[CentOS] HP ProLiant DL380 G5

Thu Aug 21 23:06:05 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Thu, Aug 21, 2014 at 5:32 PM, GKH <xaos at darksmile.net> wrote:
>
> I hope you realize that your arguments for hardware RAID
> all depend on everything working just right.

Yes, but try a software RAID when you have intermittently bad RAM.
I've been there.  Mirrored disks that were almost, but not quite,
mirrors.

> If something goes wrong with a disk (on HW RAID)
> you can't just simply take out the disk, move it to another
> computer and maybe do some forensics.

You can if that other computer has a matching controller.   If you
expect to do forensics you should have that.  Most people would just
use a backup, though.

> What if I wanted to mix and match? Maybe I don't want my swap
> RAID for performance.

If you want performance, you'll have enough RAM that you won't ever
page swap back in.

> The idea of taking my data (which is controlled by an OSS
> Operating System, Linux) and putting it behind a closed source
> and closed system RAID controller is appalling to me.

Why?  It should all be backed up.

> It comes down to this: Linux knows where and when to position
> the heads of disks in order to max performance. If a
> RAID controller is in the middle, whatever algorithm
> Linux is using is no longer valid.

Really??? I don't think linux has ever known or cared much about disk
geometry and most disks lie about it anyway.

> The RAID controller
> is the one who makes the I/O decisions.
>
> Sorry, this is not something I want to live with.

I think you haven't actually measured any performance.

-- 
   Les Mikesell
     lesmikesell at gmail.com