[H-GEN] Debian and booting off a RAID mirror partition

[Ben Fowler]

Hi,

On 21 Jun 2012, at 22:34, Ben Martin wrote:

> Hi,
>  You don't stipulate which software RAID you are using. For the parity
> stuff you might like to tell the filesystem the chunk size you have
> chosen so it can stripe its data efficiently. I'd use bonnie++ and
> iozone instead of just copying a few files around so that the machine
> can be optimized for the workload you want (eg, do smaller files
> matter).

I should've been clearer.

I have 4 x 2 TB drives, in hotswappable cradles.

I run software RAID across all drives. For the boot partition, I have a small partition which I had hoped to put RAID 1 (although because of Debian's version of grub being buggy, I couldn't get the boot loader installed).  The root partition and the 'storage' partitions each run RAID 5, spanning all drives.  The partition maps on all drives are identical. I'm running LVM over them, in case I need to grow the filesystems in a pinch.

Thanks for the ideas for the load testing tools.

> 
> Some idea of performance numbers, though my purdee gnuplots have been
> removed from the article it would seem:
> https://www.linux.com/news/hardware/servers/8222-benchmarking-hardware-raid-vs-linux-kernel-software-raid
> 
> Some other numbers to see if you are where you should be:
> https://raid.wiki.kernel.org/index.php/Performance
> 
> Some NAS reviews are also useful for comparison as they just run Linux
> soft raids under the covers and have 4-5 disks on a 1-2ghz ARM chip.
> 

I would have to get back to you on the current performance numbers, as I would need to collect the data first.  I'm happy to discuss what I learn once I know more.

It all does seem like a lot of hassle, and to be honest, unlike ten years ago, when I was right into all this Debian neckbeard-ery (and I was too poor to afford decent hardware!), I'm a bit beyond blowing weekends on getting everything on my home server. However, to have a setup where I have a reasonable amount of control, there really isn't any alternative.

Maybe I should do a proper writeup of my server build at some point.

Cheers, Ben.