DSM-G600, DNS-3xx and NSA-220 Hack Forum
Unfortunately no one can be told what fun_plug is - you have to see it for yourself.
You are not logged in.
Announcement
IRC Channel #funplug on irc.freenode.org
#1 2008-02-21 13:37:51
- skydreamer
- Member
- From: At the Atlantic Coast
- Registered: 2007-01-06
- Posts: 232
RAID configuration stored in NVRAM?
I bought a second D-link and wanted to move the disks in the old encosure configured as RAID1 to the new DNS-323. To my surprise they appeared as two separate identical volumes in the new enclosure.
This essentialy proves beyond doubt that the disk configuration must be stored in NVRAM- if it was not the RAID array would have been assembled in the second dlink box.
Having configuration in NVRAM might explain sometimes unpredictable behaviour of the RAID arrays. Now the question is- where it could be stored...? And can it be modified to fix broken disk configuration?
Last edited by skydreamer (2008-02-21 13:38:52)
Offline
#2 2008-02-21 13:59:44
- fordem
- Member
- Registered: 2007-01-26
- Posts: 1938
Re: RAID configuration stored in NVRAM?
I don't think it's the actual RAID configuration that is stored in NVRAM, but rather a flag of some sort that indicates there is a RAID array, the unit then determines the actual volume sizes and configuration from the drives.
If you have the time and the drives available try this - create a RAID array using smaller drives and a second RAID array using larger drives - I think you'll find that you can swap the "pairs" of drives back & forth without any problems - I'm not certain if this holds true for anything other than a RAID1 array utilizing the entire drive space.
I did some tests along these lines a few weeks back in response to a question asked by another forum user and that's what I recall happening.
Last edited by fordem (2008-02-21 14:02:37)
Offline
#3 2008-02-21 14:37:55
- skydreamer
- Member
- From: At the Atlantic Coast
- Registered: 2007-01-06
- Posts: 232
Re: RAID configuration stored in NVRAM?
fordem- I would agree with your findings, as the second enclosure was temporarily running separate volumes.
Is there any way to access the nvram (even from console) or is it docummented in the GPL?
Thanks
Offline
#4 2008-02-21 14:41:50
- HaydnH
- Member
- Registered: 2007-09-28
- Posts: 187
Re: RAID configuration stored in NVRAM?
It's stored in the /etc/raidtab file which you can edit by mounting the mtdblocks with "mount -t minix /dev/mtdblock[0|1] /sys/mtd[1|2]" (replacing "[0|1]" with "0" OR "1")... however I wouldn't like to edit it without having a guaranteed way of undoing the changes... there are 2 mtdblocks (0 and 1) - if the reset button replaces 0 with 1 this would count but I haven't looked at what the reset button actually does.
Offline