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Topic
  • 6 replies
  • Latest Post - ‏2013-04-05T18:40:14Z by Storix
nasica88
nasica88
24 Posts

Pinned topic How do I protect the boot disk with RAID on PowerLinux ?

‏2013-04-01T08:27:48Z |
 I am new to linux, and I learn that they do not usually protect the boot disk with LVM or SW RAID on x86 linux. 
On AIX, they usually use AIX LVM mirroring to protect the rootvg.
Is there any method to configure RAID protection likewise for the boot disk in PowerLinux ?
Updated on 2013-04-05T18:40:14Z at 2013-04-05T18:40:14Z by Storix
  • JacobFred
    JacobFred
    1 Post

    Re: How do I protect the boot disk with RAID on PowerLinux ?

    ‏2013-04-01T14:17:19Z  
     Have you tried to use the Standalone Diagnostic CD?
    Standalone Diagnostic CD is a bootable CD with a lots of tools for your Power server. One of this tools is a RAID/ARRAY config. by SAS RAID controller.

    Check the Redbook below on page 48.
    http://www.redbooks.ibm.com/redpapers/pdfs/redp4061.pdf

    Download the Standalone Diagnostic CD here:
    http://www-304.ibm.com/support/customercare/sas/f/diags/home.html

    I recommend you configure the array/raid before install the Linux OS.
  • Brian_King
    Brian_King
    21 Posts

    Re: How do I protect the boot disk with RAID on PowerLinux ?

    ‏2013-04-01T14:22:09Z  
    This depends on if you are using VIOS or not. If you are using VIOS, you can use the mirrorios command to use LVM mirroring to protect your root VG on the VIOS. If you are not using VIOS, the instructions below would apply. 
     
    The 7R2 machine supports hardware RAID 1, although the tools and documentation refer to this as RAID 10. If you currently have Linux installed to a single device RAID 0 hardware array, which would be the common scenario if you are using SSDs, you can use iprconfig to perform a RAID level migration to mirror the contents to a second disk and turn the install into a two device RAID 10 array.
     
    If you currently have Linux installed to a JBOD device, which would be the common scenario if you are using HDDs, you have a couple options, depending on the hardware you have available. You could reinstall to a new RAID 10 array (two or more devices). If you only have a total of two disks, you can either reinstall to a single device RAID 0 array, then perform a RAID migration to RAID 10, or you could attempt to copy the data from the existing install using a rescue image to a newly created single device RAID 0 array, then do a RAID level migration, but this would be an advanced procedure I would not recommend unless you are comfortable with it.
     
    For more details on the hardware RAID controller included on the 7R2, you can refer to the following link:
     
     http://pic.dhe.ibm.com/infocenter/powersys/v3r1m5/topic/p7ebk/p7ebkkickoff.htm
  • nasica88
    nasica88
    24 Posts

    Re: How do I protect the boot disk with RAID on PowerLinux ?

    ‏2013-04-02T00:18:37Z  
    • JacobFred
    • ‏2013-04-01T14:17:19Z
     Have you tried to use the Standalone Diagnostic CD?
    Standalone Diagnostic CD is a bootable CD with a lots of tools for your Power server. One of this tools is a RAID/ARRAY config. by SAS RAID controller.

    Check the Redbook below on page 48.
    http://www.redbooks.ibm.com/redpapers/pdfs/redp4061.pdf

    Download the Standalone Diagnostic CD here:
    http://www-304.ibm.com/support/customercare/sas/f/diags/home.html

    I recommend you configure the array/raid before install the Linux OS.
     Wow, this is really an old document... Anyway, I will try the Standalone Diag CD and update the result in this thread.  Thanks.
     
    http://publib.boulder.ibm.com/systems/hardware_docs/pdf/380509.pdf
    Updated on 2013-04-02T00:18:37Z at 2013-04-02T00:18:37Z by nasica88
  • nasica88
    nasica88
    24 Posts

    Re: How do I protect the boot disk with RAID on PowerLinux ?

