IBM V系統(tǒng)存儲 hyperswap實(shí)施手冊(英文).doc

IBM V系統(tǒng)存儲 hyperswap實(shí)施手冊文檔信息(文檔編號IBM SVC-70)文擋名稱作者電話QQIBM V系統(tǒng)存儲 hyperswap實(shí)施手冊朱亞銘13951968365150111099文檔修訂記錄編號修訂內(nèi)容簡述修訂日期修訂前版本號V1.0整體文檔的編寫2016.12.23注：技術(shù)交流郵箱 一、Configuring an IBM HyperSwap topology system窗體頂端窗體底端A HyperSwap topology system assists with high availability and site disaster recovery. A HyperSwap topology system can be configured through site allocation and topology change command-line (CLI) commands. The management GUI configures a HyperSwap topology with the Modify System Topology wizard, which guides you through all the steps easily.1.1 About this taskTo access the Modify System Topology wizard, select Monitoring System. In the Actions menu, select Modify System Topology. Configuring site information for the systemTo configure a HyperSwap system topology, you must assign enclosures, external storage systems, and hosts to a specific site. Creating HyperSwap volumesYou can use the management GUI or the command-line interface (CLI) to create HyperSwap volumes. A HyperSwap volume has one copy on each site. Converting an existing volume to a HyperSwap volumeYou can use the management GUI or the command-line interface to convert a basic volume to a HyperSwap volume. You convert the basic volume by adding another copy of the volume in a second site. 二、Configuring site information for the system 窗體頂端窗體底端To configure a HyperSwap system topology, you must assign enclosures, external storage systems, and hosts to a specific site.2.1 Using the management GUIYou can use the Modify System Topology wizard in the management GUI to easily configure the site names and assign objects on your system to a site. The Modify Topology wizard automatically detects any Fibre Channel-attached storage, but iSCSI storage must be added manually before the site assignments can be configured. You can use either the management GUI or the command-line interface to add Storwize systems. Dell EqualLogfic systems can be configured with the command-line interface only. Complete the following steps to configure the topology for the system and to optionally add iSCSI-attached storage:1. In the management GUI, select Monitoring System. In the Actions menu, select Modify System Topology.2. Follow the wizard to complete the configuration of the HyperSwap topology. 3. If you are using iSCSI-attached external storage, you must add the storage to the system and specify the site using the Add iSCSI External Storage wizard. To access the wizard, select Pools External Storage Add iSCSI External Storage. 4. Select IBM Storwize as the external storage system that you are adding. The system supports iSCSI connections to Storwize family products and to Dell Equallogic systems, but you must configure Dell EqualLogic systems with the command-line interface. 5. Enter the information for the source and target ports for the iSCSI connection and specify the site for the iSCSI-attached storage.2.2 Using the CLIYou can also use the command-line interface to configure site information and configure the system as a HyperSwap topology. Separate commands are used for each configuring site definitions for the necessary objects on the system. Although you do not need to name sites, creating names that are based on the location or use of the site simplifies management of the HyperSwap topology. Complete the following steps to configure site information and set the system as a HyperSwap topology:1. For easier management of the HyperSwap topology, create specific names for each site on the system. If names are not specified, sites can be referred to by their default name or numeric ID. Enter the following command to create specific names for each site. chsite -name losangeles 1In this example, site 1 is now named losangeles. To rename the other sites in the HyperSwap topology, issue the same command with names for the other sites:chsite -name sandiego 2chsite -name quorum 3In this example, site 2 is now named sandiego and site 3 is named quorum. Note: IP quorum applications can be used at a third site to provide a tie-break if there is a loss of connectivity between site 1 and site 2. For more information, see the IP quorum configuration information.2. Enter the following commands to assign existing node canisters in each control enclosure (I/O group) to sites:chnodecanister -site losangeles canister1chnodecanister -site losangeles canister2Both node canisters in a control enclosure must be assigned to the same site. In this example, the I/O group that contains canister1 and canister2 are assigned to the site losangeles. To assign the node canisters in another I/O group to the other site, enter the following commands:chnodecanister -site sandiego canister3chnodecanister -site sandiego canister4In this example, the I/O group that contains canister3 and canister4 are assigned to the site sandiego. You must assign a site for all node canisters in the system.3. Enter the following command to assign existing external storage systems to sites: chcontroller site losangeles storagesystem1In this example, storagesystem1 is assigned to site losangeles. To assign a storage system to the other site, enter the following command:chcontroller site sandiego storagesystem2In this example, storagesystem2 is assigned to site sandiego. If you plan to use an external storage system to provide quorum, then you must assign that to the third site. Alternatively, an IP quorum application can be used to provide quorum. For more information, see the IP quorum configuration information. To assign an external storage system to the third site, enter the following command: chcontroller site quorum storagesystem3In this example, storagesystem3 is assigned to site quorum.You must assign a site for all storage systems that are present in the configuration.4. Enter the following command to assign existing hosts to sites:chhost -site losangeles host1In this example, host1 is assigned to site losangeles. If you have other hosts, you can assign them to other sites:chhost -site sandiego host2In this example, host2 is assigned to site sandiego. 