IBM-V系统存储-hyperswap实施手册(英文)

1 IBM V 系统存储系统存储 hyperswap 实施手册实施手册 2 文档信息文档信息 文档编号文档编号 IBMIBM SVC 70 SVC 70 文挡名称作者电话 QQ IBM V 系统存储 hyperswap 实施手册朱亚铭 13951968365150111099 文档修订记录文档修订记录 编号修订内容简述修订日期修订前版本号 V1 0 整体文档的编写 2016 12 23 注 技术交流邮箱 ymzhu2005 3 一 一 Configuring an IBM HyperSwap topology system 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 task To access the Modify System Topology wizard select Monitoring System In the Actions menu select Modify System Topology Configuring site information for the system To configure a HyperSwap system topology you must assign enclosures external storage systems and hosts to a specific site Creating HyperSwap volumes 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 Converting an existing volume to a HyperSwap volume 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 二 二 Configuring site information for the system To configure a HyperSwap system topology you must assign enclosures external storage systems and hosts to a specific site 4 2 1 Using the management GUI You 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 CLI You 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 5 numeric ID Enter the following command to create specific names for each site chsite name losangeles 1 In 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 2 chsite name quorum 3 In 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 canister1 chnodecanister site losangeles canister2 Both 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 canister3 chnodecanister site sandiego canister4 In 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 storagesystem1 6 In this example storagesystem1 is assigned to site losangeles To assign a storage system to the other site enter the following command chcontroller site sandiego storagesystem2 In 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 storagesystem3 In 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 host1 In this example host1 is assigned to site losangeles If you have other hosts you can assign them to other sites chhost site sandiego host2 In 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 hyperswap 6 Optionally configure bandwidth settings for the background copy operations between each site by entering the following command chpartnership linkbandwidthmbits 2048 backgroundcopyrate 50 mysystem 7 Background 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 CLI After 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 ipv6 5 target iscsiname iogroup list configured status site id site name 0 1 IP1 IQN1 1 1 1 1 no Full 1 site1 6 From the nodes of site 1 add a session to the discovered targets addiscsitorageport site 1 0 7 From the nodes of site 1 view the established sessions with the target 8 id src port id target ipv4 target ipv6 target iscsiname 9 controller id iogroup list status site id site name 0 3 IP1 IQN1 5 1 1 1 1 full 1 site1 10 The new controller can be shown as available by entering the lscontroller command Assign a site chcontroller site 1 controllerID 11 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 8 三 三 Creating HyperSwap volumes 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 begin Before you create HyperSwap volumes you must configure the HyperSwap topology See Configuring site information for the system for directions 3 2 About this task After you configure the HyperSwap topology complete one of the following steps 3 3 Procedure 1 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 四 Converting an existing volume to a HyperSwap volume 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 9 4 1 Before you begin Before you add a copy of the volume the system must be configured with the HyperSwap system topology 4 2 About this task Using 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 volume5 In 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 configuration 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 10 IP quorum configuration In 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 system A 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 五 Quorum disk configuration 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 11 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 12 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 configurations To 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 13 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 the active quorum disk 4 A new storage system is added to site 3 5 In standard topology the Storwize V5000 administrator must reassign all three quorum disks to ensure that the active quorum disk is now at site 3 again In HyperSwap topology the system automatically assigns the new active quorum disk when the storage system is installed and the site setting is configured 5 2 IP quorum configuration In some HyperSwap configurations IP quorum applications can be used at the third site as an alternative to third site quorum disks No Fibre Channel connectivity at the third site is required to use an IP quorum application as the quorum device The IP quorum application 14 is