Cisco Cisco UCS C460 M2 High-Performance Rack Server White Paper
6 © 2016 Cisco and/or its affiliates. All rights reserved.
Figure 5. RAID 0 Group with Two Virtual Drives in Cisco UCS B200 M4 Server
The two 32-GB FlexFlash SD cards are configured for mirroring (RAID 1) in the Cisco UCS service profile’s local disk
configuration policy.
configuration policy.
The ESXi OS is installed on the FlexFlash SD. The VSA deployment uses the 185-GB virtual disk and must be configured as
persistent storage on the ESXi host. The second virtual drive is allocated explicitly to the VSA in a raw disk mapping. The VSA
sees the virtual disk as a pool of storage from which iSCSI targets can be carved. These iSCSI targets can be mirrored with other
VSAs to create highly available storage.
persistent storage on the ESXi host. The second virtual drive is allocated explicitly to the VSA in a raw disk mapping. The VSA
sees the virtual disk as a pool of storage from which iSCSI targets can be carved. These iSCSI targets can be mirrored with other
VSAs to create highly available storage.
This deployment uses four mirror volumes: two mirror volumes between each pair of SvSAN VSAs, as shown in Figure 6. All
iSCSI mirror volumes are presented to all ESXi hosts, but mirroring occurs only between a pair of SvSAN VSAs.
iSCSI mirror volumes are presented to all ESXi hosts, but mirroring occurs only between a pair of SvSAN VSAs.
A mirrored target is a target that is mirrored between a pair of VSAs. Therefore, there are two identical copies of the target data
when the system is running normally: one on each VSA. Any data sent to one copy, or plex, is automatically copied to the other.
This copying is performed synchronously, so that if an initiator sends data to one plex, the VSA does not acknowledge the request
until the data is present on both plexes. A synchronous mirror can be used to provide highly available storage, because an initiator
can access any plex at any time, and if one plex fails, the initiator can continue without interruption by using the other plex.
when the system is running normally: one on each VSA. Any data sent to one copy, or plex, is automatically copied to the other.
This copying is performed synchronously, so that if an initiator sends data to one plex, the VSA does not acknowledge the request
until the data is present on both plexes. A synchronous mirror can be used to provide highly available storage, because an initiator
can access any plex at any time, and if one plex fails, the initiator can continue without interruption by using the other plex.
Figure 6. StorMagic SvSAN Mirror Target with Four Cisco UCS B200 M4 Servers
VD 2
2TB
ESXi Boot
Drive
ESXi Boot
Drive
VMware vSphere Cluster
2 x 1.2TB RAIDO
VD 1
185GB
ESXi
ESXi
VD 1
185GB
2 x 1.2TB RAIDO
VD 2
2TB
VSA
Local VMFS
VSA
Local VMFS
Shared
VMFS
Shared
VMFS
VD 2
2TB
ESXi Boot
Drive
ESXi Boot
Drive
2 x Synchronous Mirrors
2 x 32GB SD card
Hypervisor (HV)
Partition Mirror
2 x 1.2TB RAIDO
VD 1
185GB
ESXi
ESXi
VD 1
185GB
2 x 1.2TB RAIDO
VD 2
2TB
VSA
Local VMFS
VSA
Local VMFS
Shared
VMFS
Shared
VMFS