[WBEL-users] Software raid and User Mode Linux CD burning on WBEL

[Bill Davidsen]

Alex Georgiev wrote:
> Hi all,
> 
> I want to move the company file server from gentoo to WBEL or
> other RHEL recompiled distro.
> 
> The mother board is an old intel 820 desktop board with 512MB ram,
> Pentium III 500MHz. This server provides the following services for 15 
> windows/linux clients:
>     
>     oracle, samba, nfs, cvs, mail (smtp, pop3), dhcp, dns, http   
>     
> the average load is very, very low.
> Except upgrading to WBEL I want to do 2 additional things:
> 
> 1. Setup a network CD burning software under UML
> We are using a separate machine for cd burning with webCDcreator,
> I would like to move the cd burning to the file server, but
> as some times cd burning makes the kernel panic, I think that I should 
> setup
> User Mode Linux on the file server and provide this service under UML, 
> expecting
> that a kernel panic in the UML, will not affect the underlying WBEL file 
> server. I intent to put a CD writer device and a CDROM device on 
> separate channels of the onboard IDE controller.

Two comments on that, (1) I have never header of anyone doing that, and 
(2) I wouldn't bet that hardware issues wouldn't take down the real 
kernel anyway. The issues I've seen are caused by things like starting a 
burn with no CD, data overrun, mounting CD for read while burning. To 
some extent that can be cured by better practices. Do let us know if UML 
cures the problem, I'm looking at UML for a server farm, so I can move 
to a real machine as load grows.

In general it's not an issue, if you have bad media, scrap it! I'm up 
around 100 burns without an issue, and uptime in the three digits since 
an unplanned reboot.
> 
> 
> 2. Setup a software Raid 0 (mirror) with two 200GB disks using an
> additional PCI IDE controller, The one I can found here is:
>     
>     EIO AP-1680 Ultra ATA/133 IDE RAID Controller Card
>     
>     http://www.ivmm.com/eio/products_ap1680.html with chip 
> set             http://siimage.cubik.com/products/sii0680.asp
> 
> This one is a cheap RAID controller, but I intend to use it as a pure
> IDE controller, connect the two disks on separate channels,
> and set up a software mirror, on wich to install WBEL, user data and 
> Oracle.

RAID-1, and I suggest using Promise, which is also cheap and should 
work. Overhead should be low, even with a small system I see virtually 
no CPU used unless it's doing rebuild or similar. Put the drives on 
separate cables (you knew that).
> 
> I shall buy a new 450 Watt power unit for the box.
> 
> I have not used either EIO AP-1680 controller, UML or software raid so far,
> and I will highly appreciate any comments and suggestions.

Avoid the temptation to just roll in a new XXX instead of using the WBEL 
version. If you want to play cutting edge go FCn and enjoy, otherwise 
use the packages from the distribution. The strong point is stability 
rather than cutting edge.

-- 
    -bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
  last possible moment - but no longer"  -me