Christopher, > [root at daisy cron.daily]# tw_cli /c8 show > Unit UnitType Status %RCmpl %V/I/M Stripe Size(GB) Cache > AVrfy > ------------------------------------------------------------------------------ > u0 RAID-5 OK - - 256K 11175.8 Ri ON > VPort Status Unit Size Type Phy Encl-Slot Model > ------------------------------------------------------------------------------ > p0 OK u0 3.63 TB SATA 0 - WDC > WD4005FZBX-00K5 > p1 OK u0 3.63 TB SATA 1 - WDC > WD4005FZBX-00K5 > p2 OK u0 3.63 TB SATA 2 - WDC > WD4005FZBX-00K5 > p3 OK u0 3.63 TB SATA 3 - WDC > WD4005FZBX-00K5 you are running your RAID-controller without BBU and without write caching. (see the Ri statement) I get tw_cli /c0 show Unit UnitType Status %RCmpl %V/I/M Stripe Size(GB) Cache AVrfy ------------------------------------------------------------------------------ u0 RAID-6 OK - - 256K 16763.7 RiW ON VPort Status Unit Size Type Phy Encl-Slot Model ------------------------------------------------------------------------------ p0 OK u0 2.73 TB SATA 0 - WDC WD30EURS-63SPKY0 p1 OK u0 2.73 TB SATA 1 - WDC WD30EURS-63R8UY0 p2 OK u0 2.73 TB SATA 2 - WDC WD30EURS-63SPKY0 p3 OK u0 2.73 TB SATA 3 - WDC WD30EURS-63SPKY0 p4 OK u0 2.73 TB SATA 4 - WDC WD30EURS-63SPKY0 p5 OK u0 2.73 TB SATA 5 - WDC WD30EURS-63SPKY0 p6 OK u0 2.73 TB SATA 6 - WDC WD30EURS-63SPKY0 p7 OK u0 2.73 TB SATA 7 - WDC WD30EURS-63SPKY0 Name OnlineState BBUReady Status Volt Temp Hours LastCapTest --------------------------------------------------------------------------- bbu On Yes OK OK OK 197 31-Dec-2019 with the same type of controllers. When I did the initial installation, I found that the write caching makes a VERY big difference in my mailserver application. However, you might have get problems finding a matching BBU these days if your controller is not very recent. And depending on where you are located and how good your power supply is, you don't want to activate write caching without a BBU. cheers, --- Michael Schumacher