"chain" hard drives together for root partition?

[Gooberlx2]

At my new job we're using a few OpenSuse boxes for some data analysis. The computers came with two 500GB HDDs installed, one HDD1 mounted at / and HDD2 at /data1.

I have a samba share running so people in another department can push the data to our boxes, which is located at /data1/incoming. These people are not the most computer literate individuals in the world...and they always bitch when they have to adjust their routines (like pushing data to a new share).

Without switching to RAID 0 in the bios and reinstalling everything (which is something I will not be able to do as there is very expensive, very specialized software running on these computers), is there a way I could mount both HDDs to / since, inevitably, HDD2 will run out of space?

....soo...basically I'm hoping to accomplish what RAID 0 does (minus the speed benefits), inside of a pre-existing installation.

 

[Crusty]

LVM

 

[Khyron320]

you can use mount --bind to mount a directory into another.

Im not sure it will work since it is a root directory but..
mount --bind /data1 /
do not do this on a production system test it first.

Personally i would mount --bind this way

mkdir /data1/incoming/data2 (assuming they can live with going up 1 lousy folder)
mkdir /data2
mount --bind /data2 /data1/incoming/data2

edit your permissions as you go along.

Please respond back i'd like to know the solution

 

[SleepWalkerX]

Originally posted by: Crusty
LVM

What he said. *hugs his lvm setup*

With OpenSUSE's yast I imagine it wouldn't be entirely too difficult to set this up.

 

[Gooberlx2]

Hmmm..I'll have to look into LVM. Is it something that will be fairly transparent? Or could I potentially completely hose a system? Unfortunately I just don't have any extra systems sitting around on which to test things.

 

[Crusty]

Originally posted by: Gooberlx2
Hmmm..I'll have to look into LVM. Is it something that will be fairly transparent? Or could I potentially completely hose a system? Unfortunately I just don't have any extra systems sitting around on which to test things.

It's completely transparent to the users of the system. It basically creates a meta drive from your physical drives with the ability to add/shrink/reallocate space based on the drives you add/remove from the LVM. Once you get the LVM setup you mount and interact with it just like any other drive.

 

[phisrow]

Originally posted by: Gooberlx2
Hmmm..I'll have to look into LVM. Is it something that will be fairly transparent? Or could I potentially completely hose a system? Unfortunately I just don't have any extra systems sitting around on which to test things.

Just a word of advice: If you cannot reinstall this system, I strongly recommend that you, if at all possible, take disk images of the present system before poking it. Also, if you have a workstation that you are allowed to install stuff on, get a copy of VMware server(free) and test your LVM-foo in a VM first.

 

[xSauronx]

Originally posted by: phisrow

Originally posted by: Gooberlx2
Hmmm..I'll have to look into LVM. Is it something that will be fairly transparent? Or could I potentially completely hose a system? Unfortunately I just don't have any extra systems sitting around on which to test things.

Just a word of advice: If you cannot reinstall this system, I strongly recommend that you, if at all possible, take disk images of the present system before poking it. Also, if you have a workstation that you are allowed to install stuff on, get a copy of VMware server(free) and test your LVM-foo in a VM first.

if the software is so expensive that deamn well ought to have a full backup in place to start with

/ahbutwhoknows

 

[Netopia]

This thread has whetted my appetite for learning more about LVM, Linux Raid w/LVM, and Windows Dynamic Disks.

I know that with Windows, you have to have specialized software to recover data from Dynamic Disks, and that you can't (or couldn't in the past) use tools like Ghost to create images of Dynmaic Disks (or at least not images that actually worked).

What is the situation like with Linux? If I were to create an LVM set and made it a RAID 5 array, are there FOSS tools to image the system? Are there tools to recover data directly if something happens? Or, excluding the last two questions, does one have to blow away the existing LVM/RAID array and recreate/restore from backup?

Joe
whose curiosity is peaked!

 

[Nothinman]

To convert to LVM you'll have to backup and restore, you can't do it in-place. And you'll have a bit of work on your hands because the root device name will change from /dev/sdXY to /dev/mapper/root or whatever you call the volume. It's not too difficult but it's easy to mess up because you'll have to fixup the initramfs.

What is the situation like with Linux? If I were to create an LVM set and made it a RAID 5 array, are there FOSS tools to image the system? Are there tools to recover data directly if something happens? Or, excluding the last two questions, does one have to blow away the existing LVM/RAID array and recreate/restore from backup?

Generally you do it the other way around, RAID the disks and then put LVM on top of that. But in either case you can image them fine, the image will be the full size of the disk since the imager won't know about the RAID or LVM but it should restore and boot fine. It would be much simpler to just boot from a LiveCD and tar up the filesystem. It's a bit more manual but it's safer and you'll understand more about how it all works so you can fix it when it breaks. =)

 

[Gooberlx2]

Originally posted by: xSauronx

Originally posted by: phisrow

Originally posted by: Gooberlx2
Hmmm..I'll have to look into LVM. Is it something that will be fairly transparent? Or could I potentially completely hose a system? Unfortunately I just don't have any extra systems sitting around on which to test things.

Just a word of advice: If you cannot reinstall this system, I strongly recommend that you, if at all possible, take disk images of the present system before poking it. Also, if you have a workstation that you are allowed to install stuff on, get a copy of VMware server(free) and test your LVM-foo in a VM first.

if the software is so expensive that deamn well ought to have a full backup in place to start with

/ahbutwhoknows

LOL, you'd think wouldn't you? Everything here was in place before I arrived (just started beginning of last week). Still, it's a very new medical lab, established by people who are very smart (MDs), but not necessarily big-picture thinkers when it comes to the computer operations. For example, our working data is set to be backed up, but no one is doing a damn thing about the rest of the filesystems. This unbacked up app I mentioned before costs $24K per workstation, plus proprietary hardware and drivers. We have 3 workstations in the lab. These are the sorts of things I hope to improve.