Dell EqualLogic PS Series Storage Arrays iSCSI Initiator and Operating System Considerations Optimizing Your SAN Environment for High Availability
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Contents About This Manual.........................................................................................................................5 Audience...................................................................................................................................................................5 Related Documentation............................................................................................................................................ 5 Related Sites.............
B Configure Your VMware Environment...................................................................................18 Set iSCSI Login Timeout Value on vSphere 5.1 and 5.0...........................................................................................18 Storage Heartbeat on vSphere 5.0, 4.1, and 4.0......................................................................................................18 C Configure Your Linux Operating System......................................................
About This Manual Dell EqualLogic PS Series arrays optimize resources by automating performance and network load balancing. Additionally, PS Series arrays offer all-inclusive management firmware, host software, and free firmware updates. Dell EqualLogic FS Series appliances, combined with PS Series arrays, offer a high-performance, high-availability, scalable NAS solution.
Dell EqualLogic Storage Solutions To learn more about Dell EqualLogic products and new releases being planned, visit the Dell EqualLogic TechCenter site: Dell EqualLogic TechCenter. You can also see articles, demos, online discussions, and more details about the benefits of our product family. Technical Support and Customer Service Dell support service is available to answer your questions about PS Series SAN arrays and FS Series appliances.
About High-Availability iSCSI Data Transfer 1 When you optimize your SAN environment for high availability (HA), you increase the fault tolerance of the SAN. Fault tolerance provides protection from component failures and minimizes service disruptions. Many causes of service disruptions can occur in a data center.
Configure Your Hosts for High Availability 2 This section provides information about Host Integration Tools and operating system recommendations. Host Integration Tools Dell has automated a portion of the configuration process in the Dell EqualLogic Host Integration Tools kits. These kits provide integrated software such as MPIO modules, enhanced data protection, automated provisioning, and alerts for Windows, VMware, and Linux hosts.
Configure Your Network for High Availability 3 A Dell EqualLogic iSCSI SAN can be operated in any network that supports the industry standards and IP subnet design guidelines described in this section. Because of this flexibility, many network design and configuration choices can affect SAN performance. For additional network design and configuration information to support the use of a Dell EqualLogic SAN, see the PS Series Configuration Guide. This guide can be downloaded from: http://en.community.dell.
Figure 1. Redundant SAN PS4100 Figure 2. Redundant SAN PS6100 • Both link aggregation group (LAG) or stacking interconnects can be used as the bridging mechanism between redundant switches in the EqualLogic SAN, but each method has a different set of considerations that might make one approach more preferable than the other. For more information about LAG and stacking considerations, see the PS Series Configuration Guide at: http://en.community.dell.
http://en.community.dell.com/techcenter/storage/w/wiki/4250.switch-configuration-guides-by-sis FS Series Switch Requirements • Keep the client and SAN side networks physically separate, and deploy two switches on each side to protect against a switch failure. • Do not block IPv6 traffic on your SAN/internal switches if you have FS series appliances attached.
Configure Your Microsoft Windows Operating System A This section describes how to configure settings on your Microsoft Windows servers to ensure high availability. Procedure Summary To ensure high availability, configure the settings on your Microsoft Windows servers as follows. If you have installed the Host Integration Tools for Microsoft, skip step 3. 1. Install the recommended Microsoft hotfixes described in 1. Install the Recommended Microsoft Hotfixes. 2.
Hotfix/Link Description of Issue http://support.microsoft.com/kb/4056890 Provides a listing of the Windows 2016 hotfixes and recommended Microsoft updates. To obtain update rollups from Microsoft, go to update.microsoft.com/. Refer to support.microsoft.com/kb/119591 for information about downloading driver software updates and other support files. 2.
