Disk sda contains BIOS RAID metadata, but is not part of any recognized BIOS RAID sets. Ignoring disk sda

When install linux, system show "Disk sda contains BIOS RAID metadata, but is not part of any recognized BIOS RAID sets. Ignoring disk sda"

This may cause by this disk have create RAID array by other RAID card.

Try:
# parted
(parted) # parted /dev/sdb --script mklabel gpt
y
q
# parted /dev/sdb --script -- mkpart primary 0 -1
Warning: The resulting partition is not properly aligned for best performance.
# parted /dev/sdb --script print
Model: ATA TOSHIBA MK1002TS (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
#Ctrl+alt+del


Reinstall OS again.

Install RHEL with RAID driver

Install RHEL with RAID driver


RHEL 6 series

The boot option should be "linux dd blacklist=ahci nodmraid".



RHEL 7 series
linux dd modprobe.blacklist=ahci
--------------------------------------------------------------------------
Make a USB DUD key:
       1). Insert the USB key into a linux system
       2). Open a terminal
       3). Type “fdisk –l” to find out what device the USB key is (e.g. "/dev/sda”)
       4). Make sure the USB key is unmounted by typing “umount /dev/sdX” where sdX is the device name
       5). Navigate to where the DUD .img file is located
       6). Type “dd if=nameofDUD.img of=/dev/sdX” where nameofDUD.img is the file name of the DUD image and sdX is the
           device name of the USB key

or
linux inst.dd
Put dirver *.iso in USB key.

When meet grub error 17 installing SLES with ESRT2

When meet grub error 17 installing SLES with ESRT2
At F6 page select Yes,
Enter following command(Boot opion)
while giving driver "brokenmodules=ahci,isci"



To use AHCI controller in LSI Raid Mode
- AHCI controller has to be in LSI RAID mode.
- brokenmodules=ahci has to be provided during OS installation.

To use SCU controller in LSI Raid Mode
- SCU controller has to be in LSI RAID mode.
- brokenmodules=isci  has to be provided during OS installation.

To use both controllers in LSI Raid Mode
- brokenmodules=ahci,isci  has to be provided during OS installation.

Note:
If your RAID volume large than 2T, your grub will have issue while installation.

linux Console_Redirection -RHEL 6.x

linux Console_Redirection -RHEL 6.x

步驟一：編輯 /boot/grub/menu.lst   (legacy mode)
                           /boot/efi/EFI/redhat/grub.conf (UEFI mode)
在 title ..... 上方，加上

## Enable serial console
serial --unit=0 --speed=9600 --word=8 --parity=no --stop=1
terminal --timeout=10 serial console

這行前面加上註解

#splashimage=(hd0,1)/boot/grub/splash.xpm.gz

找到實際開機所需的那一行，例如是

title CentOS-4 i386-up (2.6.9-34.0.2.EL)
        root (hd0,1)
        kernel /boot/vmlinuz-2.6.9-34.0.2.EL ro root=LABEL=/1
        initrd /boot/initrd-2.6.9-34.0.2.EL.img

在 kernel 後方加上 console=tty0 console=ttyS0,9600n8

kernel /boot/vmlinuz-2.6.9-34.0.2.EL ro root=LABEL=/1 console=tty0 console=ttyS0,9600n8

步驟二：編輯 /etc/inittab最下方加上這行

# Enable serial console
sc:2345:respawn:/sbin/agetty ttyS0 115200,9600 xterm

步驟三： 系統預設是不予許 root 直接從 serial console 登入，這樣造成管理不是很方便，所以修改一下設定。
編輯 /etc/securetty，最底下加上
ttyS0

若在Redhat 6的系統發生進入OS發生亂碼

那是因為安裝了tboot套件

可將grub.conf做修改

Removing tboot after installation

1) Using grubby add the existing kernel

# ARGS=$(grep "^[[:space:]]*module /vmlinuz-$(uname -r)" /boot/grub/grub.conf | sed -e 's/^.*x86_64 //' | head -n 1)

# grubby --add-kernel=/boot/vmlinuz-$(uname -r) --args="${ARGS}" --initrd=/boot/initramfs-$(uname -r).img --make-default --title "Red Hat Enterprise Linux without tboot ($(uname -r))"

# grep -v ^# /boot/grub/grub.conf 
default=0
timeout=5
serial --unit=0 --speed=115200
terminal --timeout=5 serial console
title Red Hat Enterprise Linux without tboot (2.6.32-358.el6.x86_64
    kernel /vmlinuz-2.6.32-358.el6.x86_64 ro root=/dev/mapper/vg00-root intel_iommu=on rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg00/swap LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg00/root crashkernel=auto crashkernel=auto console=ttyS0,115200 rd_NO_DM
    initrd /initramfs-2.6.32-358.el6.x86_64.img
title Red Hat Enterprise Linux (2.6.32-358.el6.x86_64)
    root (hd0,0)
    kernel /tboot.gz logging=vga,serial,memory
    module /vmlinuz-2.6.32-358.el6.x86_64 ro root=/dev/mapper/vg00-root intel_iommu=on rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg00/swap LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg00/root crashkernel=auto crashkernel=auto console=ttyS0,115200 rd_NO_DM
    module /initramfs-2.6.32-358.el6.x86_64.img

2) Remove the tboot kernel

# grubby --remove-kernel=/boot/tboot.gz

# grep -v ^# /boot/grub/grub.conf 
default=0
timeout=5
serial --unit=0 --speed=115200
terminal --timeout=5 serial console
title Red Hat Enterprise Linux without tboot (2.6.32-358.el6.x86_64
    kernel /vmlinuz-2.6.32-358.el6.x86_64 ro root=/dev/mapper/vg00-root intel_iommu=on rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us rd_LVM_LV=vg00/swap LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg00/root crashkernel=auto crashkernel=auto console=ttyS0,115200 rd_NO_DM
    initrd /initramfs-2.6.32-358.el6.x86_64.img

• Now can remove tboot, as not in use by grub.

How to install RPM ignore conflicts

How to install RPM ignore conflicts


#rpm -Uvh --force ***.rpm

How to check cpu current frequency

How to check cpu current frequency

#cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq


or 

#cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq