adding a device to existing RAID 0

adding a device to existing RAID 0

[jef]

after reading & googling all over the place I'm still uncertain that
what I want to do will work. basically I have a 2 device RAID-0 with
existing data on it.

trogdor:# cat /proc/mdstat
Personalities : [raid0]
md0 : active raid0 sdc1[1] sdb1[0]
      1809352448 blocks 8k chunks
       
unused devices: <none>

What I'd like to do is add a third device to increase the capacity.
According to the man page and numerous examples I've found, you can do
this with:

mdadm --add /dev/md0 /dev/sdd

the catch is that all the examples I've seen were for recovering a
RAID-5 (removing a failed device then adding one). Does anyone know if
this will work without destroying the existing data on a RAID-0? 

Thanks in advance!

solution and OT RAID news-story. (was Re: adding a device to existing RAID 0

[Matthew Elvey]

Solution:
man raidreconf
or
http://sman.informatik.htw-dresden.de/man/ALL/raidreconf.html

Amusing story about RAID:
http://www.smh.com.au/articles/2004/08/02/1091412051791.html?oneclick=true
(no you don't have to register - click "Register later and continue to 
your Article 
<http://www.smh.com.au/articles/2004/08/02/1091412051791.html?oneclick=true>")

Flashing the drive activity light.... (was Re: solution and OT RAID news-story.)

[Tim Small]

This reminds me, I did a short stint at a big computing centre, and I 
seem to remember that one of the support staff there had a utility to 
flash the activity light on a SCSI drive (e.g. as mentioned in the 
linked article - to high-light the drive to be replaced), although I'm 
not completely sure if this was on IRIX, or Linux - I searched around 
the net a couple of months ago for a similar utility, but drew a blank.

Any ideas anyone?

Tim.

Re: Flashing the drive activity light.... (was Re: solution and OT RAID news-story.)

[Matthew Elvey (munged)]

On 8/6/2004 3:17 AM, Tim Small sent forth electrons to convey:

> a utility to flash the activity light on a SCSI drive...
>
> Any ideas anyone?

Well, there are hardware raid devices that will flash the an amber or 
red LED to indicate failure, but that'll be specific to the device.
Flashing the activity light is easy to do with a self-rolled script, no?
#!/bin/sh
while true
do
    dd or copy to cause some access
    sleep 1
done