topic Linux disk replacement in Operating System - Linux

Linux disk replacement

Habib_4 — Thu, 14 Sep 2006 14:53:49 GMT

Hi people,

We have recently replaced a disk on a linux box using version 2.4.21-20.ELsmp GNU/Linux, Red Hat Enterprise Linux AS release 3 (Taroon Update 3)Kernel \r on an \m.
Now, the disk replaced is a mirror of the boot disk and is currently flashing green.

How can I tell if it is synchronising and re-building properly as there is 72GB worth of data on this disk and it needs to work!!!?????

Cheers

Re: Linux disk replacement

George Liu_4 — Thu, 14 Sep 2006 14:59:18 GMT

Is it a Hardware RAID?

Re: Linux disk replacement

Habib_4 — Thu, 14 Sep 2006 15:00:57 GMT

Hi George,

How could I tell if it is?

Re: Linux disk replacement

Ivan Ferreira — Thu, 14 Sep 2006 15:21:09 GMT

If software raid, you should have the status in :

cat /proc/mdstat

If hardware RAID, there are specific tools for checking the status, like Array Configuration Utility for SmartArray Controllers.

Re: Linux disk replacement

Habib_4 — Thu, 14 Sep 2006 15:41:05 GMT

Hi Ivan,

I have tried the cat command and it shows:

Personalities :
read_ahead not set
Event: 0
unused devices:

What does this mean?

Re: Linux disk replacement

Matti_Kurkela — Thu, 14 Sep 2006 17:03:20 GMT

Personalities :
read_ahead not set
Event: 0
unused devices:

It means the list of software RAID personality modules (like [raid0] for striping or [raid1] for mirroring) is empty. Thus, no software RAID is in use.

Apparently you have a hardware RAID in your box. Different manufacturers' RAID solutions have different tools to view their state: on HP Proliant servers, the RAID status is viewable on the System Management Homepage if all the necessary software is installed.

If the "hpacucli" package is installed, you can also find out the state of the drives from the command line.

Some hardware RAID drivers also report their status in pseudo-files located under /proc/scsi or /proc/driver. (The files will appear to have zero size, but when viewed using "cat" or "less", they display dynamically-created content based on the current driver status.)

Re: Linux disk replacement

Jaydeb Chakraborty — Wed, 20 Sep 2006 07:42:54 GMT

Interesting thread.
It is very important to know how the disk is mirrored prior to comment any possible solution. Are you using SAN? LUN might be configured in RAID at Storage side.
Is there any configuration of LVM mirror?

Thanks!