5. After all the site assignments are complete for enclosures, storage systems, and hosts, set the system topology to HyperSwap by entering the following command:chsystem -topology hyperswap6. Optionally, configure bandwidth settings for the background copy operations between each site by entering the following command:chpartnership -linkbandwidthmbits 2048 -backgroundcopyrate 50 mysystemBackground copy is the term that is used for the initial synchronization and any subsequent resynchronization traffic for HyperSwap volumes in the system. After you complete these steps, you can configure HyperSwap volumes to create copies at each site. 2.3 Configuring an external iSCSI controller using the CLIAfter you change the system topology to hyperswap and nodes are assigned sites, you can configure an external iSCSI controller by completing the following steps. 1. From the nodes of site 1, discover the iSCSI target controller:2. detectiscsistorageportcandidate srcportid 1 -targetip IP1 -site 1 3. Check the status of the discovered targets:4. lsiscsistorageportcandidate id src_port_id target_ipv4 | target_ipv65. target_iscsiname iogroup_list configured status site_id site_name 0 1 IP1 IQN1 1:1:1:1 no Full 1 site16. From the nodes of site 1, add a session to the discovered targets: addiscsitorageport -site 1 07. From the nodes of site 1, view the established sessions with the target:8. id src_port_id target_ipv4 | target_ipv6 target_iscsiname9. controller_id iogroup_list status site_id site_name 0 3 IP1 IQN1 5 1:1:1:1 full 1 site110. The new controller can be shown as available by entering the lscontroller command. Assign a site:chcontroller -site 1 controllerID11. From the system nodes of site 2, repeat steps 1 through 5 for discovering and establishing sessions to the same iSCSI controller or a different iSCSI controller. 三、Creating HyperSwap volumes窗體頂端窗體底端You can use the management GUI or the command-line interface (CLI) to create HyperSwap volumes. A HyperSwap volume has one copy on each site.3.1 Before you beginBefore you create HyperSwap volumes, you must configure the HyperSwap topology. See Configuring site information for the system for directions.3.2 About this taskAfter you configure the HyperSwap topology, complete one of the following steps.3.3 Procedure1. If you are using the management GUI, use the Create Volumes wizard to create HyperSwap volumes. 2. If you are using the command-line interface, use the mkvolume command to create a volume. For example, a HyperSwap volume is created by specifying two storage pools in independent sites. mkvolume -size 100 -pool site1pool:site2pool四、Converting an existing volume to a HyperSwap volume窗體頂端窗體底端You can use the management GUI or the command-line interface to convert a basic volume to a HyperSwap volume. You convert the basic volume by adding another copy of the volume in a second site. 4.1 Before you beginBefore you add a copy of the volume, the system must be configured with the HyperSwap system topology. 4.2 About this taskUsing the management GUI: To change a basic volume to a HyperSwap volume in the management GUI, select Volumes, right-click the basic volume, and select Add Volume Copies. Add a copy in a different site to the existing copy.Using the command-line interface (CLI):In the CLI, the addvolumecopy command adds a copy to a HyperSwap volume, which changes a basic volume into a HyperSwap volume with copies on two separate sites. To add a copy to a basic volume to convert it to a HyperSwap volume, enter the following command:addvolumecopy -pool site2pool volume5In this example, site2pool is the storage pool on the other site. A quorum disk is an MDisk or a managed drive that contains a reserved area that is used exclusively for system management. A system uses a quorum disk for two purposes: To break a tie when a SAN fault occurs, when exactly half of the nodes that were previously a member of the system are present. To hold a copy of important system configuration data. Just over 256 MB is reserved for this purpose on each quorum disk candidate. Quorum disk configurationA clustered system automatically assigns quorum disk candidates. When you add new storage to a system or remove existing storage, however, it is a good practice to review the quorum disk assignments. IP quorum configurationIn some HyperSwap configurations, IP quorum applications can be used at the third site as an alternative to third-site quorum disks. Manual quorum disk override in a HyperSwap systemA manual quorum disk override is required when you experience a rolling disaster. In rare situations, the system is subject to what is referred to as a rolling disaster. A rolling disaster occurs when an incident has wide scope, and its effects are felt in multiple steps over an extended time period. The following example scenario describes a rolling disaster and shows how to recover from that rolling disaster.