    ‏2013-04-02T00:22:45Z  
    This depends on if you are using VIOS or not. If you are using VIOS, you can use the mirrorios command to use LVM mirroring to protect your root VG on the VIOS. If you are not using VIOS, the instructions below would apply. 
     
    The 7R2 machine supports hardware RAID 1, although the tools and documentation refer to this as RAID 10. If you currently have Linux installed to a single device RAID 0 hardware array, which would be the common scenario if you are using SSDs, you can use iprconfig to perform a RAID level migration to mirror the contents to a second disk and turn the install into a two device RAID 10 array.
     
    If you currently have Linux installed to a JBOD device, which would be the common scenario if you are using HDDs, you have a couple options, depending on the hardware you have available. You could reinstall to a new RAID 10 array (two or more devices). If you only have a total of two disks, you can either reinstall to a single device RAID 0 array, then perform a RAID migration to RAID 10, or you could attempt to copy the data from the existing install using a rescue image to a newly created single device RAID 0 array, then do a RAID level migration, but this would be an advanced procedure I would not recommend unless you are comfortable with it.
     
    For more details on the hardware RAID controller included on the 7R2, you can refer to the following link:
     
     http://pic.dhe.ibm.com/infocenter/powersys/v3r1m5/topic/p7ebk/p7ebkkickoff.htm
     Yes... the "RAID level migration" surely sounds complicated.  I dare not ask the detailed procedures.   Thanks anyway.
    So, is using SW RAID to protect the OS disk not a feasible option for PowerLinux ?
  • nasica88
    nasica88
    24 Posts

    SAS RAID card works fine with a Standalone Diagnostic CD

    ‏2013-04-05T06:51:55Z  
     I have a SAS RAID card, feature code "EJ0F" (Storage Backplane -- 6 SFF Drives/SATA DVD/RAID/External SAS Port), and I could configure the RAID array with a Standalone Diagnostic CD as you mentioned.  When the machine is booted with a Standalone Diagnostic CD, it gives you a diag menu as you can see in AIX, and in the Task Selection menu, you can select RAID Array Manager menu.
  • Storix
    Storix
    9 Posts

    Re: How do I protect the boot disk with RAID on PowerLinux ?

    ‏2013-04-05T18:40:14Z  
     There are a couple of ways you can do this. SUSE is better at this than Red Hat if I recall correctly.
     
    PowerLinux requires either a PReP boot partition or a vfat partition to boot from. If using PReP, you configure the root filesystem to be on SW Raid, but set up a separate PReP boot partition and /boot partition. Inside the /boot partition there needs to be a /etc directory (seems odd I know) with the yaboot.conf file.
     
    The yaboot boot loader looks inside each partition it can read for an /etc/yaboot.conf file. If it can find in in /boot, then it does not need access to root filesystem at that stage. 
     
    For example: 
    /dev/sda1 - type 41 PReP 
    /dev/sda2 - type 83 /boot 
    /dev/sda3 - type fd SWRAID /dev/md0 
    /dev/sdb1 - type 41 PReP 
    /dev/sdb2 - type 83 /boot 
    /dev/sdb3 - type fd SWRAID /dev/md0 
     
    You can set up to boot from the first disk and dd /dev/sda1,2 to /dev/sdb1,2. Then if the disk fails, you boot from the 2nd disk instead. There is not a way to mirror the entire disk with SWRAID because the yaboot bootloader does not support booting from RAID. If you go this route, you might want to consider mirrored LVM instead of SWRAID. Still have the boot problem (because yaboot cannot boot directly to LVM either), but you lessen the complexity of having LVM on top of RAID.
     
    Good luck.  If the system is already installed, then you can use Storix SBAdmin to back up the system and reinstall using SW RAID or mirrored LVM. You are able to alter the storage configuration at reinstall time.