RAID server check (RH3)

hard raid VS soft raid :

there is no much merit in build soft raid on production enviroment

it is very rare for enterprise to use soft raid. it will cosumet cpu resource.

softraid is base on partitions.

command> mdadm

OS /boot should not put in raid devices.

step:

1. create partition of type0xfd (Linux RAID Autedetect)

2.

## getting MRB from sda

dd if=/dev/sda of=/mbr bs=1 count=446

#file /mbr

## move /mbr to second drive
dd if=/mbr of=/dev/sdb bs=1 count=446

#dd is base on block .
## image create
dd if=/dev/cdrom of=/dvd.iso  clone image of cd.
can use cp to make image: cp /dev/cdrom /dvd.iso
## full clone of hard disk
dd if=/dev/sda of=/dev/sdb  

# dmideco |more

Handle 0x0000
        DMI type 0, 19 bytes.
        BIOS Information
                Vendor: IBM
                Version: -[GRE155AUS-1.14]-
                Release Date: 10/26/2004
                Address: 0xF0A80
                Runtime Size: 62848 bytes
                ROM Size: 4096 kB
                Characteristics:
                        PCI is supported
                        BIOS is upgradeable
                        BIOS shadowing is allowed
                        Boot from CD is supported
                        Selectable boot is supported
                        Japanese floppy for NEC 9800 1.2 MB is supported (int 13
h)
                        Japanese floppy for Toshiba 1.2 MB is supported (int 13h

 5.25"/360 KB floppy services are supported (int 13h)
                        5.25"/1.2 MB floppy services are supported (int 13h)
                        3.5"/720 KB floppy services are supported (int 13h)
                        3.5"/2.88 MB floppy services are supported (int 13h)
                        Print screen service is supported (int 5h)
                        8042 keyboard services are supported (int 9h)
                        Serial services are supported (int 14h)
                        Printer services are supported (int 17h)
                        CGA/mono video services are supported (int 10h)
                        ACPI is supported
                        USB legacy is supported
                        I2O boot is supported
                        LS-120 boot is supported
Handle 0x0001
        DMI type 1, 25 bytes.
        System Information
                Manufacturer: IBM
                Product Name: eserver xSeries 235 -[86712AX]-
                Version: Not Specified
                Serial Number: 99C3974
                UUID: 6E6F9A4E-E51D-B211-8484-90F4D0F3FF02
# uname -r  for OS version

# lspci -vt

-+-[05]-+-03.0  IBM ServeRAID Controller
 |      +-07.0  LSI Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI
 |      \-07.1  LSI Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI
 +-[02]-+-01.0  Adaptec AIC-7892A U160/m
 |      \-08.0  Broadcom Corporation NetXtreme BCM5703X Gigabit Ethernet
 \-[00]-+-00.0  Broadcom CMIC-WS Host Bridge (GC-LE chipset)
        +-00.1  Broadcom CMIC-WS Host Bridge (GC-LE chipset)
        +-00.2  Broadcom CMIC-LE
        +-09.0  ATI Technologies Inc Rage XL
        +-0f.0  Broadcom CSB5 South Bridge
        +-0f.1  Broadcom CSB5 IDE Controller
        +-0f.2  Broadcom OSB4/CSB5 OHCI USB Controller
        +-0f.3  Broadcom CSB5 LPC bridge
        +-10.0  Broadcom CIOB-X2 PCI-X I/O Bridge
        +-10.2  Broadcom CIOB-X2 PCI-X I/O Bridge
        +-11.0  Broadcom CIOB-X2 PCI-X I/O Bridge
        \-11.2  Broadcom CIOB-X2 PCI-X I/O Bridge
# cat /proc/scsi/scsi

Attached devices:
Host: scsi3 Channel: 00 Id: 00 Lun: 00
  Vendor: IBM      Model: SERVERAID        Rev: 1.00
  Type:   Direct-Access                    ANSI SCSI revision: 02
Host: scsi3 Channel: 00 Id: 01 Lun: 00
  Vendor: IBM      Model: SERVERAID        Rev: 1.00
  Type:   Direct-Access                    ANSI SCSI revision: 02
Host: scsi3 Channel: 00 Id: 02 Lun: 00
  Vendor: IBM      Model: SERVERAID        Rev: 1.00
  Type:   Direct-Access                    ANSI SCSI revision: 02
Host: scsi3 Channel: 00 Id: 15 Lun: 00
  Vendor: IBM      Model: SERVERAID        Rev: 1.00
  Type:   Processor                        ANSI SCSI revision: 02
Host: scsi3 Channel: 01 Id: 09 Lun: 00
  Vendor: IBM      Model: 25P3471a S320  2 Rev: 1
  Type:   Processor                        ANSI SCSI revision: 02
Host: scsi3 Channel: 02 Id: 08 Lun: 00
  Vendor: IBM      Model: 32P0042a S320  1 Rev: 1
  Type:   Processor                        ANSI SCSI revision: 02
 # dmesg|grep -i attach
Attached scsi disk sda at scsi3, channel 0, id 0, lun 0
Attached scsi disk sdb at scsi3, channel 0, id 1, lun 0
Attached scsi disk sdc at scsi3, channel 0, id 2, lun 0
Attached scsi generic sg3 at scsi3, channel 0, id 15, lun 0,  type 3
Attached scsi generic sg4 at scsi3, channel 1, id 9, lun 0,  type 3
Attached scsi generic sg5 at scsi3, channel 2, id 8, lun 0,  type 3
# df

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda5              1945124    643612   1202704  35% /
/dev/sda1               147186     81038     58549  59% /boot
/dev/sda7               976468    181668    745196  20% /home
none                   1282872         0   1282872   0% /dev/shm
/dev/sda6               976468     27876    898988   4% /tmp
/dev/sda2              8938540   3262376   5222108  39% /usr
/dev/sda3              1945156   1787384     58960  97% /var
/dev/sdb1            228386892  15414032 201371412   8% /home/bcs/bcs
/dev/sdc1            141120020  42613492  91338036  32% /home/bcs/users_back
/dev/sdb2             53851168     32828  51082800   1% /home/bcs/users