This will be helpful when one hdd fails theres still a working grub. Linux handles raid and syncs the two boot partitions. In testing i have found that you must install grub in two distinct steps. When i do use software raid, i have made a habit of manually installing grub on the other disks using grubinstall. Insert centos mediadvd and boot in rescue mode select. Insert centos mediadvd and boot in rescue mode select rescue mode during boot select the start shell option chroot with. I get through the initial setup of the, hostname, fully quilified domain name, root password, new userpassword setup, and i get to the. 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. Using your centos install media, boot in to rescue mode. But then, its enough to turn the disk off in bios or plug it off from the machine to get the system back booting.
Im not aware of support in grub to declare two disks as being in a raid1 array so. If the system partitions are on a software raid install grub 2 on all disks in the raid. 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. Using grubinstall devsdx is probably how it is intended to be done. Solved centos raid 1 configuration regarding linux. I had installed my server using software raid1, i am referring them.
You can check to see that a boot loader is present with. Hit the esc key to get back to the grub menu, and boot normally. One is on the first hard disk third partition, the other is on the second hard disk third partition. This article describes how to setup a linux system that can boot directly from a software raid 1 device using grub. I dont need home on a separate partition cause this is a storage device, so only admin users, and none should. 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. After having added both disks to the arrays, it was time to update the initrd again. 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. Hello all, i am trying to setup a raid 1 on my system that has 2 identical ide hard disks.
Dec 12, 2012 if youve just installed centos 6 on software raid and it wont boot off devmd0, try the following. Home how to set up software raid1 on a running lvm system incl. There is no need to modify the bootgrubnf as the survived disk is now hd0, here is what. Create an 100mb software raid partition on sda and sdb for boot.
Once you are booted in to rescue mode, select the start shell option. This guide explains how to set up software raid1 on an already running lvm system debian etch. I am attempting to install debian using the software raid raid 1. I have installed ubuntu, debian and centos dozens of times, and each time i get sent to a grub shell not rescue. Customize partitions and remove all partitions, including lvms, for a fresh start. 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.
Software raid1 centos install asterisk freeswitch guides. R410 w software raid always boots to grub shell after linux. If one disk is larger than another, your raid device will be the size of the smallest disk. I have tried to boot the hard disk in either one of the software raid 1 configured in my machine. 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. On systems using the grub2 boot loader amd64, intel 64, and 64bit arm systems with uefi firmware and ibm power systems servers, the file name will be grub. In most cases i dedicated a raid1 array to the host os and have a separate array for storage. Solved centos no longer boots after raid1 array rebuild. There are some tutorials on how to make a raid1 on a running system, but most of them are clearly copypaste work and untested, some of them even manage to forget to copy partitions from running system to software raidwtf. So again i restart and reedit grub menu directives. This wiki describes how to get linux to see the raid as one disk and boot from it in the same way that windows will install on this type of device. 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. Jun 24, 2005 grub install bootgrubstage1 hd1 bootgrubstage2 p bootgrubmenu.
How to mirror swap, boot and root partions in centosrhel 7 using mdadm utility by admin this post makes changes to partitions, so if there is any existing data on any disks being used for this purpose, it should be backed up prior to creating the raid array as per standard best practices. Create a software raid partition on sda and sdb for and fill to maximum allowable size. If you have any trouble getting into the efi system menu, you can also boot into ubuntu from the centos grub menu, reinstall grub with sudo grubinstall devsda, and follow that with sudo updategrub. Even if one of the disks in the raid array fails, the system can still boot. How to mirror swap, boot and root partions in centosrhel 7. On debian this is called a reserved bios boot area. On systems using the grub2 boot loader amd64, intel 64, and 64bit arm systems with uefi firmware and ibm power systems servers, the file name will be g. Setting up a bootable multidevice raid 1 using linux. Im not aware of support in grub to declare two disks as being in a raid 1 array so that grub install would automatically write to both. Posted by curtis k in administration dec, 12 2012 1 comment.
In trying to set this up, ive encountered several pitfalls and complexities. If you softwarefail devsda then the bios will continue to use it to boot the system. I cant help with installing grub now but what i did to get my raid running is i followed this instruction. How to mirror swap, boot and root partions in centosrhel 7 using mdadm utility by admin this post makes changes to partitions, so if there is any existing data on any disks being used for this purpose, it should be backed up prior to creating the. How do i install grub on a raid system installation. Reinstalling grub will set ubuntu first in the boot order and updating will add the new os to the boot menu. How to set up software raid1 on a running lvm system incl. Using your centos install media, boot in to rescue mode 2. How to set up software raid1 on a running system incl.
