Dell POWERVAULT MD1000 - Manual (Page 6)

A REFERENCE GUIDE FOR OPTIMIZING DELL™ MD1000 SAS SOLUTIONS VER A00
PAGE 6 5/06/2005
Figure 2: Bandwidth improvement with SAS port aggregation
Improved capacity scalability
•
SAS allows for port expansion, enabling the ability to “daisy-chain” storage enclosures for
dramatic improvements in capacity scalability. With Ultra320 SCSI, systems were limited to a
maximum of 16 devices on a single SCSI channel. This typically translated to maximum of 14
physical disks connected to a single SCSI channel on a RAID controller. With SAS expansion,
a single SAS port can be expanded out to multiple SAS devices (similar to how Ethernet hubs
can expand a single Ethernet connection into multiple devices).
Other important changes to keep in mind about SAS:
•
SAS continues to use the SCSI command sets for driver & software compatibility.
• SAS is not backwards compatible with Parallel SCSI.
2. Recommended Maintenance for your Dell PowerVault MD1000 SAS Solution
Dell strives to provide the best possible customer experience for all of our enterprise server and
storage products. Proper maintenance of your solution is essential to help ensure that the
equipment remains in optimal working condition. Dell recommends the following suggested
maintenance activities.
Keep firmware/drivers/utilities up to date
In general, Dell posts planned maintenance updates for firmware twice a year. To stay current
with the latest updates, customers can subscribe to Dell notification tools. Click the following link
to sign up for technical updates.
One parallel SCSI cable
Up to 320MB/s
performance
One x4 SAS cable
Up to 12.0 Gbps performance