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I recently received my first server - it is a HP ProLiant 320e G8. I've installed Debian Wheezy on it. I had to disable the HP Smart Array controller (B120i) because it was creating problems with the installation (I thought I read that Debian wouldn't mix well with it - hence why I disabled it... was that correct?).

I have 2 1TB SATA drives installed. I'm trying to figure out the best way to utilise the drives. The server will be 'living' in another country. So I figure I'd like to 'reduce' the chances of having to rebuild the system. So I was thinking maybe RAID 1 (Debian software RAID) for boot and system files (if that makes sense - I'm an absolute noobie to this stuff... spent days reading bits and pieces on the net). And then RAID 0 for everything else. Does this sound reasonable or just stupid?

If it is reasonable, then I'm also looking for advice on how to partition and mount the drives... I was thinking something like this:

sda0 4GB raid-autodetect bootable
sda1 16GB raid-autodetect
sda2 80GB raid-autodetect
sda3 900GB raid-autodetect

sdb0 4GB raid-autodetect bootable
sdb1 16GB raid-autodetect
sdb2 80GB raid-autodetect
sdb3 900GB raid-autodetect

md0 raid-level=1 ext4 add devices sda0 & sdb0 mount to /boot
md1 raid-level=1 swap add devices sda1 & sdb1 (no mount - do I have to do anything special?)
md2 raid-level=1 ext4 add devices sda2 & sdb2 mount to /
md3 raid-level=0 ext4 add devices sda3 & sdb3 mount to /home or /var???

Sorry for the brain dump. As mentioned, primarily trying to figure out the best way to utilise the drives & reduce probability of having to rebuild system due to drive dying.

BTW - One last question (sorry, I'm sure this is against the rules). I got both drives new. If I start them up at the same time in a RAID 1 configuration, would I expect them to die around the same time?

Thanks for any help - and please forgive my ignorance.

Thanks.

John.

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    Jun 5, 2014 at 6:09

2 Answers 2

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Your server's RAID controller does not support your operating system.

Your options, if you don't want to use software RAID are:

  • Use a supported operating system like Red Hat or CentOS.
  • Install a Smart Array controller that does use a native driver (hpsa).
  • Check compatibility more closely. HP ProLiant "e" series machines are severely crippled in this aspect and ship with a terrible RAID controller with limited support...

See: HP DL380e Linux not seeing drive array for installation

In general, avoid RAID 0. You don't want that. See: What are the different widely used RAID levels and when should I consider them?

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  • Thanks ewwhite. Are you able to comment further on how I could best utilise these drives? Maybe just RAID 1 where I stated and then no RAID on the rest - just mount one partition to /home and another somewhere else? Sorry, I've obviously posted this on the wrong site.
    – John
    Jun 5, 2014 at 6:30
  • @John I would use hardware RAID 1 by purchasing a Smart Array P420 controller. Is that is not an option, I would use Red Hat or CentOS instead of Debian and leverage the existing Dynamic Smart Array controller in hard are RAID 1. I would not recommend software RAID on this setup, especially if sending it abroad.
    – ewwhite
    Jun 5, 2014 at 6:33
  • And you would RAID 1 every partition (i.e., everything)? Thanks for your continued support by the way.
    – John
    Jun 5, 2014 at 6:36
  • @john yes. Also, the disk lifetime will depend on many factors. Heat, vibration, workload, etc. They are unlikely to fail at the same time.
    – ewwhite
    Jun 5, 2014 at 12:05
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Frankly considering RAID 0 for "everything else" does sound stupid.

RAID 0 should only be used for specific cases where you first of all are sure that losing the data will never cost more than a few minutes of anybody's work. And secondly you should only use RAID 0 if you understand the utilization advantages and disadvantages from using it. Some workloads will be faster on RAID 0 others will be faster on RAID 1. If in doubt go with RAID 1 rather than RAID 0.

Based on this reasoning, I'd say RAID 0 is only for experts, and if you have to ask, you do not have the expertise to use RAID 0. But you are still wiser than those who use RAID 0 without asking questions first, and only ask questions once the RAID dies.

If you'd even think about the possibility of saving any data from a RAID 0 after the first disk dies, you shouldn't have been using RAID 0 in the first place.

One might think that RAID 0 is ok to use for /tmp as well as a swap partition. After all, that's data that would be wiped out on a reboot anyway. So why bother with redundancy? But the drawback of using RAID 0 for those is, that a disk failure is likely to put your system in a state where a reboot is needed, and you won't even be able to do a clean shutdown.

For a server in another country, that does not sound reasonable.

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