lsi megaraid storage manager in safe mode

This could be risky when the power is cut to the system and the cache is lost. If the data fits in the cache the drives will not be spun up. The Dimmer Switch power save mode that the LSI MegaRAID is capable of (but only with Firmware v12.12.0-0048 from Sun/Oracle) also has the ability to cache activity to the drives while in power save mode. This is not meant for disks being accesses heavily 24/7. If you were booted in DOS, the drives would still power down. The only drawback is that spindled drives do take a few seconds to wind back up, so don’t expect instant access to your data. I know most OS’s can do all this, turn drives off with power settings adjustments etc. But this is done via the controller. Firmware version 12.12.0-0048 for Sun/ Oracle brings us the ability to power save active drives also. Active drives are the drives in use and shown to the OS in an array be it single drive RAID 0 or a multi-drive RAID array. The LSI SAS 2108 is capable of power save mode for non-active and hot spare drives. All LSI SAS 2108 fimrware versions have these 2 options for power save mode. Once the drives go into power save mode, there is a definite quieting from the server. The disk noise is not excessive but audible all the same. Hitachi 7k200 drives are known for good performance and reliability but also noise. That equals about $83.22 per year, just to keep the hard drives idle. $83 I can spend on other things like one beer a month for a year. The RAID controller will be an LSI SAS 2108 based card.Ĥ5.6w at idle may not seem like a big deal as they consume about the same as 2x energy efficient light bulbs. Over a year it ads up. Let’s say 20 hours of idle a day = 912whr per day * 365 = 332.88Kwhr per year. In NZ each kwhr = about $0.25. Since money is not growing on trees, I need to keep the power bill to a minimum. My system main storage will be: 6x 2TB Hitachi 7k2000 Hard Drives in RAID5 each using 7.6w at idle = 45.6w total, I may at some point get 2 more and go RAID6. As I’m slowly setting up my new Home Server build, I’m starting to think about the long term use of the server. Its going to be on 24/7. SAS 2108 cards can be found inexpensively as the IBM ServeRAID M5014 deal shows us. For those wondering, the LSI SAS 2108 is an 8 port SAS 6.0gbps controller that supports parity RAID functions such as RAID 5. Today we are going to look at the LSI SAS 2108 power save feature for Active and Configured drives.

Lsi megaraid storage manager in safe mode