specifications for the following:

  • Nodes: Get specs on storage capacity, dimensions, and more for all supported nodes including S210, S200, X200, X410, X400, NL400, and A100 accelerator nodes.
  • Rack cabinets: Learn about standard storage racks requirements and delivery dimensions.
  • Cables: Get recommendations for managing InfiniBand and Cat 5 cables. For demonstrations of proper cable management, watch the EMC Isilon Site Preparation and Planning: Cabling video.

Installing your cluster

For an overview of cluster installation basics, such as topology, node positioning, and planning for expansion or service needs, watch the EMC Isilon Site Preparation and Planning: Cluster Installation video.

To help you with the installation process, Isilon Professional Services can assist you with setting up your new Isilon cluster to meet the needs of your specific workflows. The Isilon Site Preparation and Planning Guide provides a list of what to consider when first installing your cluster, which you can review with your Professional Services account representative:

  • Which version of the Isilon OneFS® operating system to install on the cluster
  • Network connectivity details, including IP ranges, for your cluster nodes, client, and InfiniBand networks
  • DNS configuration details, including name servers and search lists
  • Directory services such as Active Directory, LDAP, NIS, or local user groups
  • File sharing protocols such as SMB and NFS, and advanced file sharing options
  • Data protection levels, anti-virus solutions, NDMP backup, and auditing
  • Cluster alert solutions such as ESRS and SNMP monitoring

For more complete information on these topics, read the Isilon Site Preparation and Planning Guide.

Start a conversation about Isilon content

Have a question or feedback about Isilon content? Visit the online EMC Isilon Community to start a discussion. If you have questions or feedback about this blog, send an email to isi.knowledge@emc.com. To provide documentation feedback or request new content, send an email to isicontent@emc.com.

 

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Understanding Global Namespace Acceleration (GNA)

Colin Torretta

Colin Torretta

Senior Technical Writer
Colin Torretta

Latest posts by Colin Torretta (see all)

With the proliferation of solid state drives (SSDs) in data centers across the world, companies are finding more and more ways to take advantage of the high speed and low latency of SSDs in unique and exciting ways. Within the EMC® Isilon® OneFS® operating system, one of the innovative ways Isilon is using SSDs is for Global Namespace Acceleration (GNA). GNA is a feature of OneFS that increases performance across your entire cluster by using SSDs to store file metadata for read-only purposes, even in node pools that don’t contain dedicated SSDs.

GNA is managed through the SmartPools™ software module of the OneFS web administration interface. SmartPools enables storage tiering and the ability to aggregate different type of drives (such as SSDs and HDDs) into node pools. When GNA is enabled, all SSDs in the cluster are used to accelerate metadata reads across the entire cluster. Isilon recommends one SSD per node as a best practice, with two SSDs per node being preferred. However, customers with a mix of drive types can benefit from the metadata read acceleration with GNA regardless of how SSDs are placed across the cluster. When possible, GNA stores metadata in the same node pool containing the associated data. If there are no dedicated SSDs in the node pool, however, a random selection is made to any node pool containing SSDs. This means as long as SSDs are available somewhere in the cluster, a node pool can benefit from GNA.

For more information about GNA, see the “Storage Pools” section of the OneFS web administration and CLI administration guides.

Important considerations when using GNA

Here are some important considerations to keep in mind when determining whether GNA can benefit your workflow.

