How to handle large number of disk devices in "arbitrary" order?

[Markus Koeberl]

On Monday 14 November 2011 16:54:24 Carsten Aulbert wrote:
> Hi all
> 
> first of two questions (second will come later in a separate email).
> 
> We have a couple of machines with a largish number of disk drives
> (currently up to 48) plus one or more "flash drives" - could be USB thumb
> drive, SATA disk on module, SSD, whatever. Of course the order in which
> these are detected is not always guaranteed to be the same which makes
> using setup-storage cumbersome and/or impossible to partition/install.
> 
> Let's assume a single server for less complexity. 12 hard disks and one
> SATA disk on module (DOM[1]) which should get the OS.
> 
> Luckily, here the DOM is usually found as /dev/sda and the disks as
> sdb..sdm thus disk1 refers to the correct device. However, in a different
> machine with a different motherboard another DOM/USB device is the last
> one.
> 
> Our idea as a work-around was to create a symlink to the correct device
> using udev, however FAI dies with an INTERNALL ERROR in setup-storage
> (invalid device /dev/os1 along with a stack trace). From what I found this
> is because /dev/os1 does not match the regexps within the Parser.pm around
> line 293).
> 
> What would be the proper way to address this problem in FAI 3.4.8 if any?
> 
> Ideally, I'd like to end up with a system where I can define any kind of
> mapping for the expected devices per class and FAI picks the correct
> ones(TM) to install the system on and/or create a RAID across...
> 
> Anyone with an idea?
> 
> Cheers
> 
> Carsten
> 
> [1] not to be confused with this largish building in FAI-city

what about /dev/disk/by-id and /dev/disk/by-path ?

It seams to be supported by setup-storage:
/* fully qualified device-path or short form, like hda, whereby full 
* path is assumed to be /dev/hda; may contain shell globbing such 
* as /dev/disk/by-id/scsi-* */ 


-- 
Markus Köberl
Graz University of Technology
Signal Processing and Speech Communication Laboratory
E-mail: markus.koeberl at tugraz.at