Dell PowerVault MD1120 Optimization Manual page 14

A REFERENCE GUIDE FOR OPTIMIZING DELL™ POWERVAULT™ MD1XXX FAMILY SAS SOLUTION
recommended within a single RAID group. PowerVault MD1000 supports 36 GB, 73 GB, 146 GB,
300 GB, and 400 GB capacities for 3.5" SAS physical disks. PowerVault MD1120 supports 36
GB, 73 GB, and 146 GB 2.5" SAS physical disks. When operating in a RAID configuration, the
lowest capacity physical disk defines the RAID virtual disk size. For example, a RAID 1
configuration with two different sized physical disks, one 36 GB and another 146 GB physical disk,
will be limited to 36 GB. If the same two physical disks were configured in RAID 0 configuration, the
virtual disk size would be limited to 73 GB (the equivalent of two 36 GB physical disks in RAID 0
configuration).
For the latest information on support for specific physical disks, see the Dell Storage web site at:
http://www.us.dell.com/storage/
Mixing Physical Disk Spindle Speeds
Mixing different physical disk spindle speeds is supported, but not recommended within a single
RAID group. PowerVault MD1xxx Family storage enclosures support 10,000 and 15,000 RPM
spindle speeds. Depending upon the RAID configuration, the lowest spindle speed may dictate the
maximum performance of the RAID group.
SCSI Enclosure Services (SES)
The EMM continuously monitors environmental variables such as temperature and voltage.
PowerVault MD1xxx Family storage enclosures work in conjunction with Dell OpenManage Server
Administrator to set trigger thresholds that warn the user when these variables exceed safe
operating levels. The enclosure will automatically power down when these environmental variables
exceed a critical threshold level in order to avoid potential equipment damage. Both local visual
indicators (for example, LEDs) and audio alerts are triggered when faults are detected. The audio
alerts on the enclosure are disabled by default, but can be enabled using Server Administrator. The
following SES functions are provided by the EMMs in the PowerVault MD1xxx Family storage
enclosures:
•
Enclosure shelf faults detection
•
Physical disk Power/Fault/Offline status
•
Power supply status and shutdown capabilities
•
Fan speed status and control
•
Temperature monitoring
•
Over/under temperature shutdown capabilities
•
Alarms (local audible and visual LED indicators)
Hot Plugging
•
PowerVault MD1xxx Family storage enclosures are designed for hot plugging certain
components to prevent damage when pulling or replacing. Hot plugging is a concept
which allows for the safe removal and replacement of components while the power is still
on. Hot plugging allows server applications and disk activities to continue uninterrupted,
while maintenance or repair actions take place. Additional steps may be required for
physical disks to become usable. See the RAID controller User's Guide for more
information.
•
Hot Pluggable Devices
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Physical disk (all Disk I/O activities must be halted first)
o
Power supply module/ cooling fan module
o
VER A02
6/16/2008