ClarIIon FC4700 configuration hotspare disk unbound or bound lun

[Tom Geudens]

Hi,
I've got a very specific question with regards to the configuration of a hotspare disk on a ClarIIon FC4700. The reason I'm asking is because I think EMC is telling me .

Ok here goes. In other to define a hotspare you (in my opinion) :
- Define a RAID-group with type hotspare and 1 disk
- Bind a hotspare LUN

This seems pretty straightforward, only the guy from EMC tells me the LUN should NOT be bound. It even gets better. We also have a FC4500 box where this LUN is bound. This guy tells me that that won't work at all (even though the Management tool clearly indicates this to be a hotspare LUN).

Are there people out there with a FC4700 and would one of them be willing to share the definition of their hotspare's with me ?

Thanks in advance,
Tom

[Michael Tully]

Hi Tom,

As you know we have both models. I play the odd game of golf with our EMC techo, so I'll pin him down and beat out a confession. Once I do (Monday my time) I'll post exactly how ours are configured. Hope this helps your cause.

Cheers
~Michel~

[Tom Geudens]

Hi Michael,
As long as you don't really have to hit him over the head with a golf club (about the only thing I can do with such an object :-) ... it would indeed be usefull.

Looking forward to it ...
Regards,
Tom

[Michael Tully]

Hi Tom,

I was tossing up between my driver and my wedge... If he renegs the first time, definitely the wedge.....

avagoodweekend
Michael

[Tom Geudens]

Hi,
Michael ... stop hitting that guy over the head (if he still has a head by now) ... :-)

Seriously, do you (does anyone) have any more news on this ? Only, I took this box into production (where it now already contains 280Gb of data) thinking this was a minor issue ... but I'm not too sure about this now.

Regards,
Tom

[Michael Tully]

Hi Tom,

I haven't forgotten about you, the EMC engineer who I talk with is on holidays this week, so reaching him with driver or wedge has been impossible. Monday, when he's back okay...

[Martha Mueller · Accepted solution]

Tom,

We have both our hot spare's set up with lun's. EMC set up our system that way, so we never had any discussion about this. Can't really shed any light on the subject, but did want to report the way our's was set up.

[Tom Geudens]

Hi,
Martha, thank you for the information. That's exactly what I expected. Michael, if you can verify this for me I'll be a very happy camper and you'll both receive full marks ! After doing that I'm going to use a ... what was it again ... ah yes, a "wedge" (had to look up in a dictionary what this meant in golf) on our local EMC guys.

Regards,
Tom

[Michael Tully]

Hi Tom,

I managed to talk with our EMC engineer.
This is how we have our FC4700's set up.

We have a row of 73Gb disks and one of these is the designated 'hot spare'. Because the 73Gb disks are the largest that we have we use one of these as the 'hot spare'. If say an 18Gb disk fails, the firmware in the unit kicks in and the hot spare 73Gb disk becomes the 18Gb disk that failed.

On our management station the 'hot spare' shows
up as an 'UNOWNED LUN'

UNOWNED LUN
- LUN 222 (oxde; Hot Spare)
Bus 0 Enclosure 2 disk 9

Hope this is what you wanted to know.

Cheers
~Michael~

[Tom Geudens]

Hi Michael,
I'm still not quite clear about it. Ok, here's what I can see in the Navisphere Manager :
FC4700
RAID Group 0x00 (Unbound)
Bus 0 Enclosure 0 Disk 9
RAID Group 0x01 [RAID 5]
Bus 0 Enclosure 0 Disk 1
Bus 0 Enclosure 0 Disk 2
...
LUN 0 RAID-5
LUN 1 RAID-5
...

RAID Group 0x00 should be the Hot Spare (and has been defined as such), but since the LUN is not bound, it does not show up as such. This is the way EMC defined it and tells me it should be ...

FC4500
RAID Group 0x00 [Hot Spare]
Bus 0 Enclosure 0 Disk 9
LUN 12 Hot Spare
Raid Group 0x01 [RAID 5]
Bus 0 Enclosure 0 Disk 1
Bus 0 Enclosure 0 Disk 2
...
LUN 0 RAID-5
LUN 1 RAID-5
...

RAID Group 0x00 should be the Hot Spare (and this shows up because the LUN has been bound).
This is also the way EMC defined it, but now they tell me this is wrong and that this box is unprotected.

Can you clear this out ?
Tom

[Michael Tully]

Hi Tom,

From what mine shows and the info from the EMC
dude, it should be set similar to mine.

HTH
~Michael

+ FC4700
- RAID Groups
Raid Group 0x00 [RAID 5]
Raid Group 0x01 [RAID 5]
Raid Group 0x02 [RAID 5]
Raid Group etc etc
Raid Group 0xde [Hot Spare]
+ SPA
+ SPB
+ Storage Groups
- Unowned LUNS
UNOWNED LUN
- LUN 222 (oxde; Hot Spare)
Bus 0 Enclosure 2 disk 9

Properties:
Current State: Hot spare ready
Disk Type: Disk
Raw Capacity: 71.552GB
Raid Group ID: 0xde
Raid Group Type: Hot Spare
User Sectors: 139172976
User capacity: 71.257GB
Hot Spare Replacing: Inactive

[Tom Geudens]

Hi Michael,
YES ... that was what I was looking for. Both you and Martha have now verified that EMC is telling me .

Can you do just one more test for me ? I'd like the properties of a disk in one of the other RAID groups. The "Hot Spare Replacing" parameter should be "N/A".

Is this the case ?
Regards,
Tom

[Michael Tully]

My pleasure Tom. I'll have a look in the morning when I get to the office.

Cheers
~Michael~

[Michael Tully]

Hi Tom,

I checked a number of my disks, and they are all the same, sample as below:

Properties:

Current State: Enabled
Disk Type: Disk
Raw Capacity: 17.852GB
Raid Group ID: 0x00
Raid Group Type: RAID 5
User Sectors: 34292480
User capacity: 17.558GB
Hot Spare Replacing: N/A

I'm sure that is what you were after....

Cheers
Michael
(Let me know if you want any info, glad to help!

[Tom Geudens]

Hi Michael (goodmorning - wednesday - for me, goodafternoon - tuesday - for you I believe :-),
Yes, that was the info I was after ! Yesterday I bound the "hot spare"-LUN myself and I'm feeling a lot safer now (not to mention the fact I'm going to enjoy writing a very "spicy" mail to our local EMC-guys).

Thanks for your help on this issue !
Regards,
Tom (who is now going to take a week off - long overdue ... by about 3 years :-)

P.S. If YOU need any info, don't hesitate to ask either. There's probably not a lot of "hardcore" Unix stuff I can help you with ... but you never know (and as long as security allows me to be root on some test-servers I can always dedicate those to solve problems :-).