Dell 2850 servers come with the RAID card PERC 4e/Di which is the same as LSI MegaRAID 320-2X . cissutil command doesnt work with Dell Servers. Use the following commands :

# megarc ?

The above command lists all the options available with megarc

# megarc -disPR help

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MEGARC MegaRAID Configuration Utility(LINUX)-1.11(12-07-2004)
By LSI Logic Corp.,USA
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[Note: For SATA-2, 4 and 6 channel controllers, please specify
Ch=0 Id=0..15 for specifying physical drive(Ch=channel, Id=Target)]

Type ? as command line arg for help

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usage :
cmd -disPR|-enPRauto|-enPRman -aX
: Enable/Disable PR on adp X
Refer to Patrol Read docs at LSI for more info
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where :
cmd : name of the utility
-aX : adapter number X(max 12 adapters). X=0..11
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This gets the details about the sub command disPR

# megarc -dispCfg -a0

**********************************************************************
MEGARC MegaRAID Configuration Utility(LINUX)-1.11(12-07-2004)
By LSI Logic Corp.,USA
**********************************************************************
[Note: For SATA-2, 4 and 6 channel controllers, please specify
Ch=0 Id=0..15 for specifying physical drive(Ch=channel, Id=Target)]

Type ? as command line arg for help

Finding Devices On Each MegaRAID Adapter…
Scanning Ha 0, Chnl 1 Target 15

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Existing Logical Drive Information
By LSI Logic Corp.,USA
**********************************************************************
[Note: For SATA-2, 4 and 6 channel controllers, please specify
Ch=0 Id=0..15 for specifying physical drive(Ch=channel, Id=Target)]

Logical Drive : 0( Adapter: 0 ): Status: OPTIMAL
—————————————————
SpanDepth :01 RaidLevel: 5 RdAhead : Adaptive Cache: DirectIo
StripSz :064KB Stripes : 6 WrPolicy: WriteBack

Logical Drive 0 : SpanLevel_0 Disks
Chnl Target StartBlock Blocks Physical Target Status
—- —— ———- —— ———————-
0 00 0×00000000 0×0887c000 ONLINE
0 01 0×00000000 0×0887c000 ONLINE
0 02 0×00000000 0×0887c000 ONLINE
0 03 0×00000000 0×0887c000 ONLINE
0 04 0×00000000 0×0887c000 ONLINE
0 05 0×00000000 0×0887c000 ONLINE

This gets the details of the raid config that has been setup on the box.

# megarc -AllAdpInfo

**********************************************************************
MEGARC MegaRAID Configuration Utility(LINUX)-1.11(12-07-2004)
By LSI Logic Corp.,USA
**********************************************************************
[Note: For SATA-2, 4 and 6 channel controllers, please specify
Ch=0 Id=0..15 for specifying physical drive(Ch=channel, Id=Target)]

Type ? as command line arg for help

AdapterNo FirmwareType CardType
00 40LD/8SPAN PERC 4e/Di

This gets the details of all the adapters installed