mdraid messages at start-up

evoweiss · Posted: Mon Jul 04, 2011 4:09 pm Post subject: mdraid messages at start-up

Hi all,

When I boot up my work computer I get some message about mdraid. Unfortunately, it just whizzes by way to quickly for me to write down what it is saying. Could somebody tell me how to capture that information into a file or otherwise get it down before it goes? I am using openrc at present and would like to debug this. Also, how can I tell if there are problems with my raid? Nothing seems amiss when I type cat /proc/mdstat.

Best,

Alex

danomac · Posted: Mon Jul 04, 2011 4:52 pm Post subject:

Could you not enable boot logging? I remember reading about that when I upgraded a few machines to openrc.

Voorhees51 · Guru Joined: 05 Nov 2003 Posts: 358

you could try dmesg to get the info

dmesg|less

or pipe output to a file to review
dmesg > tmp_file.log

the messages might just be about the superblocks not being version 0.9
- it relates to the kernel being able to auto mount that superblock version

I just ignore the message

my arrays are ver 1.2 superblocks and I just have them defined in /etc/mdadm.conf and they mount fine with no issues at all

mdadm --detail /dev/mdX -- it will give you more detailed info on the array
- I think syntax is correct, check man page to be sure

One bit of advise I would give is to get the drive info for each disc in the array, specifically the serial number
- keep it in a file and up to date for the discs in the arrays

hdparm -I /dev/<device_name> ... eg hdparm -I /dev/sda

This helps if you have a disc failure in the array, you know exactly which one needs replaced
- you might want to notate where the drives are in the case as well by SN, makes it easier to know where it is and not have to pull them one at a time to check

There are also options for mdadm to monitor the array and notify you by email or other alert to a failed drive
- it works great, mines setup to go to an email address as well as txt message to phone

evoweiss · Posted: Mon Jul 04, 2011 6:22 pm Post subject:

Hi,

Thanks for all the good advice. It looks like the problem is that the system is looking for LVM and I have no logical volumes because I don't use LVM. How do I get it to stop probing for this?

hedmo · Veteran Joined: 29 Aug 2009 Posts: 1334 Location: sweden

evoweiss vrote:

How do I get it to stop probing for this?

mybox ~ # rc-update del lvm boot
* service lvm removed from runlevel boot
mybox ~ #

evoweiss vrote:

I get some message about mdraid.

i have a message at boot that mdraid can not find any configuration but make it auto..... or some thing like that.
i have not had a problem with that.but if i put a new single hdd in my box,mdraid will put it in raid so mdstat tells me
that i have a broken raid set.