DAE as JBOD - changing sector size to 512 over Fibre Channel? 1

[rhino99]

Hi folks,

Have a DAE connected to a Brocade via db-9 copper gbics. Dual-paths are visible to my Linux host, however ignores them since the drives have 520-byte sector size. I need to change the sector formatting (possibly even firmware on the drives), but am not sure how to proceed.

Debian Linux (2.4.24)
Emulex LightPulse FC SCSI 7.1.14 (

http://www.google.ca/url?sa=U&start=1&q=http://sourceforge.net/projects/lpfcxxxx&e=10053)

TIA,
Rhino

 

[Chacalinc]

take a look to:

http://www.seagate.com/support/kb/disc/faq/low_level_scsi.html

Download "seatools" from:

http://www.seagate.com/support/seatools/

I'm pretty sure that the disk drives are seagate.

Cheers.

 

[rhino99]

Have grabbed Seatools (Enterprise) and am running the following:

./st -B 512 /dev/sg16 (one of the disks). Not much activity on the Brocade and I'm still at 0%.

sh-3.00# ./st -B 512 /dev/sg16

WARNING!!! Changing blocksize will ERASE all data on drive /dev/sg16
Enter Y to change blocksize to 512, any other key to abort - Y
Setting drive /dev/sg16 to blocksize 512 bytes/block


Starting FORMAT of drive /dev/sg16 . . . DO NOT INTERRUPT!!!
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .
FORMAT on drive /dev/sg16 is 0 % complete . . .

Any way to validate if it's working, or could this be a linux host issue ? Is there a boot-disk equivalent to take the OS out of the picture ?

Rhino.

 

[Chacalinc]

be patiente... low levl format is a bit slow, it could take from 1 to several hours depending on the size of your disk drives. What is the size of each disk drive?

Regarding th switch activity: low level format is done by the disk drive not the controller, so what the command does is tell to the disk drive (to the firmware actually): " hey, take your plates and format them to 512 bytes/sector.. tell me when you are done."

Cheers.

 

[rhino99]

Ahh, gotcha. They're 36GB drives. Wasn't sure if I'd be seeing any host activity.

Will let it run !

Rhino.

 

[Chacalinc]

you should see disk activity anyway.

I made a low level format (but in a symmetrix unit) for 18 GBdisk drives in order to change the format from 512 bytes/sector to 520 (for AS/400 use). It tooks 2,5 hours..

Again, go to smoke, drink a coffe, play games, work, whatever you want... but let it run.

Cheers.

 

[rhino99]

Should I expect 0% status to be updated before 100% ?

Still seeing scrolling status, but at 0%.

Gonna grab a coffee

 

[Chacalinc]

by the way, are your disk drives "Seagate"?

 

[rhino99]

Yes, Seagate drives in the EMC carriers.

 

[Chacalinc]

another thing, in your previous post you asked:

Would the disks in the DAE be presented as multiple targets, or a single target with 10 LUNs ? A Fabric client off the Brocade should see these without Quickloop, correct ?

finally, how did you see the disk drives?

 

[rhino99]

From the Brocade name server, I'm seeing 10 disks presenting themselves via 2 ports. Both sides of the DAE are connected to their respective copper gbic.

On the host side, it appears I'm seeing both disks. Not sure if there's a linux-world DMP solution to handle this once I get the disks formatted...

 

[Chacalinc]

I know there is a product for linux in order to do load balancing.. my problem is that I don't remember the name!

 

[Chacalinc]

got it!!

http://support.novell.com/cgi-bin/search/searchtid.cgi?/en/2003/04/multipath.html

http://freshmeat.net/projects/mdadm/

http://www.cse.unsw.edu.au/~neilb/source/mdadm/

 

[rhino99]

Excellent. I'll fight this battle after I get the drives formatted

Still 0%

 

[Chacalinc]

let it be, let it be...

do you see disk activity?

 

[rhino99]

Every so often, the disk will blink (once every 10-15 seconds or so ?)

 

[rhino99]

Not what I'd expect from low-level formatting a drive. Disk doesn't appear to be constantly writing, but I can't be sure.

Status reported by Seatools is still 0%.

 

[Chacalinc]

Sorry, was out.

hmmm. that's rare... disk drive should be blinking as reading serially.. not every 10 or 15 seconds.

I'm investigating at others places. I'll let you know what I get.

Cheers.

 

[rhino99]

Thanks. Still no update, and drives are showing 15-20 second single blinks. (running -B 512 on another drive, same lack of update, and 0%).

 

[rhino99]

Okay... definately have an issue here. Still at 0%

Will check back in the morning.

Anyone know if there are linux Emulex drives on the Knoppix distributions ?

Rhino