Home / server / Questions / 426862
In Process
Deleted
Asked: 2012-09-13 12:03:42 +0800 CST

Storage setup on Ubuntu Server used for running virtual machines with software redundancy

  • 772

I have a server I would like to use explicitly for running virtual machines under Ubuntu Server 12.04. It has plenty of RAM, 64GB and three large identical HDD´s. I would like redundancy through software.

How would you recommend I set it up storage?

linux

1 Answers

  1. Thought process:

    • Software RAID is fast enough, with the added advantage of zero hardware dependency.
    • RAID 1 is faster and more trustworthy than RAID 5.
    • RAID 10 requires an additional drive.
    • Ext4 was picked as it´s popular and has little if any less performance then XFS, JFS et. al.
    • The swap area is located last, in the slowest part of the HDDs. I first thought I would skip swap altogether, but decided it could be nice to have and HDD space is cheap. At the same time, I´ll turn down swapiness and expect very little swapping. Thus making it all right to put last on the HDDs.

    Follow these steps: (Tested in a VM)

    1. Partitioning method: Manual
    2. Select each HDD and create an empty partition on them.
    3. Select the FREE SPACE on each HDD and create a new primary partition taking up the entire disk minus RAM + 1MB (which is left for a swap area), used as a physical volume for RAID with the bootable flag on.
    4. Select the FREE SPACE on each HDD and create a new primary partition taking up the rest of the disk (RAM + 1MB), used as a physical volume for RAID with the bootable flag off.
    5. Configure software RAID
    6. Create an MD device with RAID1 as Software RAID device type. Set the number of active devices for the RAID1 array to 2 and the number of spare devices for the RAID1 array to 1. Select the first two devices of equal size not intended for a swap area as active in the RAID1 array and the last one (of equal size to the first two) as a spare.
    7. Create an MD device with RAID1 as Software RAID device type. Set the number of active devices for the RAID1 array to 2 and the number of spare devices for the RAID1 array to 1. Select the first two devices of equal size intended for a swap area as active in the RAID1 array and the last one (of equal size to the first two) as a spare.
    8. Finish the software RAID configuration.
    9. Select the #1 slot under RAID1 device #0 (you may have a small slot which is marked as unusable, don´t mind it). Use as Ext4 journaling file system with mount point set to / and typical usage set to largefile4.
    10. Select the #1 slot under RAID1 device #1 (you may have a small slot which is marked as unusable, don´t mind it). Use as swap area.
    11. Finish partitioning and write changes to disks.
    12. Answer Yes to the question if you want to boot the system if your RAID becomes degraded.
    • 0