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 . ## p_w_picpath create dd if=/dev/cdrom of=/dvd.iso clone p_w_picpath of cd. can use cp to make p_w_picpath: 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
