Installing a compute node

• Windows Server(64bits)
• Red Hat Enterprise Linux(64bits)
• VMware ESXi

Multipath setting

(Linux Device Mapper - Multipath)

• The retry count setting (no_path_retry) for the same path is 6 or more.
• The path polling interval (polling_interval) setting value is 30 or more.
• The setting value of fast_io_fail_tmo is other than off.³
• The setting value of dev_loss_tmo is the OS maximum value.⁴
• The failback setting is "immediate."⁵
• The path_checker setting is readsector0.⁶
• The hardware_handler setting is 0.⁷

In the case of iSCSI connection, this must be the same as the setting value of ComputeNWMTUSize in the VSSB configuration file.⁸

• (Bare metal) This must be the same as the setting value of ComputeNWMTUSize in the VSSB configuration file.

• (Cloud) This must be 9000 or more.

1. For details about the supported versions, contact customer support.
2. The SCSI Timeout setting value is the time until the OS determines that a SCSI command has not responded. When the OS detects no response to the SCSI command, it performs recovery processing for the failed path. If the failed path cannot be recovered by the recovery process, the path is blocked and switched to another path. During the recovery process, I/O operations for the relevant path are stopped. Therefore, in the application layer timeout design, it is necessary to consider the recovery processing time in addition to the SCSI Timeout setting value.
3. The default value for fast_io_fail_tmo is 5. When set to off, path switching does not occur until dev_loss_tmo seconds have elapsed when a path failure occurs, and it does not operate as expected.
4. The maximum value depends on your distribution. See your distribution document for the maximum value.
5. Set the failback policy ("failback") of the path group to "immediate" (immediate failback). If the failback policy is not set to "immediate", I/O will still be issued to the non-priority path after recovery from a path fault, thus requiring a manual path switch operation.
6. If a failure occurs in a storage node of VSP One SDS Block, when a value other than readsector0 is set, paths might be wrongly blocked. For this reason, verify that you set readsector0.
7. If a value other than 0 is set, multipath might not operate as expected depending on OS versions of the compute node.
8. In the case of FC connection, this value does not have to be the same as the setting value of ComputeNWMTUSize because ComputeNWMTUSize is not used.

• Red Hat Enterprise Linux(64bits)
• VMware ESXi

• Native NVMe Multipath must be enabled.³
• The I/O policy setting for the NVMe device must be round-robin.
• ctrl_loss_tmo must be set to -1.⁴

1. For details about the supported versions, contact customer support.
2. The NVMe Timeout setting value is the time until the OS determines that no response is returned for the NVMe command. When the OS detects no response to an NVMe command, it performs recovery processing for the failed path. If the recovery processing does not recover the failed path, the path is blocked and switched to another path. During the recovery process, I/O operations to and from the path are stopped. Therefore, you need to consider the time it takes for the OS to perform recovery processing in addition to the NVMe Timeout setting when you design timeout for the application layer.
3. When Native NVMe Multipath is enabled, Asymmetric Namespace Access (ANA) is applied to all volumes. For details about ANA, see ANA configuration guidelines.
4. When ctrl_loss_tmo is set to -1, path detection will be retried indefinitely if a path loss occurs.

Block Zeroing

When a virtual machine is created, blocks are formatted (zeroed out). This primitive enables the storage to perform this procedure, speeding up provisioning of virtual machines. When used with the thin provisioning feature, the primitive can free the block areas that are usually reserved when a virtual machine is created, enabling efficient use of disk capacity.

Supported

Hardware Assisted Locking

If multiple virtual machines share one VMFS volume in your environment, SCSI reservation conflicts might occur and performance might degrade when Storage vMotion or a virtual machine is turned on. With this primitive, you can avoid such a problem. The primitive offers efficient locking.

Supported

Full Copy

Traditionally, VMware ESXi copy data between volumes. This primitive offloads the operation to the storage, greatly reducing the time required for virtual machine cloning and Storage vMotion processing.

Not supported