topic Re: Mirroring in Operating System - Linux

Mirroring

vinuhcl — Wed, 20 Jun 2007 05:45:05 GMT

dear friends,

WE are using Redhat 2.4.21-37.ELsmp. Please tell me how to check my root disk is mirrored or not (Software mirror and Hardwareware mirror).

Thanks and regards,

Vinu

Re: Mirroring

Hemmetter — Wed, 20 Jun 2007 06:21:45 GMT

Hi Vinu,

If software mirror try:
# cat /proc/mdstat

If hardware-raid/mirror it depends on your hba. See lspci-command

try:
# cat /proc/scsi/scsi
or ( for Mylex)
# cat /proc/rd/c0/current_status
or ( LSI-Megaraid based):
# megarc -LogPhysInfo -a0

rgds
HGH

Re: Mirroring

vinuhcl — Wed, 20 Jun 2007 06:30:06 GMT

Dear Hemetter,

I exicuted cat /proc/mdstat
command and I got the following out put:
Personalities :
read_ahead not set
Event: 0
unused devices:

What out put I can expect from "cat /proc/mdstat"
if mirroring is there??

Regs,
Vinu

Re: Mirroring

Hemmetter — Wed, 20 Jun 2007 06:42:07 GMT

Hi Vinu,

In case of a md-software raid you should find some entries like this:

# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 hda2[0] hdc2[1]
289088 blocks [2/2] [UU]

But since you dont have something like this you do not have a software-raid/mirror.

So check for HW-raid. What HD-controller do you have?

Do the "lspci" command.

rgds
HGH

Re: Mirroring

vinuhcl — Wed, 20 Jun 2007 06:54:03 GMT

Thank u v much

Re: Mirroring

Rob Leadbeater — Wed, 20 Jun 2007 07:01:46 GMT

Hi,

As you're posting in a HP forum you may well be running on a server with a SmartArray controller.

The configurations for these by cat'ing /proc/driver/cciss/cciss*

For example for the first SmartArray controller in a server you could see something like this:

# cat /proc/driver/cciss/cciss0
cciss0: HP Smart Array P400i Controller
Board ID: 0x3235103c
Firmware Version: 2.08
IRQ: 161
Logical drives: 1
Current Q depth: 0
Current # commands on controller: 0
Max Q depth since init: 1
Max # commands on controller since init: 32
Max SG entries since init: 31

cciss/c0d0: 73.37GB RAID 1(1+0)

Hope this helps,

Regards,

Rob