LVM Emergency

gundark · #1 23rd July 2006, 07:20 PM

Hello all,

This constitutes an emergency, at least on my part so I will be doing research but I wanted to post this right away. My hard drive on my laptop has bit the dust, or so I thought. I have been trying for two days to get it to do anything and well right now it is sitting and waiting to be used. The only problem is I have no idea how to mount an LVM partition.
Here is the setup, its a standard fedora 5 partitioning scheme, on a hard drive, in an external bay (dev/sda)(the partition I need is (dev/sda2).
The laptop it is connected to is also a standard fedora 5 partitioning scheme, dev/hda2 being the equivalent partition on this computer.
The big problem I see, they are both called VolGroup00, but I have no idea if that matters.
I would guess I only have a few minutes with the hard drive, at most an hour and I desperatly need my home folder, I would be forever in anyones debt who could help me.

SlowJet · #2 23rd July 2006, 08:00 PM

To mount an LV in a VG
mount /dev/mapper/vgname-lvname /mnt/point

Before mounting the VG must be available.
vgchange -a y

However, the default install used VolGroup00 for the VG name.
So unless you changed it (s/b uniqueue for each install) you can NOT have 2 VG with the same name in the system.

You best course is to boot up with the bad drive and copy the /home data that you need to a CD.
Then boot up with the good drive and
cd /home/you
mkdir olddata
copy the data to /home/you/olddata

then cp files to the right place.

SJ

PeterC · #3 23rd July 2006, 08:14 PM

Hi

Save yourself some time and grief, get Knoppix live CD and some sort of external USB drive (HDD or Pendrive) fire up knoppix use that to mount the HDD and copy across to the external drive.

Be aware your HDD my not be shagged it could be the LVM is faulty. I went through 3 Hard drives last month with pretty much the same errors as you (I have a Dell Latitude PIII 600) I got my /home dir off and did a fresh install.

I hope it all works out for you.

gundark · #4 23rd July 2006, 08:21 PM

I have two thoughts, the hard drive stopped working again so I don't know when I will get another chance to try, could I rename the VolGroup00 on the working computer so that the next time the hard drive works this would be simpler, and would the device mapper pick up on the volume group in the external hard drive when I connect it through USB? To be a pain in the ass can you give me an example of the code I would type to to that?

Now the reason I have to connect it through usb is that the enclosure allows me to turn on the power before connecting data, if I do this the hard drive powers up and after a few minutes spins down and then and only then can be connected to a computer, or all of the ones I have around here lock up.

By the same token would the knoppix cd automatically mount the LVM?

PeterC · #5 23rd July 2006, 08:40 PM

Quote:

Originally Posted by gundark

I have two thoughts, the hard drive stopped working again so I don't know when I will get another chance to try, could I rename the VolGroup00 on the working computer so that the next time the hard drive works this would be simpler, and would the device mapper pick up on the volume group in the external hard drive when I connect it through USB? To be a pain in the ass can you give me an example of the code I would type to to that?

Now the reason I have to connect it through usb is that the enclosure allows me to turn on the power before connecting data, if I do this the hard drive powers up and after a few minutes spins down and then and only then can be connected to a computer, or all of the ones I have around here lock up.

By the same token would the knoppix cd automatically mount the LVM?

Quote:

I have two thoughts, the hard drive stopped working again so I don't know when I will get another chance to try, could I rename the VolGroup00 on the working computer so that the next time the hard drive works this would be simpler, and would the device mapper pick up on the volume group in the external hard drive when I connect it through USB? To be a pain in the ass can you give me an example of the code I would type to to that?

To be honest I wouldn't know how to do it that way

Quote:

Now the reason I have to connect it through usb is that the enclosure allows me to turn on the power before connecting data, if I do this the hard drive powers up and after a few minutes spins down and then and only then can be connected to a computer, or all of the ones I have around here lock up.

Am I misunderstanding you? Are you booting off this USB drive? I thought this was an internal HDD in your Latitude?

Quote:

By the same token would the knoppix cd automatically mount the LVM?

If this HDD is an external drive connected via USB then any machine should be able to read it when you plug it in (On a Windows box you'll need something like Partion Magic or LTools)

If you boot from it then that's OK too if you have two USB ports, unplug all USB drives fire up Knoppix (it runs in memory) plug in the faulty drive and a good one and hopefully Knoppix will see both thentransfer bad to good.

gundark · #6 23rd July 2006, 09:26 PM

Ok, sorry to clarify
I can't use the bad HDD in any internal form because it for some reason has a short and disables the ide bus, so I have to use it in an external usb case, but it is the old hard drive from my inspiron, I try pluging it into my laptop with a new hard drive and fresh install of fedora 5 and it mounts the boot partition just not the lvm I would assume because they are both labled VolGroup00? But from what I understand any other computer like, windows or knoppix would work as long as I have the right tools?

SlowJet · #7 23rd July 2006, 09:44 PM

Quote:

Originally Posted by PeterC

Hi

Save yourself some time and grief, get Knoppix live CD and some sort of external USB drive (HDD or Pendrive) fire up knoppix use that to mount the HDD and copy across to the external drive.

Be aware your HDD my not be shagged it could be the LVM is faulty. I went through 3 Hard drives last month with pretty much the same errors as you (I have a Dell Latitude PIII 600) I got my /home dir off and did a fresh install.

I hope it all works out for you.

He didn't sya what error the drive was giving.
He later said, Now the drive causes a short in the IDE (how he knows this is questionable.)

Now you are selling soap about LVM damaging 3 hard drives?
I do not belief that is possible.

SJ

gundark · #8 23rd July 2006, 09:49 PM

I know this because when I put the drive in one of the 7 dell c840's I have acess to the drive is not only not regognized but it also disables the cdrom drive so that I can not boot even knoppix, instead the only thing I can boot is a floppy and once its utils are up I can only find the floppy and other devices but no mention of anything connected to that bus, so I am just assuming. However once I follow the vodoo magic solution of pluging it in, in the usb external box, in odd ways, I can finally get it and see it, and get the boot to mount, just not the lvm

PeterC · #9 24th July 2006, 09:59 AM

Quote:

Originally Posted by SlowJet

Now you are selling soap about LVM damaging 3 hard drives?
I do not belief that is possible.
SJ

No, I didn't say that , what I said was the LVM maybe corrupted and in turn reporting that the HDD is faulty when in actual fact it might not be, there are ample examples of this problem if you care to google there are even references to it in this forums archives. I blogged about this on my site www.cannon-linux.co.uk

However in this case the information is sketchy at best having read back through the posts there appears to be a power issue on top of a possible faulty HDD with a complicated boot/mount process.

Seeing as you know all about this I'll withdraw and let you fix it