On 09.10.2013 10:39, Kaushal Shriyan wrote: > On Tue, Oct 8, 2013 at 3:45 PM, Dennis Jacobfeuerborn <dennisml at conversis.de >> wrote: > >> On 08.10.2013 07:25, Kaushal Shriyan wrote: >>> Hi, >>> >>> I am planning to install CentOS 6.4 on Dell R720 which has hardware raid >>> card and 6 hard disk slots available. >>> >>> I have planned with the below set up :- >>> >>> *2 Hard disks configured in RAID 1 for installing OS >>> * >>> *4 Hard disks configured in RAID 10 for data drive.* >>> >>> Please suggest and recommend if the above approach is correct and let me >>> know if i am missing anything which is crucial to set up a production >>> server. This server will host MySQL DB server. >> >> Is there any particular reason why you want to create two RAIDs? >> Creating one 6 Disk RAID-10 would give you better random IOPS which is >> useful for a DB System. You can still create two independent virtual >> disks in that case or use independent partitions/LVM volumes to separate >> OS from Data. >> > > Hi Dennis > > Thanks for the reply and not sure i understand *"You can still create two > independent virtual disks in that case"* Please explain. Hi Kaushal, I'm not that familiar with the Dell RAID tools but I know the PERC controllers they use are just rebranded LSI controllers. On an LSI controller you can go into the WebBIOS and define your drive configuration (i.e. create a RAID-10 using drivegroups and spans) and then define virtual disks on top of that. For example you can use 6*1TB disks to form a 3TB RAID-10 and then define a 20G virtual disk for the OS and use the remaining space for a data virtual disk. Back in the days there was no distinction between a RAID and a virtual disk. The RAID *was* the virtual disk. On modern controllers the definition of the RAID topology and the definition of virtual disks on top of that are usually two independent steps. Regards, Dennis