  • Use GNA for cold data workflows. Certain workflows benefit more from the performance gains that GNA provides. For example, workflows that require heavy indexing of “cold data”—which is archive data on stored on disks that is left unmodified for extended periods of time—benefit the most from the increased speed of metadata read acceleration. GNA does not provide any additional benefit to customers who already have solely SSD clusters, because all metadata is already stored on SSDs.
  • SSDs must account for a minimum of 1.5% of the total space on your cluster. To use GNA, 20% of the nodes in your cluster must contain SSDs, and SSDs must account for a minimum of 1.5% of the total space on your cluster, with 2% being strongly recommended. This ensures that GNA does not overwhelm the SSDs on your cluster. Failure to maintain these requirements will result in GNA being disabled and metadata read acceleration being lost. To enable GNA again, metadata copies will have to be rebuilt, which can take time.
  • Consider how new nodes affect the total cluster space. Adding new nodes to your cluster affects the percentage of nodes with SSDs and total available space on SSDs. Keep this in mind whenever you add new nodes to avoid GNA being disabled and the metadata copy being immediately deleted. SSDs must account for a minimum of 1.5% of total space on your cluster.
  • Do not remove the extra metadata mirror. When GNA is enabled, an SSD is set aside as an additional metadata mirror, in addition to the existing mirrors set by your requested protection, which is determined in SmartPools settings. A common misunderstanding is that the SSD is an “extra” mirror and it can be safely removed without affecting your cluster. In reality, this extra metadata mirror is critical to the functionality of GNA, and removing it causes OneFS to rebuild the mirror on another drive. See the graphic below for information on the number of metadata mirrors per requested protection when using GNA. For more information about requested protection, see the “Storage Pools” section of the OneFS Web Administration Guide.
The number of metadata mirrors required by GNA per requested protection level in OneFS.

The number of metadata copies required by GNA to achieve read acceleration per requested protection level in OneFS.

 

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Creating SMB shares with expansion variables in EMC Isilon OneFS

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

To make it easy for users in your organization to connect to a home directory through a Windows client, you can create an SMB share in EMC® Isilon® OneFS®. The share specifies configurable permissions, performance, and security settings for each individual user. Managing SMB shares in OneFS 6.5 through 7.1 can be done manually for each user, or dynamically for a large number of users. To create an SMB share or home directory, you can take advantage of these approaches:

  • Create unique SMB shares for user home directories
    • Dynamically create a unique share for each user home directory
    • Manually create a unique share for each user home directory
  • Create a common SMB share for user home directories
    • Dynamically create user home directories in a common share
    • Manually create user home directories in a common share

Each one of these approaches is highlighted in the new white paper, “Managing SMB shares and user home directories in OneFS 6.5 and later.”

How to dynamically create an SMB share using expansion variables

One of the approaches, as described in “Managing SMB shares and user home directories in OneFS 6.5 and later,” is to dynamically create SMB shares and home directories for new users. Instead of creating per-user SMB shares, you can create a single share that includes expansion variables, such as %U for the user name. For example, when a new user logs in through Active Directory, OneFS automatically creates a unique SMB share and directory for that user.

To dynamically create unique SMB shares using name expansion variables, follow these steps:

In OneFS 7.0 and OneFS 7.1

To take full advantage of expansion variables in SMB shares, you should be running OneFS 7.0.2.9 and later, or OneFS 7.1.0.2 and later.

  1. Log in to the OneFS web administration interface.
  2. Click Protocols > Windows Sharing (SMB) > SMB Shares > Add a Share.
  3. Type a share name (for example, Home) and optional description (for example, User Home Directories).
  4. In the Directory to Be Shared box, type /ifs/home/%U. If you store home directories in another location, specify that location instead.
  5. Click Apply Windows Default ACLs.
  6. Select the Allow Variable Expansion check box.
  7. Select the Auto-Create Directories check box.
  8. Click Create.

Dynamically create SMB share and home directories using expansion variables.

In OneFS 6.5

  1. Log in to the OneFS web administration interface.
  2. Click File Sharing > SMB > Add Share.
  3. Type a share name (for example, Home) and description (for example, User Home Directories).
  4. In the Directory to share box, type /ifs/home/%U. If you store home directories in another location, specify that location instead.
  5. Click Apply Windows default ACLs.
  6. Select the Allow Username Expansion check box.
  7. Selectthe Automatically Create User Directory check box.
  8. Click Submit.

More information about SMB and home directories in OneFS

For more information about expansion variables, see the “Create an SMB share” and “Home directory creation in a mixed environment” sections in the OneFS web administration guides. The administration guide also provides configuration information for accessing home directories through FTP or SSH.