Grub isnt actually using it as raid 1 when booting i. I hope to address those here and provide an endtoend guide for myself and others wishing to do similar activities. Make sure that your grub configuration doesnt hardcode disks like hd0, but instead searches for the boot and root filesystems uuids. How to setup a software raid on centos 5 inetservices. What is the correct way to install software raid 1 in centos 6. In such a case, the boot partition must be created on a partition outside of the raid array, such as on a separate hard drive. Instead of using the grub shell, i used grub install to install the boot loader on the hard drives. My understanding is that grub1 doesnt know anything about raid and so cant boot off any kind of raid array. If youve just installed centos 6 on software raid and it wont boot off devmd0, try the following. Centos 6 wont bootload grub on software raid devmd0. Hence, i decided to remove the bootgrub2g file and again recreate the file, which had no luck for me. The g has new directives but when i boot and press e on grub menu i get the old command included quiet and rhgb so when i log in in gnome system crash. I am trying to setup a raid 1 on my system that has 2 identical ide hard disks.
So, i thought to assemble the raid volumes, mount the root volumes and fix the grub devices to match what mdadm detail says i had booted into centos server installs dvd rescue system, chose to execute a shell from the installer environment and not to use a root file system. 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. How to add entry grub 2 on centos 7 for dual boot loader. How to recover or rescue corrupted grub boot loader in centos 7. Grub isnt actually using it as raid1 when booting i. So now if sda were to fail the system would still be able to boot from. Software raid 1 setup on centos using grub boot loader. To reinstall the grub configuration for the first instance to the. If grub was already installed on the hard drives from a previous version of centos that was running software raid partitions, the system will boot after installing 5. R410 w software raid always boots to grub shell after.
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 no matter which one. I have my hardwareowned dedicated server hosted in remote datacenter, running centos release 6. 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. I think that there is a ton of older, but still useful dell rack servers out there but centos 8 wont install on them. Create a software raid partition on sda and sdb for and fill to maximum allowable size click the raid button, create a raid device pick the two 100mb partitions, mount point boot, filesystem type ext3, raid1 default raid device should be md0, click ok. This article addresses an approach for setting up of software mdraid raid1 at install time on systems. It looks like currently most os installers insist on putting boot on a non raid partition or the kind of raid1 partition that looks like a non raid partition, even the installers that support raid5 and grub2 im guessing this limitation is a historical relic leftover from grub1. Create a software raid partition on sda and sdb for swap. This article addresses an approach for setting up of software mdraid raid1 at install time on systems without a true hardware raid controller. The grub bootloader will be configured in such a way that the system will still be able to boot.
Ive found that the grub boot loader is only installed on the first disk. Centos 6 wont bootload grub on software raid devmd0 posted by curtis k in administration dec, 12 2012 1 comment if youve just installed centos 6 on software raid and it wont boot off devmd0, try the following. Otherwise grub will respond with filesystem type unknown, partition. That said, linux software raid is more robust and better supported and thus, recommended over fakeraid if you do not need to dual boot with windows.
Its a manual step that has to be done to make software raid work for boot arrays. It is necessary to use an internal hard drive for partition creation with problematic raid cards. But the centos does not boot in only one hard disk after trying with the old hard disk. In the event of a failure you can boot fine off the second disk because it has an identical copy of the original boot partition. Mar 26, 2014 create a software raid partition on sda and sdb for and fill to maximum allowable size click the raid button, create a raid device pick the two 100mb partitions, mount point boot, filesystem type ext3, raid1 default raid device should be md0, click ok. Centos 7 install with uefi boot and software raid1. If you software fail devsda then the bios will continue to use it to boot the system. This partition size is based on the amount of ram and personal preferences. How to setup a software raid on centos 5 centos wiki. The most important tool for setting up raid is mdadm. This article describes how to setup a linux system that can boot directly from a software raid1 device using grub.
This guide explains how to set up software raid1 on an already running centos 5. Server has 6 2tb drives with 2 software raids on them md0 raid 1 for system and swap and md1 raid 5 for data. How to resolve the issue with centos 6 not booting off software raid boot device. The only problem with boot on software raid is, that if first disk failseg.
A boot partition is also necessary for software raid setups. I have an r410 with a sas6ir no dedicated raid card, 4x3tb drives, and it came preinstalled with windows. Booting will only work with boot on nonraid or raid1 partitions. Otherwise grub will respond with filesystem type unknown, partition type 0xfd and refuse to install. Maybe i dont understand the whole issue but finding the centos 8 wont install on dell systems with an h700 hardware raid controller irks me. The raid will be a linux software raid managed by mdadm be sure to have package. When i do use software raid, i have made a habit of manually installing grub on the other disks using grub install. Apr 05, 2005 12 replies with centos3, fedora12 i have been able to put boot on a raid1 partition and have it boot normally. I would like to know whether there is waytool to verify that the grub loader are indeed installed on both drives. Raid1 can be used on two or more disks with zero or more sparedisks. How to mirror swap, boot and root partions in centosrhel. This mode maintains an exact mirror of the information on one disk on the other disks. How to add entry grub 2 on centos 7 for dual boot loader 1. If you have any trouble getting into the efi system menu, you can also boot into ubuntu from the centos grub menu, reinstall grub with sudo grub install devsda, and follow that with sudo update grub.
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