Multipathing
Increase max bandwidth by adding additional paths (iSCSI only)
In order to achieve maximum throughput Zadara recommends creating a minimum of 4 paths to each iSCSI device (8 optimal). See the following guide for additional information
VMware—Increase iSCSI Bandwidth by Adding Additional Paths
**note: We have observed that adding additional paths will not provide meaningful performance benefits unless the Round Robin IOPS limit is set to 1 (see below)
Path Selection Policy = Round Robin
For best performance Zadara recommends to use the Round Robin path selection policy. With Round Robin the host uses an automatic path selection algorithm rotating through all active paths, instead of a fixed or most recently used path.
Path selection policies are configured on a per-device basis in VMWare.
- Set Round Robin on single device—VMware - Set Multipathing Path Selection Policy on Single Device
- Set Round Robin on all devices—VMware - Set Round Robin multipathing on all Zadara devices
**note: We have observed that setting the path selection policy to Round Robin will not provide meaningful performance benefits unless the Round Robin IOPS limit is set to 1 (see below)
Round Robin IOPS Limit = 1
When using the Round Robin Path Selection Policy it is critical, for performance reasons, to change the Round Robin IOPS limit to 1 (default is 1000). This setting will determine the number of IOPS VMWare will issue before switching to the next available path.
VMware - Set Round Robin IOPS Limit for all Zadara Devices
Set Active-Passive NMP SATP claim rule
To ensure smooth storage failovers it's important that iSCSI connections to Zadara storage are using an Active-Passive connection and not Active-Active. This can be accomplished by defining an NMP SATP claim rule.
Please consult the VMWare documentation for details:
See the following example for reference:
esxcli storage nmp satp rule add -V Zadara -s VMW_SATP_DEFAULT_AP -P VMW_PSP_RR -o action_OnRetryErrors=off
iSCSI Initiator Settings
Zadara Storage recommends that this and that be set according to VMware ESXi Initiator settings for iSCSI