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Learn about advanced troubleshooting techniques for EMC Isilon clusters at EMC World 2014

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

technical difficultiesWhen you experience technical difficulties with your EMC® Isilon® cluster, you want to quickly find the source of the issue and resolve it. Some issues, such as data integrity errors, require immediate attention from EMC Isilon Technical Support. However, there are issues that you can effectively troubleshoot yourself.

Learn the techniques to become more effective at troubleshooting. Tim Wright, Technical Support Engineer, will cover specific troubleshooting scenarios and tools during the EMC World 2014 session, “Advanced Troubleshooting of EMC Isilon Clusters.” If you’re attending EMC World 2014 in Las Vegas, Nevada, you can attend his sessions on the following dates:

  • May 5, 3:00 PM – 4:00 PM
  • May 8, 10:00 AM – 11:00 AM

Tim’s session will cover:

For more information about session date, times, and locations, visit the Session Catalog on the EMC World 2014 website.If you are unable to attend EMC World 2014, let us know which troubleshooting issues you would like to learn more on this blog by sending an email to isi-knowledge@emc.com.

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7 best practices for setting up Hadoop on an EMC Isilon cluster

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

If you’re considering adding an Apache™ Hadoop® workflow to your EMC® Isilon® cluster, you’re probably wondering how to set it up. The new white paper “EMC Isilon Best Practices for Hadoop Data Storage” provides useful information for deploying Hadoop in your Isilon cluster environment.

The white paper also introduces the unique approach that Isilon took to Hadoop deployments. In a typical Hadoop deployment, large unstructured data sets are ingested from storage repositories to a Hadoop cluster based on the Hadoop distributed file system (HDFS). Data is mapped to the Hadoop DataNodes of the cluster and a single NameNode controls the metadata. The MapReduce software framework manages jobs for data analysis. MapReduce and HDFS use the same hardware resources for both data analysis and storage. Analysis results are then stored in HDFS or exported to other infrastructures.

Traditionl Hadoop Deployment

In an EMC Isilon Hadoop deployment, the HDFS is integrated as a protocol into the Isilon distributed OneFS® operating system. This approach gives users direct access through the HDFS to data stored on the Isilon cluster using standard protocols such as SMB, NFS, HTTP, and FTP. MapReduce processing and data storage are separated, allowing you to independently scale compute and data storage resources as needed.

EMC Isilon Hadoop Deployment

Every node in the Isilon cluster acts as the NameNode and DataNode. Compute clients running MapReduce jobs can connect to any node in the cluster. Data analysis results can be accessed by Hadoop users through standard protocols without the need to export results.

To learn more about the benefits of Hadoop on Isilon scale-out network attached storage (NAS), read “Hadoop on EMC Isilon Scale-Out NAS” and “EMC Isilon Scale-Out NAS for In-Place Hadoop Data Analytics.”

Best practices for deploying Hadoop to your Isilon cluster

You can connect Apache Hadoop or an enterprise-friendly Hadoop distribution, such as Pivotal HD or Cloudera, to your Isilon cluster.

First, you’ll need to turn on the HDFS protocol in OneFS. Contact your account representative to complete this step. Next, follow these best practices:

