10.10 install: Dmraid doesn't see second disk array on ich10r

[Petithomme]

Hello dear community,

I've googled my problem but I'm not sure I can find an answer in layman's terms...
So here's my noob, simple question, please answer it in semi-noob-friendly terms :D

I've been trying to install ubuntu for a while on my desktop pc. I gave it another go with 10.10 but I always have the same problem:

I've got two raid sets connected to an ich10r chip and they work fine in windows (2 samsung 1to + 2 raptors 75gb).

Upon installation, dmraid only sets up the first raid set (Samsung array) but not the second one (Clean raptors intended for ubuntu). I don't have any other installation option, all my sata connectors are unavailable.
So, is there a manual install solution? Can I force dmraid to mount the second raid set and not the first one?

I think I read somewhere that this was a dmraid bug, but I can't find it anymore.
Help appreciated. Thanks.

[ronparent]

10.10 did fix most of the raid install problems I had in the past. But this is a new one on me. Have you tried using the alternate install cd which reputedly provides better raid support?

[Petithomme]

I tried the alternate cd, but it's exactly the same...the second array is not detected/mounted by dmraid or the installer...

I've generated a report with the intel matrix storage software in case it helps...

[ronparent]

It does sound like a dmraid bug in that it doesn't seem to be able to identify the second array! Dmraid sets up the symbolic links in /dev/mapper and applies the partition names. The naming convention apparently makes no provision for IDing the second array! I would suggest unplugging the first array and installing, but, then the first would probably not be found when you booted to the 2nd. Dmraid documentation is thin in this regard so I am at a loss in what to suggest.

With 10.10 I have found that a second set of symbolic links is created. This appears to be an undocumented feature. They are found by listing /dev/dm-*. They are listed from 0 thru the number of raid partitions ID'ed. You could check if an additional array is listed there - indicated by one number more than could be accounted for on your 1st array. A number is assigned for each the array as a whole, each partition, and any extended partition. I don't know where the developer are headed with this second set of parallel symbolic links but it would be interesting to find out if your second array is identified. Will look for your response.

[Culter]

I have exactly the same problem. It works using 8.04 but not with 10.04 or 10.10. tried about everything for the last 3 days. even tried Mint9. Works with Suse 11.3 though. As soon as I had Suse working o.k (even booting into xp). I tried Ubuntu 10.10 again, still not working. It wants to install on sda (my free drive is sdb) and refers me to the partition manager. Well there isn't one. Looks like I will be stuck with Suse until someone with more expertise than I can sort it out. Had the same problem with 10.04 in April and I just upgraded via the upgrade manager but I want a clean installation. So I am not holding my breath for a solution.
Don't ask me for more details I am not spending any more time on it. I just want an install CD that works just like Suse did or even xp.

[Petithomme]

With 10.10 I have found that a second set of symbolic links is created. This appears to be an undocumented feature. They are found by listing /dev/dm-*. They are listed from 0 thru the number of raid partitions ID'ed. You could check if an additional array is listed there - indicated by one number more than could be accounted for on your 1st array. A number is assigned for each the array as a whole, each partition, and any extended partition.

I have dm-1 and dm-3 in /dev/

Does that help?

Any dmraid command you need me to run? I'm confused by the amount of options offered by dmraid -h ;p

Edit after googling a bit...

dmraid -ay gives interesting results:


/dev/sdh: "sil" and "isw" formats discovered (using isw)!
ERROR: sil: only 2/4 metadata areas found on /dev/sdc, electing...
/dev/sdc: "sil" and "isw" formats discovered (using isw)!
ERROR: isw: wrong number of devices in RAID set "isw_ecacehcbdc_Raptors" [1/2] on /dev/sdc
ERROR: isw: wrong number of devices in RAID set "isw_iaacdfacb_RaptoRaid" [1/2] on /dev/sdh
RAID set "isw_dcijjaeggj_SamsRAID" already active
RAID set "isw_ecacehcbdc_Raptors" was not activated
RAID set "isw_iaacdfacb_RaptoRaid" was not activated
RAID set "isw_dcijjaeggj_SamsRAID1" already active

[ronparent]

Yes, that last was informative. It looks like the raptors got somehow identified as two separate raid sets of one disk each? Also how could one of them have ended up as sdh? Was something else plugged in to displace one of them. You may have to fix in the raid bios. I think if you can link them so that both raptors are picked up as one raid set in the raid bios your problem may be fixed.

I would approach it by:
- Removing the drives from raid in the bios
- Using ubuntu (live or installed) to erase the meta data from those two drives - 'sudo dmraid -rE sdc' and the same for sdh or whatever it appears as when booted
- rejoining the two drive as members of the same raid 0 set in bios

Only this last step might be necessary, except in my own experience existing meta data is not alway rewritten to reflect a changed ID. At any rate, I think that this has been the problem all along and that it must be fixed in the raid bios setup before dmraid can identify the two raptors a one raid set. Let us know how you make out.

[Petithomme]

You were 100% right! I'm typing this from my speedy new Ubuntu 10.10 installation on my Raptubuntu raid array :D

Apparently there were some dmraid leftovers from I don't know where/when. Clearing it solved the problem, with the command you provided!

Before you answered, I tried Opensuse, which recognised the faulty array but couldn't write to it.

Maybe the default graphical installer needs to be able to clear all previous dmraid data? That would simplify things...

Thanks a bunch!

Extra info. if it helps: rebuilding the array in the intel bios didn't do anything. The "disk utility" from the "System" menu helped me find the correct drives in /dev/ and gave me info about dmraid: both discs stated that they were part of a raid array before I cleared the data, rebooted to rebuild the array in bios and then installed ubuntu succesfully.

[ronparent]

Great to hear it worked out. Hope you have fun with your system.