EMC D-XTR-DS-A-24 - Dell XtremIO Design Achievement

For ESXi disks provisioned by XtremIO, the recommended disk format is ‘Eager Zeroed Thick’. This format is preferred because it allocates all the space required for the disk at the time of creation and zeroes out any previous data on the physical media. Compared to other formats, ‘Eager Zeroed Thick’ provides better performance due to the pre-zeroing of the disk space, which helps in avoiding any latency that might occur during write operations as there is no need to zero out blocks before writing new data.

References:

While the specific Dell XtremIO Design document was not available, the general best practice for high-performance storage solutions like XtremIO is to use ‘Eager Zeroed Thick’ provisioning for VMs running on VMware ESXi to ensure optimal performance1.

Additional information on disk provisioning and best practices can be found in VMware’s official documentation and Dell EMC’s storage configuration guides2.

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XtremIO XVC (XtremIO Virtual Copies) allows for efficient snapshot management and operations, including the refresh of volumes. One of the key features of XVC is that it enables the refresh of a production volume from a snapshot without requiring the volume to be unmounted from the host. This capability is designed to minimize disruption and maintain continuous availability of data to applications during refresh operations.The refresh operation is handled within the XtremIO storage array, and the production volume remains accessible to the host during this process1.

References:

The Dell XtremIO Design Achievement document provides information on the capabilities and features of XtremIO X2 systems, including XVC operations1.

Additional details on XVC refresh operations can be found in the support documentation for the XtremIO Family on Dell’s official website2.

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An XtremIO cluster’s ability to support snapshots and volumes scales with the number of X-Bricks in the cluster.According to the documentation, an XtremIO X2 cluster can support up to 32K objects (root volumes + snapshots) per cluster1. Therefore, with the expansion from two to four X2 X-Bricks, the cluster would be able to support up to 32,768 snapshots and volumes.

References:

The Dell EMC XtremIO X2: Next-Generation All-Flash Array document states the infrastructural scale supporting up to 32K objects per cluster1.

Additional information on the scalability and performance of XtremIO X2 clusters can be found in the Introduction to XtremIO X2 Storage Array document2.

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When configuring the iSCSI SAN from the host to the XtremIO cluster, it is recommended to disable flow control features on the server, switches, and array ports.Flow control can cause a performance impact by serializing the flow for iSCSI ports, which is not desirable in high-performance storage solutions like XtremIO1. Disabling flow control ensures that the storage array operates without the limitations that flow control can impose, thus maintaining optimal performance.

References:

Dell EMC Switch Configuration Guide for iSCSI and Software-Defined Storage provides guidelines for the design and configuration of storage networks for iSCSI SAN, which includes recommendations on flow control settings2.

Community discussions on Dell Technologies website where it is mentioned that the latest best practices advise against enabling flow control for iSCSI with XtremIO, as it limits performance1.

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A response code of 400 in the context of RESTful API operations generally indicates that the request made by the client was malformed or contains a syntax error. This means that the data stream sent by the client to the server did not follow the rules as defined by the API specification.It could be due to various reasons such as incorrect request format, missing required parameters, or invalid parameter values1.

In the case of the Dell XtremIO environment, if a customer receives a 400 response code when attempting to create a volume via the RESTful API, it is likely due to a syntax error in the API command.The customer should review the API request to ensure that it conforms to the expected format and includes all necessary information as per the XtremIO API documentation2.

References:

Community discussions on the Dell Technologies website where similar issues have been addressed and the cause of the 400 error was identified as a syntax error in the RESTful API command2.

General information about the meaning of a 400 Bad Request error in REST APIs, which supports the conclusion that a syntax error is the cause1.

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The XMS Simulator is a standalone tool designed to demonstrate the various management capabilities of XtremIO. It allows users to interact with a simulated XtremIO environment, providing a safe space to learn and understand the management operations without affecting actual data or systems.The simulator includes features that replicate the actual XtremIO Management Server (XMS), making it an ideal tool for training, demonstrations, and gaining familiarity with XtremIO’s management features1.

References:

The Dell XtremIO Design Achievement document outlines the critical components and best practices for designing solutions with XtremIO, which includes the use of tools like the XMS Simulator for demonstration purposes1.

Additional resources and documentation on the XtremIO Family support page may provide further insights into the use of the XMS Simulator2.

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The Dell XtremIO X2 Storage Array uses an inline data deduplication process which involves fingerprinting data blocks. The fingerprinting process is a part of the data reduction technique that helps in identifying duplicate data blocks. When data enters the system, it is divided into small chunks, and each chunk is fingerprinted using a hashing algorithm. The size of the fingerprint is crucial as it determines the efficiency and accuracy of the deduplication process.

The specific bit size of the fingerprint created by the algorithm used by XtremIO is256 bits.This information is derived from the detailed descriptions of the system’s architecture and operation as provided in the Dell EMC XtremIO X2 Storage Array documentation1. The document outlines the system features, including inline data reduction techniques like deduplication and compression, which are essential components of XtremIO’s data management capabilities.

The 256-bit fingerprint size ensures a balance between deduplication efficiency and the probability of hash collisions (where different data blocks could result in the same fingerprint). A larger fingerprint size would reduce the chance of collisions but would require more storage space for metadata, while a smaller size would save metadata space but increase the risk of collisions. Therefore, the 256-bit size is a strategic choice for the XtremIO system’s deduplication process.

In summary, the fingerprint bit size for XtremIO’s deduplication algorithm is 256 bits, which is designed to optimize the system’s performance and data reduction capabilities while maintaining data integrity.

The Oracle Redo Log block size is recommended to be set to 8 kB.This is based on the best practices for Oracle 19c Database, where it was found that increasing the size of the Oracle redo logs can improve database performance12. However, it’s important to note that not every workload will show significant performance increase when increasing the size of the redo logs. Customers should evaluate the AWR to determine if the redo logs have an associated high number and duration of wait times.If the redo logs show a possible bottleneck, then increasing the size of the redo logs could improve performance2.