Parameter Recommended Value (Decimal) HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class \{4d36e97b-e325-11ce-bfc1-08002be10318}\ \Parameters\ImmediateData 1 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class \{4d36e97b-e325-11ce-bfc1-08002be10318}\ \Parameters\InitialR2T 0 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class \{4d36e97b-e325-11ce-bfc1-08002be10318}\ \Parameters\IPSecConfigTimeout\ 60 HKEY_LOCAL_MACHINE\SYSTEM\Curr
Parameter Recommended Value (Decimal) HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class \{4d36e97b-e325-11ce-bfc1-08002be10318}\ \Parameters\WMIRequestTimeout\ 30 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Disk \TimeOutValue 60 Only Windows Servers with MPIO HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iScsiPrt \Parameters\IoTimeoutValue\ 60 (if using MPIO) HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\mpio \Parameters\AdditionalCriticalWorkerThreads
Parameter Recommended Value (Decimal) HKEY_LOCAL_MACHINE\System\Current ControlSet\Services\mpio \Parameters\UseCustomPathRecoveryInterval 1 4. Verify Microsoft Windows Guidelines Application-Specific Events Applications that run in an iSCSI environment are sometimes directly affected by logging various events. The following section discusses specific applications that might be affected by iSCSI SAN events and settings. NOTE: You might notice some iSCSI SAN messages in the event log.
Enable ICMP Echo Requests for iSCSI Initiators in Windows By default, Windows Firewall does not allow an incoming ICMP Echo message (also known as an ICMP Echo Request message). Dell recommends changing Firewall settings to allow ICMP echo for ICMPv4, or for ICMPv6 if using an IPv6 initiator. See the Windows Firewall documentation for instructions on creating inbound custom rules to allow ICMPv4 and ICMPv6 Echo Request packets.
Configure Your VMware Environment B This section describes how to configure settings on your VMware products, including vSphere and ESX hosts, to ensure high availability. For more detailed information, see Tech Report TR1091, Best Practices for Implementing VMware vSphere in a Dell Equallogic PS Series SAN Environment. This tech report is available from: http://en.community.dell.com/techcenter/extras/m/white_papers/20434601/download.aspx Set iSCSI Login Timeout Value on vSphere 5.1 and 5.
Table 4. Storage Heartbeat Summary lists a summary of heartbeats. Table 4. Storage Heartbeat Summary ESX/ESXi Version iSCSI Login Timeout Value Storage Heartbeat Multipathing Policy ESX/ESXi 4.0 Not applicable 1 Yes RR ESX/ESXi 4.1 Not applicable 1 Yes MEM 4, RR ESX/ESXi 4.1 update 3 60 Yes MEM 4, RR ESXi 5.0 602 Yes MEM 4, RR ESXi 5.1 60 No 3 MEM 4, RR ESXi 5.5 60 No3 MEM 4, RR 1. Under ESXi 4.0 and 4.1, the iSCSI Login Timeout value is set to 15 seconds and cannot be changed.
Configure Your Linux Operating System C This section describes how to configure recommended settings on your Linux hosts to ensure high availability. It also shows how the Host Integration Tools for Linux (HIT/Linux) configure these recommended settings when installed on your Linux hosts. Configure SCSI Device Settings Using the udev Facility The Linux udev utility can be used to dynamically modify device settings every time a new device is added or changed.
which can place a resource burden on both the EqualLogic arrays and the Linux host. Dell recommends that you change the setting to manual. The HIT/Linux eqltune utility recommends this change, but does not automatically implement it. node.startup = manual Configure Linux Networking Dell recommends that you configure multipathing for Ethernet interfaces on a Linux host to connect to an EqualLogic group.
Summary of Recommended Changes Table 5. Summary of Recommended Changes summarizes the changes to Linux settings that are recommended by Dell. Table 5. Summary of Recommended Changes Area Setting Default Value Recommended Value (EQL) SCSI block devices Device timeout 30 seconds 60 seconds Per SCSI device read-ahead buffer 128KB 1024KB Per SCSI device I/O scheduler CFQ noop iSCSI settings node.session.iscsi.FastAbort Yes No iSCSI settings node.
Configure Your Solaris 10 Operating System D You can use the default initiator configuration for Oracle Solaris 10 operating systems. No changes are required. However, you might experience the following issue. Zero-Length Volumes By default, the Solaris 10 initiator automatically connects to all volumes that it discovers. If it connects to a zero-length volume (such as the vss-control volume), it panics.
Configure Your IBM AIX Operating System E IBM AIX systems might experience the following issue. iSCSI Initiators Lose Volume Connectivity In some cases, after a load-balancing operation completes, AIX iSCSI initiators lose volume connectivity. This issue can be corrected by applying a patch to your AIX system. For more information, contact your IBM customer support provider and reference incident number IZ90885, or visit: ibm.com/support/docview.
