“That which does not kill us, hurts like hell!”

Mark [1] and I stopped off at Atlantic Internet [2] after a dinner meeting to find one of the techs still there fiddling with his IOpener. [3] We fiddled around with that, then I showed Mark one of the computers a customer I'm doing work for has.

The IOpener is small. The server I showed Mark was not. This is a large machine, dual Pentium III with one gig of RAM (Random Access Memory) (a gigabyte!) and some 30 gigabytes of RAID (Redundant Array of Inexpensive Disks)-5 storage (small these days, I know).

I'm doing some work for this customer and I had noticed that the 30G of storage wasn't mounted on the server. So, as long as I was there, might as well mount the RAID array. Mark, having a RAID array at home, was on hand to help with the consulting.

megaraid: v107 (December 22, 1999)
megaraid: found 0x101e:0x9010:idx 0:bus 0:slot 9:func 0
scsi0 : Found a MegaRAID controller at 0xd810, IRQ: 17
megaraid: [UF80:1.61] detected 1 logical drives
scsi0 : AMI MegaRAID UF80 254 commands 16 targs 1 chans 8 luns
scsi : 1 host.
scsi0: scanning channel 1 for devices.
scsi0: scanning virtual channel for logical drives.
  Vendor: MegaRAID  Model: LD0 RAID5 35000R  Rev: UF80
  Type:   Direct-Access                      ANSI SCSI revision: 02
Detected scsi disk sda at scsi0, channel 1, id 0, lun 0
SCSI device sda: hdwr sector= 512 bytes. Sectors= 71680000 [35000 MB] [35.0
GB]
 sda: sda1 sda2 sda3 <sda5 sda6 sda7>
(scsi1) <ADAPTEC AIC-7890/1 ULTRA2 SCSI HOST ADAPTER> found at PCI 12/0
(scsi1) Wide Channel, SCSI ID=7, 32/255 SCBs
(scsi1) Downloading sequencer code... 385 instructions downloaded
scsi1 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 5.1.23/3.2.4
       <ADAPTEC AIC-7890/1 ULTRA2 SCSI HOST ADAPTER>
scsi : 2 hosts.

From that, it looked like there were two disk controllers. The system was booting from SCSI (Small Computer System Interface), that much was apparent. What wasn't apparent was the location of the RAID system.

The BIOS (Basic Input/Output System) POST (Power On Self Test) also gave the impression of two controllers. We went into the RAID BIOS extention, initialized the RAID controller and drives and then rebooted the system.

Turns out that the megaraid and the Adaptec SCSI controller are one in the same and that the system itself (it runs Linux) was booting off the RAID controller!

It is through our mistakes that we learn.

And it is through grovelling that we retain our customers.

Fortunately, the customer didn't loose any important data (the customer wasn't using it fully at the time), nor did he mind that much (“Next time, please consult with me before you do any irrepairable configuration changes. Okay?”).

That, and I didn't like the way Linux was installed on the box to begin with.

[1] http://www.conman.org/people/myg/

[2] http://www.aibusiness.net/

[3] /boston/2000/04/13.3

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