Re: [gentoo-user] LiveCD installation not recognizing megaraid RAID set

[Carlos <skyclan@gmx.net>]

Ho-Ki Au a écrit :
> I was trying to put gentoo on a dell poweredge 1950 quadcore xeon machine
> with three disks connected to a lsi PERC 5/i raid controller.  In the BIOS
> settings, all three disks were added to the controller for a RAID5 set up.
>  When I boot from LiveCD (2008 version with 2.6.24-r5 kernel) with
> dmraid='-ay' option, it came up not recognizing the RAID set, as I only saw
> "control" under /dev/mapper.  modprobe megaraid was okay, so was modprobe
> raid5.  Under /dev, I only saw sda, but there was no sdb, sdc.  So it looked
> like there was only one disk but the system did not recognize it as a raid
> set.  Booting from LiveCD with dmraid='-ay' doscsi didn't help.  I got the
> same result.  If I did a dmraid -ay in bash, I got "No RAID disks".  Could
> anyone point me to some instructions on how to make Gentoo recognize the
> PERC 5/i RAID controller?
> 
> I tried both 32bit and 64bit gentoo and results were the same.
> 
> lspci showed:
> 02:0e.0 RAID bus controller: Dell PowerEdge Expandable RAID controller 5
> 
> dmesg showed:
> megaraid cmm: 2.20.2.7 (Release Date: Sun Jul 16 00:01:03 EST 2006)
> megaraid: 2.20.5.1 (Release Date: Thu Nov 16 15:32:35 EST 2006)
> megasas: 00.00.03.10-rc5 Thu May 17 10:09:32 PDT 2007
> megasas: 0x1028:0x0015:0x1028:0x1f03: bus 2:slot 14:func 0
> ACPI: PCI Interrupt 0000:02:0e.0[A] -> GSI 78 (level, low) -> IRQ 17
> megasas: FW now in Ready state
> scsi4 : LSI Logic SAS based MegaRAID driver
> scsi 4:0:0:0: Direct-Access     SEAGATE  ST973402SS       S206 PQ: 0 ANSI: 5
> scsi 4:0:1:0: Direct-Access     SEAGATE  ST973402SS       S206 PQ: 0 ANSI: 5
> scsi 4:0:2:0: Direct-Access     SEAGATE  ST973402SS       S206 PQ: 0 ANSI: 5
> QLogic Fibre Channel HBA Driver
> scsi 4:0:8:0: Enclosure         DP       BACKPLANE        1.05 PQ: 0 ANSI: 5
> scsi 4:2:0:0: Direct-Access     DELL     PERC 5/i         1.03 PQ: 0 ANSI: 5
> scsi 4:0:8:0: Attached scsi generic sg1 type 13
> sd 4:2:0:0: [sda] 284164096 512-byte hardware sectors (145492 MB)
> sd 4:2:0:0: [sda] Write Protect is off
> sd 4:2:0:0: [sda] Mode Sense: 1f 00 10 08
> sd 4:2:0:0: [sda] Write cache: disabled, read cache: disabled, supports DPO
> and FUA
> sd 4:2:0:0: [sda] 284164096 512-byte hardware sectors (145492 MB)
> sd 4:2:0:0: [sda] Write Protect is off
> sd 4:2:0:0: [sda] Mode Sense: 1f 00 10 08
> 
> Thanks very much for your help!
> 

Your RAID set is being detected by the LiveCD.  It looks as though you 
have a RAID5 set using 3x72GB drives.  This would be consistent with the 
size of /dev/sda (144GB).  Because it's hardware RAID, operating systems 
don't usually access each individual disk but rather the disk set 
presented by the controller.

As mentioned by Neil, dmraid is for software RAID management.  If you 
want to manage your RAID controller or disk sets from Linux, you'll have 
to find management software capable of doing this.  Try the server 
manufacture's site or the RAID manufacture's web site to see if such 
software exists.

Hope that helps,
Carlos