Centos 7 install with uefi boot and software raid1. How to password protect grub bootloader in linux ostechnix. Create an 100mb software raid partition on sda and sdb for boot create a software raid partition on sda and sdb for swap. To reinstall the grub configuration for the first instance to the. I get through the initial setup of the, hostname, fully quilified domain name, root password, new userpassword setup, and i get to the partioning and software raid configuration. Our backup machine still using red hat 9 uses a raid. Fixing a few common grub errors broken bootloader and. It allows you to choose which operating system or specific kernel to boot into. If the user does intervene and display the boot menu, the windows. During installation, make sure the boot loader is installed in devsda master. Run the root command in grub specifying the desired boot loader installation location. Even users can also easily alter the current boot entries, they can add new entries, select multiple kernels or even they can modify initrd.
A corrupted grub boot loader makes a centos rhel system unable to boot and transfer the control further to linux. If the system partitions are on a software raid install grub 2 on all disks in the raid. I hope to address those here and provide an endtoend guide for myself and others wishing to do similar activities. I made the two 100mb partitions a single raid 1 device, mounted on boot, and the other two a raid 1 device mounted on. In most cases i dedicated a raid1 array to the host os and have a separate array for storage. I have tried to boot the hard disk in either one of the software raid 1 configured in my machine. If you have chosen to automatically partition your system, you should manually edit your boot partition. What is the correct way to install software raid 1 in centos 6. I have 4x80gb seagate sata hdds connected to a 3ware 9500 raid card in a raid5 config. My experience installing centos 5 and centos 6 is that during the installation phase i configured the raid 1 at that time the installation does give you the choice to do this. All other boot items in bootit ng remain functional.
If no keys are pressed the system will now boot windows by default, instead of centos 6. Apr 01, 2017 this guide addresses how to protect grub bootloader with password in centos. How to recover or rescue corrupted grub boot loader in. The reason is that mdadm is not available when grub starts. When the machine reboots back into rhel, it will have working software raid, however the boot.
How to setup a software raid on centos 5 centos wiki. Grub is the reference implementation of the free software foundations multiboot specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular. All modules are digitally signed for your security. To be simply put, its a boot loader package from the gnu linux project. Also you get a protection layer of protection at physical level. I have a raid 0 setup striping via bios not through software raid. Apr 05, 2005 12 replies with centos3, fedora12 i have been able to put boot on a raid1 partition and have it boot normally. Grub configuration fedora 8 page 2 slack brings the team together, wherever you are how to set up software raid1 on a running system incl. This article will provide an example of how to install and configure arch linux with a software raid or logical volume manager. If the grub boot loader hasnt been installed on your hard disk, you should create the configuration file before installing the boot loader in some distributions, the configuration file is boot grub menu. To configure the centos boot loader to chain load from a different boot loader, you must specify the boot drive manually by clicking the full disk summary and bootloader link from the installation destination screen. Instead, you should make a small 1mb partition on each disk and raid them together and set it as a grub boot partition im not sure of the actual name.
Protect your server by locking grub at boot to avoid any unauthorized access. Solved centos no longer boots after raid1 array rebuild. Oct 26, 2019 the boot configuration when using grub 2 is in the boot grub2 grub. Solved centos raid 1 configuration regarding linux. Grub has also got the support of logical block address. Gnu grub short for gnu grand unified bootloader, commonly referred to as grub is a boot loader package from the gnu project. Sep 19, 2017 how to add entry grub 2 on centos 7 for dual boot loader 1. This article addresses an approach for setting up of software mdraid. Im not aware of support in grub to declare two disks as being in a raid1 array so that grubinstall would automatically write to both. Signifies a device, partition, and file where the first boot loader image can be found, such as hd0,0grubstage1. Grub is the reference implementation of the free software foundations multiboot specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating systems partitions. If you run a system on software raid 1, then you also need to manually duplicate the grub bootloader on both disks. But, like everything else in life, it isnt perfect.
