Ubuntu 8.04 with RAID5 Fresh/New Install
Why software RAID might you ask?
Well our last scenario had a server with fakeRAID
If you prefer to setup your server with fakeRAID or you want to know more about fakeRAID:
https://help.ubuntu.com/community/FakeRaidHowto
Basically its not the hardware RAID we all know and love. it involves activating it in CMOS and loading a driver in your OS to control your RAID. The server had a CD which only allowed RAID0, RAID1 and RAID10 to be done on a Linux OS. therefore we scrapped this idea.
So we got to installing our system as normal.
and we partitioned the RAID5 (explained later) as directed from other forums/posts. After installing the base system Ubuntu needs to load a bootloader (GRUB or LILO). These refused to install and came up with some errors. So we have a server with a base system, but no boot loader. Felt like sitting in a Ferrari with fireproof attire and slick racing tyres but no damn key to start the thing.
Suprisingly ALL of the solutions (beside 2) we went through never told us anything about the boot loader being such a big issue with RAID5...the truth of the matter is RAID5 and GRUB dont work.
So you have to make another RAID1 array that you mount your /boot partition on and everything works hundreds!
Please Note i will not be held accountable for any damage/loss of data. it is your responsibility to back up your shit before you continue with this.
Here's how you go about it....
In our example I will set up RAID on a three-disk machine. I will have a three-partition RAID 1 array for /boot, a three-partition RAID 5 array for /, and a three-partition RAID 5 array for swap.
Once you see the main partition screen, select “Manual partitioning.”
Once you are finished partitioning, you will have a number of partitions on each drive of type "K raid" At the top of the screen you will see an option “Configure software RAID.” Select that option and at the next screen say Yes to write the changes to the partitioning tables of each of the disks, once you are sure each partition is the size you want.
The next step in the process is to create a multidisk (MD) device for each RAID array. In my case I want to create three MD devices, one for my RAID 1 /boot, one for my RAID 5 swap, and one for my RAID 5 /. For each of these MD devices, I select Create MD, then select the RAID level I want; then I choose the number of active and spare devices I want in the array. In my case I won’t have any spare devices, so I will set this option to three active devices for each array and zero spare devices. Finally, I will select which partitions to use in a particular MD device. If you created each partition in the same order on your drives, this will be simple since /dev/sda1, /dev/sdb1, and /dev/sdc1 (in my case) are all part of the same MD device. Repeat this process until you have created all of the MD devices and then select Finish.
What you will notice is that each of your SCSI drives appears as before, but above them are the RAID devices. These devices will be numbered and will display their RAID level as well as the overall size of the RAID device.
The next step is to tell the partitioner how to use each of these new RAID devices. Select the unlabeled partition on the line under each RAID device and hit Enter. From there you can configure the file system, mount point, and other options as if it were an ordinary partition.
Once you are finished, select “Finish partitioning” and write the changes to disk. The installation program will then continue the rest of the install process. Skip ahead to the Software RAID Management section to learn how to use the features of the mdadm package to manage your software RAID.
Taken directly from:
http://www.informit.com/articles/article.aspx?p=1381888&seqNum=2
Thanks to Kyle Rankin and Benjamin Mako Hill for this post!
check their post out if you would like images of the install.
=)
Well our last scenario had a server with fakeRAID
If you prefer to setup your server with fakeRAID or you want to know more about fakeRAID:
https://help.ubuntu.com/community/FakeRaidHowto
Basically its not the hardware RAID we all know and love. it involves activating it in CMOS and loading a driver in your OS to control your RAID. The server had a CD which only allowed RAID0, RAID1 and RAID10 to be done on a Linux OS. therefore we scrapped this idea.
So we got to installing our system as normal.
and we partitioned the RAID5 (explained later) as directed from other forums/posts. After installing the base system Ubuntu needs to load a bootloader (GRUB or LILO). These refused to install and came up with some errors. So we have a server with a base system, but no boot loader. Felt like sitting in a Ferrari with fireproof attire and slick racing tyres but no damn key to start the thing.
Suprisingly ALL of the solutions (beside 2) we went through never told us anything about the boot loader being such a big issue with RAID5...the truth of the matter is RAID5 and GRUB dont work.
So you have to make another RAID1 array that you mount your /boot partition on and everything works hundreds!
Please Note i will not be held accountable for any damage/loss of data. it is your responsibility to back up your shit before you continue with this.
Here's how you go about it....
In our example I will set up RAID on a three-disk machine. I will have a three-partition RAID 1 array for /boot, a three-partition RAID 5 array for /, and a three-partition RAID 5 array for swap.
Once you see the main partition screen, select “Manual partitioning.”
The first step is to partition each of the disks so they have a /boot, /, and swap partition. When you size the partitions, keep in mind that RAID 1 arrays are only as big as one of the partitions, whereas RAID 5 arrays are as big as all of the partitions combined, minus the size of one partition. While it’s not required that each partition be equal in size, the arrays will base everything on the smallest partition, so if you can make each partition in an array the same size, you will have an easier time.
When you get to the partition settings for each new partition, the section where you can choose the file system and mount point, change the “Use as” option so that it says “physical volume for RAID,”Once you are finished partitioning, you will have a number of partitions on each drive of type "K raid" At the top of the screen you will see an option “Configure software RAID.” Select that option and at the next screen say Yes to write the changes to the partitioning tables of each of the disks, once you are sure each partition is the size you want.
The next step in the process is to create a multidisk (MD) device for each RAID array. In my case I want to create three MD devices, one for my RAID 1 /boot, one for my RAID 5 swap, and one for my RAID 5 /. For each of these MD devices, I select Create MD, then select the RAID level I want; then I choose the number of active and spare devices I want in the array. In my case I won’t have any spare devices, so I will set this option to three active devices for each array and zero spare devices. Finally, I will select which partitions to use in a particular MD device. If you created each partition in the same order on your drives, this will be simple since /dev/sda1, /dev/sdb1, and /dev/sdc1 (in my case) are all part of the same MD device. Repeat this process until you have created all of the MD devices and then select Finish.
What you will notice is that each of your SCSI drives appears as before, but above them are the RAID devices. These devices will be numbered and will display their RAID level as well as the overall size of the RAID device.
The next step is to tell the partitioner how to use each of these new RAID devices. Select the unlabeled partition on the line under each RAID device and hit Enter. From there you can configure the file system, mount point, and other options as if it were an ordinary partition.
Once you are finished, select “Finish partitioning” and write the changes to disk. The installation program will then continue the rest of the install process. Skip ahead to the Software RAID Management section to learn how to use the features of the mdadm package to manage your software RAID.
Taken directly from:
http://www.informit.com/articles/article.aspx?p=1381888&seqNum=2
Thanks to Kyle Rankin and Benjamin Mako Hill for this post!
check their post out if you would like images of the install.
=)
Comments