  1. Review the EMC Hadoop Start Kit 2.0. Visit the EMC Hadoop Starter Kit (HSK) 2.0 for step-by-step guides on how to connect a Hadoop distribution to your Isilon cluster. HSK guides are available for Apache Hadoop, Pivotal HD, Cloudera, and Hortonworks. A video demonstration for Pivotal HD is also available.
  2. Find your Isilon cluster’s optimal point to help determine the number of nodes that will best serve your Hadoop workflow and compute grid. The optimal point is the point at which it scales in processing MapReduce jobs and reduces run times in relation to other systems for the same workload. Contact your account representative to help you determine this information.
  3. Create directories and set permissions. OneFS controls access to directories and files with POSIX mode bits and access control lists (ACLs). Make sure directories and files are set up with the correct permissions to ensure that your Hadoop users can access their files.
  4. Don’t run NameNode and DataNode services on clients. Because the Isilon cluster acts as the NameNode and DataNodes for the HDFS, these services should only run on the cluster and not on compute clients. On compute clients, you should only run MapReduce processes.
  5. Increase the HDFS block size from the default 64 MB to 128 MB to optimize performance. Boosting the block size lets Isilon nodes read and write HDFS data in larger blocks. The result is an increase in performance of MapReduce jobs.
  6. Store intermediate jobs on an Isilon cluster. A Hadoop client typically stores its intermediate map results locally. The amount of local storage available on a client affects its ability to run jobs. Storing map results on the cluster can help performance and scalability.
  7. Consult the Isilon best practices white paper for additional tips. You can find more details about some of these best practices in “EMC Isilon Best Practices for Hadoop Data Storage.” You can also find additional tips for tuning OneFS for HDFS operations, using EMC Isilon SmartConnect™ for HDFS, aligning datasets with storage pools, and securing HDFS connections with Kerberos.

 

If you have questions related to Hadoop and your Isilon environment, contact your account representative. If you have documentation feedback or want to request new content, email isicontent@emc.com.

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How to keep your EMC Isilon cluster from reaching capacity

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

It’s important to maintain enough free space on your EMC® Isilon® cluster to ensure that data is protected and workflows are not disrupted. At a minimum, you should have at least one node’s worth of free space available in case you need to protect data on a failing drive.

When your Isilon cluster fills up to more than 90% capacity, cluster performance is affected. Several issues can occur when your cluster fills up to 98% capacity, such as substantially slower performance, failed file operations, the inability to write or delete data, and the potential for data loss. It might take several days to resolve these issues. If you have a full cluster, nearly full cluster, or need assistance with maintaining enough free space, contact EMC Isilon Technical Support.

Fortunately, there are several best practices you can follow to help prevent your Isilon cluster from becoming too full. These are detailed in the “Best Practices Guide for Maintaining Enough Free Space on Isilon Clusters and Pools” (requires login to the EMC Online Support site). Some of these best practices are summarized in this blog post.

Monitoring cluster capacity

To prevent your cluster from becoming too full, monitor your cluster capacity. There are several ways to do this. For example, you can configure email event notification rules in the EMC Isilon OneFS® operating system to notify you when your cluster is reaching capacity. Watch the video “How to Set Up Email Notifications in OneFS When a Cluster Reaches Capacity” for a demonstration of this procedure.

Another way to monitor cluster capacity is to use EMC Isilon InsightIQ™ software. If you have InsightIQ licensed on your cluster, you can run FSAnalyze jobs in OneFS to create data for InsightIQ’s file system analytics tools. You can then use InsightIQ’s Dashboard and Performance Reporting to monitor cluster capacity. For example, Performance Reports enable you to view information about the activity of the nodes, networks, clients, disks, and more. The Storage Capacity section of a performance report displays the used and total storage capacity for the monitored cluster over time (Figure 1).

Figure 1: The Storage Capacity section of a Performance Report in InsightIQ 3.0.

Figure 1: The Storage Capacity section of a Performance Report in InsightIQ 3.0.

For more information about InsightIQ Performance Reports, see the InsightIQ User Guides, which can be found on the EMC Online Support site.

To learn about additional ways to monitor cluster capacity, such as using SmartQuotas, read “Best Practices Guide for Maintaining Enough Free Space on Isilon Clusters and Pools.”

More best practices

Follow these additional tips to maintain enough free space on your cluster:

  • Manage your data
    Regularly delete data that is rarely accessed or used.
  • Manage Snapshots
    Snapshots, which are used for data protection in OneFS, can take up space if they are no longer needed. Read the best practices guide for several best practices about managing snapshots, or read the blog post “EMC Isilon SnapshotIQ: An overview and best practices.”
  • Make sure all nodes in a node pool or disk pool are compatible
    If you have a node pool that contains a mix of different node capacities, you can receive “cluster full” errors even if only the smallest node in your node pool reaches capacity. To avoid this scenario, ensure that nodes in each node pool or disk pool are of compatible types. Read the best practices guide for information about node compatibility and for a procedure to verify that all nodes in each node pool are compatible.
  • Enable Virtual Hot Spare
    Virtual Hot Spare (VHS) keeps space in reserve in case you need to move data off of a failing drive (smartfail). VHS is enabled by default. For more information about VHS, read the knowledgebase article, “OneFS: How to enable and configure Virtual Hot Spare (VHS) (88964)” (requires login to the EMC Online Support site).
  • Enable Spillover
    Spillover allows data that is being sent to a full pool to be diverted to an alternate pool. If you have licensed EMC Isilon SmartPools™ software, you can designate a spillover location. For more information about SmartPools, read the OneFS Web Administration Guide.
  • Add nodes
    If you want to scale-out your storage to add more free space, contact your sales representative.

If you have questions or feedback about this blog or video described in it, send an email to isi.knowledge@emc.com. To provide documentation feedback or request new content, send an email to isicontent@emc.com.

 

EMC Isilon SnapshotIQ: An overview and best practices

Kirsten Gantenbein

Kirsten Gantenbein

Principal Content Strategist at EMC Isilon Storage Division
Kirsten Gantenbein
Kirsten Gantenbein

If you want to capture a moment in time with a camera, you snap a picture. When you want to capture the data on your cluster at a moment in time with the EMC® Isilon® OneFS® operating system, you take a snapshot.

EMC Isilon SnapshotIQ™ is a licensed software module that lets you create new snapshots and manage snapshot schedules. In this blog post, you’ll learn about SnapshotIQ basics and best practices.

SnapshotIQ overview

A snapshot is taken at a directory-level. The snapshot maintains an image of data that existed in that directory at that moment when the snapshot was created, even if the data changes. Taking a snapshot is an instantaneous operation. Rather than create a redundant copy of the data blocks, snapshots use pointers to reference current blocks on the cluster. Because of this, snapshots do not consume additional disk space unless the data referenced by the snapshot is modified. If the files are modified, the snapshot stores read-only copies of the original blocks.

Image provided by Patrick Kreuch

Image provided by Patrick Kreuch

Snapshots are the foundation for data protection strategies in OneFS. Snapshots are also used by the EMC Isilon SyncIQ™ software module to replicate a consistent point-in-time image of a directory from one cluster to another.

Watch the following video, “Data Protection and Disaster Recovery with Isilon SnapshotIQ,” to learn how to manage snapshots with the SnapshotIQ module. EMC Isilon Senior Solutions Architect, Chris Klosterman, answers the following frequently asked questions:

  • What is a snapshot and why do I need it?
  • How does SnapshotIQ work?
  • Where does OneFS store snapshots?
  • What are some example schedules?
  • How is data restored?
  • When do OneFS snapshots expire and how is the snapshot space reclaimed?
  • Can I modify data in a snapshot?

SnapshotIQ best practices

You may find that working with a large number of snapshots can become challenging to manage. Consider the following best practices to improve snapshot management and avoid cluster performance degradation.

  • Do not create more than 1,000 snapshots of a single directory.
  • Consider the depth of the directory path when creating snapshots. If the path is too high on the directory tree, it will cost more cluster resources to modify data referenced by the snapshot. If the path is too deep, you may need to create more snapshot schedules, which can be difficult to manage.
  • Create an alias name for your snapshot schedules in the OneFS web administration interface. Use the alias name to help you look up the most recent snapshot generated from a schedule.
  • Do not disable the snapshot delete job in the OneFS Job Engine.

For additional best practices and details about SnapshotIQ, see the “Snapshots” section in the OneFS Administration Guide.

If you have questions or feedback about this blog or these videos, email isi.knowledge@emc.com. To provide documentation feedback or request new content, email isicontent@emc.com.