To configure the centos boot loader to chain load from a different boot loader, you must specify the boot drive manually by. How do i install grub on a raid system installation. A corrupted grub boot loader makes a centos rhel system unable to boot and transfer the control further to linux kernel. See boot loader installation x86 for instructions on specifying a boot drive. Grub vs grub2 bootloader learn the main difference.
How to recover or rescue corrupted grub boot loader in centos 7. Create a software raid partition on sda and sdb for. But when it gets to install the grub boot loader part i get the following. You can also refer to it by the etcg file which is a symbolic link. Once you are booted in to rescue mode, select the start shell option. Jul 29, 2012 the next time the system is rebooted, the boot screen will wait 20 seconds before autobooting. If you software fail devsda then the bios will continue to use it to boot the system. What has failed here is that when using a bootable software raid array, you have to manually install the grub boot loader to each drive or else they will not be bootable after a crash. I created two 100mb software raid primary paritions, one on each disk, two 512mb linux. This option only works on systems supported by extlinux. When i install linux mint or ubuntu it fails to install the boot loader or set the boot loader to boot.
Ive found that the grub boot loader is only installed on the first disk. Im trying to setup and install ubuntu on a raid 1 setup. Using grubinstall devsdx is probably how it is intended to be done. Make sure that your grub configuration doesnt hardcode disks like hd0, but instead searches for the boot and root filesystems uuids. However, on running yum update the system hangs at the grub boot loader i presume that. Reinitialize grub the boot loader after all of this i was able to mount my raid drives in rescue mode. The problem is at the end of the installation, it tries to install grub.
Its a manual step that has to be done to make software raid work for boot arrays. The new disk that you used for the replacement probably used to have a filesystem on it and grubsetup is now confused by the metadata that is probably still in there so, just wipe out everything at the beginning of the disk up to the first partition. Once in a blue moon, it may give you some problems. Grub boot loader menu shows two linux boot options.
Mirror your system drive using software raid fedora magazine. How to protect grub bootloader with password on centos 7 and. Raid 0 linux installation fails to install grub unix. Reinstall grub devmd0 may be different for you depending on how you configured your software raid grubinstall devmd0. How to set default boot kernel on linux centos rhel 7. I select manual set and create the paritions and software raid and assign ext 4 and swap.
You can check to see that a boot loader is present with. Hello all, i am trying to setup a raid 1 on my system that has 2 identical ide hard disks. Unlike earlier versions that used lilo as the default boot loader, these did not make the 2nd drive bootable but at least i was fairly confident that if the first drive failed i could use the install cd in rescue mode to fix up the 2nd one and go on. Insert centos mediadvd and boot in rescue mode select. Nov 17, 2012 grub boot loader can be configured dynamically, which means a user has an option to make changes while booting.
Mar 06, 2015 if the system partitions are on a software raid install grub 2 on all disks in the raid. When i perform a software raid 1 or raid 5 installation on a lan server with several hard disks, i wonder if grub already gets installed on each individual mbr, or if i have to do that manually. Software raid1 centos install asterisk freeswitch guides. The only problem with boot on software raid is, that if first disk failseg. If you softwarefail devsda then the bios will continue to use it to boot the system. So now if sda were to fail the system would still be able to boot from. How to add entry grub 2 on centos 7 for dual boot loader 1. The grub bootloader will be configured in such a way that the system will still be able to boot if one of the hard drives fails. This can be useful to repair a grub installation if the boot loader was overwritten or damaged. I unmount the virtual cdrom and reboot the server to complete the installation. Using your centos install media, boot in to rescue mode.
If the two disks are devsda and devsdb, run both grubinstall devsda and grubinstall devsdb. Log in and restore your boot loader from the terminal. Centos 6 wont bootload grub on software raid devmd0. If your server is located in a remote area, the best practice may be to configure this to occur automatically. The boot configuration when using grub 2 is in the bootgrub2g file. Password protect your boot loader so that you get an additional level of security right at the booting time. I booted rhel off disk 1, and started working through the installer. The next time the system is rebooted, the boot screen will wait 20 seconds before autobooting. Grub boot loader can be configured dynamically, which means a user has an option to make changes while booting.