五、Quorum disk configuration窗體頂端窗體底端A clustered system automatically assigns quorum disk candidates. When you add new storage to a system or remove existing storage, however, it is a good practice to review the quorum disk assignments. It is possible for a system to split into two groups where each group contains half the original number of nodes in the system. A quorum disk determines which group of nodes stops operating and processing I/O requests. In this tie-break situation, the first group of nodes that accesses the quorum disk is marked as the owner of the quorum disk and as a result continues to operate as the system, handling all I/O requests. If the other group of nodes cannot access the quorum disk or finds the quorum disk is owned by another group of nodes , it stops operating as the system and does not handle I/O requests.A system can have only one active quorum disk that is used for a tie-break situation. However, the system uses three quorum disks to record a backup of system configuration data to be used in the event of a disaster. The system automatically selects one active quorum disk from these three disks. The active quorum disk can be specified by using the chquorum command-line interface (CLI) command with the active parameter. To view the current quorum disk status, use the lsquorum command.The other quorum disk candidates provide redundancy if the active quorum disk fails before a system is partitioned. To avoid the possibility of losing all the quorum disk candidates with a single failure, assign quorum disk candidates on multiple storage systems.Note: Mirrored volumes can be taken offline if no quorum disk is available. The synchronization status for mirrored volumes is recorded on the quorum disk.Important: Make sure that you move any quorum disks to a different controller before you do maintenance on a service controller.In a Storwize V5000 system with a single control enclosure or without any external managed disks, quorum is automatically assigned to drives. In this scenario, manual configuration of the quorum disks is not required. In a system with two or more I/O groups, the drives are physically connected to only some of the node canisters. In such a configuration, drives cannot act as tie-break quorum disks; however, they can still be used to back up metadata.If suitable external MDisks are available, these MDisks are automatically used as quorum disks that do support tie-break situations.If no suitable external MDisks exist, the entire system might become unavailable if exactly half the node canisters in the system become inaccessible (such as due to hardware failure or becoming disconnected from the fabric).In systems with exactly two control enclosures, an uncontrolled shutdown of a control enclosure might lead to the entire system becoming unavailable because two node canisters become inaccessible simultaneously. It is therefore vital that node canisters are shut down in a controlled way when maintenance is required.Quorum configuration is chosen by the following criteria: The drive is redundant and stable. The drives are in a control enclosure. No unrecoverable errors are logged against the drive Quorum is distributed among the available control enclosures. Flash drives are avoided. Nearline hard disk drives are avoided. Drive use in order of priority is spare, candidate, and then member.These criteria are not requirements. On configurations where meeting all the criteria is not possible, quorum still is automatically configured.It is possible to assign quorum disks to alternative drives by using the chquorum command. However, you cannot move quorum to a drive that creates a less optimum configuration. You can override the dynamic quorum selection by using the override yes option of the chquorum command. This option is not advised, however, unless you are working with your support center.When you change the managed disks that are assigned as quorum candidate disks, follow these general guidelines: When you use quorum drives, use drives from the control enclosure when possible for the best available performance and connectivity. If no external MDisks are available, at least one drive and ideally three drives in the control enclosure must be present and have a use that is not unused or failed. When you use SAN-attached quorum MDisks, aim to distribute the quorum candidate disks so that each MDisk is provided by a different storage system. For information about which storage systems are supported for quorum disk use, refer to the supported hardware list. Before you issue the chquorum command, ensure the status of the MDisk or drive that is being assigned as a quorum candidate disk is reported as online. Use smaller capacity MDisks, or use drives as the quorum devices, to significantly reduce the amount of time that might be needed to run a recover system procedure (also known as Tier 3 or T3 recovery), if necessary.5.1 Quorum MDisks or drives in HyperSwap system configurationsTo provide protection against failures that affect an entire location (for example, a power failure), you can use active-active relationships with a configuration that splits a single clustered system between two physical locations. For more information, see HyperSwap configuration details. For detailed guidance about HyperSwap system configuration for high-availability purposes, contact your IBM regional advanced technical specialist.If you configure a HyperSwap system, the system automatically selects quorum disks that are placed in each of the three sites.The following scenarios describe examples that result in changes to the active quorum disk: Scenario 1:1. Site 3 is either powered off or connectivity to the site is broken.2. If topology is standard, the system selects a quorum disk candidate at site 2 to become the active quorum disk. If topology is HyperSwap, the system operates without any active quorum disk.3. Site 3 is either powered on or connectivity to the site is restored. 4. Assuming that the system was correctly configured initially, Storwize V5000 automatically recovers the configuration when the power is restored. Scenario 2:1. The storage system that is hosting the preferred quorum disk at site 3 is removed from the configuration.2. If possible, the system automatically configures a new quorum disk candidate. 3. In HyperSwap topology, the system selects only a new quorum disk that is in site 3. In a standard topology, the system selects a quorum disk candidate at site 1 or 2 to become