SCSI RAID Disks

[admin1979]

Hello Experts,

I have newly appointed on a customer site and need to get hold of the unix systems there. Few of the systems are hacing separate disk enclosures and
are said to be configured using hardware RAID configuration. Now in order to get fully aware of crash recovery of these systems I need to know how the

systems are built initially. I am no expert in hardware RAID configurations so need some help in this. Could someone possibly guide me in right direction
as to how I should proceed in getting familiar with these systems, in knowing its structure.
To start with here I am posting few of the relevant outputs. Please let me know if you need any other information.

This DELL PowerEdge server MARS (Linux) has got few local disks and 2 separate disk enclosures which are said to be RAID mirrored.

--------------------------------------------

MARS:~ # lspci | grep RAID
00:08.0 RAID bus controller: LSI Logic / Symbios Logic PowerEdge Expandable RAID Controller 4 (rev 01)

---------------------------------------------------------------------------

MARS:~ # scsiinfo -l
/dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh

--------------------------------------------


MARS:~ # cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: FUJITSU Model: MAN3184MC Rev: 5508
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: FUJITSU Model: MAP3735NC Rev: 5608
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 02 Lun: 00
Vendor: FUJITSU Model: MAP3735NC Rev: 5608
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 03 Lun: 00
Vendor: FUJITSU Model: MAP3735NC Rev: 5608
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 06 Lun: 00
Vendor: DELL Model: 1x4 U2W SCSI BP Rev: 1.30
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: MegaRAID Model: LD 0 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 01 Lun: 00
Vendor: MegaRAID Model: LD 1 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 02 Lun: 00
Vendor: MegaRAID Model: LD 2 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 03 Lun: 00
Vendor: MegaRAID Model: LD 3 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 04 Lun: 00
Vendor: MegaRAID Model: LD 4 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 05 Lun: 00
Vendor: MegaRAID Model: LD 5 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 06 Lun: 00
Vendor: MegaRAID Model: LD 6 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 08 Lun: 00
Vendor: MegaRAID Model: LD 7 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 09 Lun: 00
Vendor: MegaRAID Model: LD 8 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 10 Lun: 00
Vendor: MegaRAID Model: LD 9 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 11 Lun: 00
Vendor: MegaRAID Model: LD10 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 12 Lun: 00
Vendor: MegaRAID Model: LD11 RAID1 69G Rev: 351S
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 00
Vendor: DELL Model: PV22XS Rev: E.16
Type: Processor ANSI SCSI revision: 03
Host: scsi2 Channel: 05 Id: 06 Lun: 00
Vendor: DELL Model: PV22XS Rev: E.16
Type: Processor ANSI SCSI revision: 03

-------------------------------------------

[Steven E. Protter]

Shalom,

I suspect this system has hardware raid.

To see raid configuration you will need to use utilities built into the system itself. That means booting to the console and hitting the right prompt.

SEP

[admin1979]

Yes. It does have MegaRAID hardware RAID controller. And the utility in use is dellmgr.
So what next? How do I make sure if one of the disks fails or so? How do I proceed to recover.

As there are 2 disk enclosures , lets say having 8 disks in each , how the RAID is configured?
Is it like , all the disks in 1 enclsures are out in one RAID level or so or
Kept 1 disk from each disk enclosure and created a RAID 1 for these 2 disks ?

I am confused.