It is also possible to use the grub command to install the boot loader, but not the grub files in boot grub. Aug 11, 2016 when i perform a software raid 1 or raid 5 installation on a lan server with several hard disks, i wonder if grub already gets installed on each individual mbr, or if i have to do that manually. In this article, well be looking into figuring out. Safely boot multiple windows and linux systems on both gpt and mbr disks. Instead of booting up centos, it goes to a grub version 0. By default it tries my first disk, which gives a fatal error. One is on the first hard disk third partition, the other is on the second hard disk third partition.
The command will return the partition file system info eg, ext2. But then, its enough to turn the disk off in bios or plug it off from the machine to get the system back booting. The bootloader helps to see locations like devsda1 etc. Home how to set up software raid1 on a running system incl. But the centos does not boot in only one hard disk after trying with the old hard disk. This partition size is based on the amount of ram and personal preferences. This article will provide an example of how to install and configure arch linux with a software raid or logical volume manager lvm. When i do use software raid, i have made a habit of manually installing grub on the other disks using grubinstall. I then proceed to install centos 6 with the default partitioning and default boot loader installed into the mbr. If the default hdd fails then raid will ask you to boot from a degraded disk.
A boot partition is also necessary for software raid setups. If the grub boot loader hasnt been installed on your hard disk, you should create the configuration file before installing the boot loader in some distributions, the configuration file is bootgrubmenu. Installation of the minimum profile, on a raid 1 for boot, 2x swap on each disk and a raid 1 for. How to add entry grub 2 on centos 7 for dual boot loader.
Insert centos mediadvd and boot in rescue mode select rescue mode during boot select the start shell option chroot with. Its the common and reference implementation of a multiboot linux system. Supports both 64 and 32 bit efi firmware as well as bios. Create or edit the configuration file boot grub grub.
When the machine reboots back into rhel, it will have working software raid, however the boot loader will only be installed on the first disk devhda. Now lets create our raid arrays devmd0, devmd1, and devmd2. Grub 2 can read files directly from lvm and raid devices. How to setup a software raid on centos 5 inetservicescloud. First, you should create or edit the configuration file, boot grub grub. How to set up software raid1 on a running system incl. If the user does intervene and display the boot menu, the windows option is now titled windows and not other. Reinstall grub devmd0 may be different for you depending. Software raid 1 setup on centos using grub boot loader. This guide addresses how to protect grub bootloader with password in centos. Even if one of the disks in the raid array fails, the system can still boot. Replace with options for the linux kernel, such as rootdevvolgroup00logvol00 to specify the device on which the root partition for the system is located. First, you should create or edit the configuration file, bootgrubnf.
Briefly, a boot loader is the first software program that runs when a computer starts. Optionally, do find boot grub stage1 to find which partitions have the required grub files in boot grub. In case your next hdd wont boot then simply install grub to another drive. How to protect grub bootloader with password on centos 7. This article describes how to setup a linux system that can boot directly from a software raid1 device using grub. In trying to set this up, ive encountered several pitfalls and complexities. Replace with an absolute path from the partition specified by the root command. Specifies the disk where the stage 1 boot loader should be installed, such as hd0. Stuck at grub prompt after a default centos 6 installation. The grub boot loader can sometimes be damaged, compromised or deleted in centos due to various issues, such as hardware or software related failures or sometimes can be replaced by other operating systems, in case of dualbooting. Centos 6 wont boot load grub on software raid devmd0 1. I would like to know whether there is waytool to verify that the grub loader are indeed installed on both drives. When the raid array has finished to resync, run again grub to install the loader on the new partition with root hd1,0 and setup hd1. This tells grub to assume sdb is the first disk in the system which it is currently assuming sda is and then copy over the bootloader stage1 into the mbr.
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