On Thu, Aug 21, 2014 at 5:32 PM, GKH xaos@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 If a RAID controller is in the middle, whatever algorithm Linux is using is no longer valid.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.