Specifications

ES/OL
Evaluator Series On-Line™
Storage Systems
Product Analysis
May, 2011
Page 11 of 30
Analysis of Fujitsu ETERNUS DX400 S2
Models DX410 and DX440
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Evaluator Group Comments: The encryption capabilities of the Fujitsu ETERNUS DX400 S2 can be of
significant importance where security is required.
Additionally, the ETERNUS DX400 S2 supports encryption during replication using standard IPsec security
(AES encryption with HMAC-MD5 authentication). This feature is enabled through the use of the optional
iSCSI Remote Adapter for remote replication. For more information see the Remote Replication section on
page 24 in this document.
Mirrored Cache
The controllers each contain cache. Only write data is mirrored from one controller to another controller. With
a varying amount of write data, the amount of cache available between the controllers is also variable.
The write data is mirrored between the two controllers over a shared PCI-Express bus link. The bandwidth of
the cache on a controller is not specified by Fujitsu. Table 5 below describes the number of controllers and
cache capacities for the ETERNUS models.
Battery
ETERNUS DX410 S2 and DX440 S2 protect write data in cache memory that has not yet been written to its
intended target drive at the time of a power fault by keeping battery power applied to the controllers long
enough so that the write cache data is safely stored in SSD on each of the controllers. Later, after the power
fault has been cleared and power has been reapplied to the subsystem, the write data is restored to cache
memory and the write data is then correctly written to its original target disk drives.
Battery life is specified at two and a half to three years. The batteries must be replaced if the expiration date
has passed. The expiration date can be read through the ETERNUSmgr web-based software.
LUN Management
Fujitsu refers to their LUN masking and LUN management features as ‘Host Affinity’. Some vendors term this
feature LUN Masking, or LUN Management, or LUN Mapping. LUN access or Host Affinity is controlled by the
ETERNUSmgr configuration software, which is included with the system. Host Affinity controls LUN access,
which provides a security mechanism at the LUN level. A Host Affinity group is defined as a set of LUNs that
are made available to a specific set of servers. The server is identified by the World Wide Name of the host
bus adapter.
LUNs can be assigned to multiple servers, with one LUN used in different Host Affinity groups allowing for
multi-host data access for cluster or other configurations using host software to coordinate data sharing.
A LUN may be comprised of parts of one or more RAID groups, or a partial RAID group.
Virtual / Thin Provisioning
Fujitsu has added support for virtual capacity of volumes, which is known as “Thin Provisioning.” Additionally,
Fujitsu supports expansion of a LUN through “Logical Device Expansion” or LDE.