Install over LAN

[Keith Clark]

On 12-10-17 05:01 PM, Liam Proven wrote:
> On 17 October 2012 21:24, Keith Clark <keithclark at waterloosubstop.com> wrote:
>> N.B. what kind of RAID array is it? If it is a firmware or software RAID, it
>> might not work under Ubuntu.
>> --------------------------------------------------
>> RAID is:
>>
>> ATA133 RAID supported by Promise PDC20276 controller
>>
>> I have a CD on hand, old as it may be.  Ubuntu 9.04.
> OK - what OS is the machine running at the moment? Already Ubuntu?
>
> In that case, it will almost certainly still work.
No, I just bought 8 of these machines in various configurations and they 
were wiped clean.

>
> RAID is quite complicated. There are 3 kinds, and the problem is,
> manufacturers lie about which theirs is for marketing purposes:
>
> "Hardware RAID" means a chip and software on a card (or *very*
> occasionally on an expensive, specialist motherboard) which controls
> the disks for itself. This kind of RAID appears to the OS on the
> computer as one big disk; the computer can't "see" the individual
> drives. RAID controllers are *expensive* - as much or more as one of
> the disks, as a guide.
>
> "Software RAID" means that the OS itself combines the disks into a
> RAID volume and the OS does the calculations and so on in software.
> Linux has this built in. Only server versions of Windows and Mac OS X
> can do it; the workstation versions cannot.
>
> The Linux tool for managing software RAIDs is called "mdadm" and the
> devices tend to be called /dev/md0, md1 and so on. (I don't know what
> it stands for; I use 'multi-disk' to remember it, myself.)
>
> "Firmware RAID" (also called "Fake RAID") is sort of in the middle. It
> is basically intended for Windows users who can't use their OS's RAID
> functionality for licencing reasons (i.e. the software vendor is
> screwing them over). It uses special connectors on the motherboard or
> controller card plus some firmware on a chip on the card or
> motherboard plus a special device driver in the OS. Boot with the
> firmware off or no driver installed, the OS sees the individual
> drives, not the RAID volume. Boot with the firmware enabled and the
> device driver loaded and the OS sees the RAID volume.
>
> http://en.wikipedia.org/wiki/RAID#Implementations
>
> Promise usually sell cheap, firmware RAID solutions on cheap (£10-£30
> / $15-$50) cards.
>
> I can't find your PDC20276 on Promise's site, just various downloads
> from a decade ago calling it a FastTrak TX. That's their line of cheap
> desktop EIDE firmware RAID cards. I don't know this, it's just a
> guess, but I'm thinking it's a cheap firmware RAID card. I have 2 or 3
> such generic cards myself - they work fine as extra EIDE channels
> under Linux.
>
> You /can/ use firmware RAID under Linux using a tool called "dmraid"
> (the reverse of mdraid, you see, haha). But unless you need to, don't;
> the software RAID implementation is better. If you have the option,
> disable or ignore the card's BIOS, ignore `dmraid` and use an `mdraid`
> instead. If you use the Alternate CD to install, you can create a
> mirror pair during installation, but not with the graphical LiveCD.
>
I'm pretty sure it is a FastTrack.  I'm just installing Ubuntu now so we 
shall see how things work out.

Thanks a bunch for the detailed explanation on RAID though, greatly 
appreciated.  I've never used server hardware/RAID before so it is all 
new to me.

Thanks,

Keith