The optimal setup to achieve the greatest density of tape drive connectivity is to use external 1x4 mini- SAS to mini-SAS fan out cables to expand the number of tape drives which can be utilized with the Chelsio USR (Figure 3).
Figure 3 - 1x4 mini-SAS to mini-SAS Fan Out External Cable
Each port on the Chelsio USR is a multi-lane x4 SAS port which when coupled with an external 1x4 mini- SAS to mini-SAS fan out cable, allows up to four SAS tape drive connections per Chelsio USR SAS port. Since there are two SAS ports on the Chelsio USR, this allows up to a total of eight SAS tape drives per Chelsio USR purchased.
Additionally, with an x4 mini-SAS cable the full effective 6Gb bandwidth is replicated on each lane of the cable and is never split between the lanes. For example, if a customer connects a single mini-SAS to mini-SAS cable to one PowerVault LTO5 tape drive they will see performance up to 140 MB/s. Alternatively, when the 1x4 mini-SAS to mini-SAS fan out cable is attached to four PowerVault LTO5 tape drives, all four LTO5 tape drives will still see performance up to 140 MB/s. There is an additional gain in drive capacity on the Chelsio USR, but there should be no significant degradation in tape drive performance by using a 1x4 mini-SAS to mini-SAS fan out cable.
If ordered through Dell, the 1x4 mini-SAS to mini-SAS fan out cables which have been tested and qualified with the Chelsio USR and Dell PowerVault tape products can be purchased in a bundle with the Chelsio USR SAS-to-iSCSI appliance.
Configuring the Tape Library through the Chelsio USR Management Interface
Setting up the tape library on the iSCSI SAN through the Chelsio USR is a very quick and easy task, but requires performing a few steps through the Chelsio USR management interface first. The management interface can be accessed through two methods following the initial setup of the Chelsio USR: 1) connecting an Ethernet cable to one of the 1Gb Ethernet ports, and accessing through a web browser or 2) attaching a KVM switch to the VGA, serial or USB port.
Enhancing the Dell iSCSI SAN with Dell PowerVaultTM Tape Libraries and Chelsio Unified Storage Router iSCSI Appliance