Topic: NOOB question about Raid

[Bluephoton]

I wanted to set up a file server for use in a home network.  I set up SME on a 60GB drive I had available.  Needing more space I installed a new 500GB drive using the  "Manage disk redundancy" utility.

It now seems that I only have 60GB of server space despite the 500GB drive.  Is that how the raid works you are limited to the smallest drive installed?

If I install a third 500GB drive will I still be limited to 60GB?

I apologize for the noob question but the documentation doesn't explain this well.  Could someone give me a quick rundown of how this works or maybe direct me to a resource?

[raem]

Bluephoton

I only have 60GB of server space despite the 500GB drive.  Is that how the raid works you are limited to the smallest drive installed?

Yes

If I install a third 500GB drive will I still be limited to 60GB?

Yes

To increase the size see
http://wiki.contribs.org/Raid
"Upgrading the Hard Drive Size"

[Bluephoton]

Thanks Ray - I read the referenced material but I am afraid that leads me to another noob question.

How do I issue the commands to increase the drive size?  I boot the server and log in as admin and all I see is the "Server Console".  I don't see any way of issuing commands.  If I exit the server console I just go back to the login prompt.

[p-jones]

Login on the server as root. (same password as admin) else use an SSH client like Putty and login as root from a workstation. That will take you to a console prompt where you can follow Ray's instructions.

[Bluephoton]

I issued these commands but didn't have any luck.  It did not change the size of the drive.

http://wiki.contribs.org/Raid
"Upgrading the Hard Drive Size"

I logged into root and I typed them in as shown below:

   1.  mdadm --grow /dev/md2 --size=max
   2. pvresize /dev/md2
   3. lvresize -l +$(vgdisplay -c main | cut -d: -f16) main/root
   4. ext2online -C0 /dev/main/root

Was I supposed to enter #3 as shown or does it require altering what is in the ( ) brackets to suit the config?

[raem]

Bluephoton

Before issuing those commands, did you follow all the steps in sequence and both drives are now 500Gb drives.
ie
# Shut down and install larger drive in system.
# Boot up and manage raid to add new (larger) drive to system.
# Wait for raid to fully sync.
# Repeat steps 1-3 until all drives in system are upgraded to larger capacity.
# Ensure all drives have been replace with larger drives and array is in sync and redundant!

To start the drives syncing you will need to select the option in the admin console (ie when logged in as admin).

[tviles]

So how do you see the amount of disk space? Sorry I'm really new at this. If I go to a mapped network drive on a Windows pc I can see it there.

[idp_qbn]

tviles,
Use PuTTY (or some other terminal program) to connect to your SME server from another PC. Of course, if you have physical access to the server, just sit at the keyboard and logon directly.

1) Log on as root
2) type the following: df -h (the -h makes the output more "human readable")

You will get something like

Filesystem                            Size  Used Avail Use% Mounted on
/dev/mapper/main-root           293G  186G   92G  67% /
/dev/md1                             99M   13M   81M  14% /boot
none                                   506M     0  506M   0% /dev/shm

The important line for you and me is the "/dev/mapper/main-root" line, which tells you how much space is left for users.

Don't forget to logout.

Cheers
Ian

[raem]

tviles

So how do you see the amount of disk space? Sorry I'm really new at this.

Here's more
http://wiki.contribs.org/Useful_Commands

[Bluephoton]

Thanks for the replys.  I believe I see where my problem is. I miss read Ray's original responce and interpreted his instructions as a way of expanding the size of my existing installation.

After reading the replys and re-reading Rays comments I see he intended me to perform those commands after I install an identical 500gb drive to replace my 60gb drive.  I will do this as soon as I can get to the store and pick up another drive.

If I understand it correctly I believe after my 2 existing drives (1 - 60GB and 1 - 500GB) are fully sinked I can shut down and replace my small drive and then start up and add the new drive through the Console and then allow them to re-sink without data loss (of course I will back up to be safe).

I will then perform the instructions Ray pointed to in his original reply to take advantage of the increased capacity.

Tviles (its nice to see I am not the only one really new at this)
Thats how I see the size of the drive by looking at the properties of the mapped drive in windows explorer - handy to have the second method - thanks Ian

[tviles]

This is what I got. I downloaded Putty. So for the home server setup can raid be turned off?
Dell Poweredge 2400 dual 500 cpu 1 gig ram. 5 old Compaq scsi drives.


[root@tracys-linuxbox ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/main-root
                       23G  5.5G   17G  26% /
/dev/md1               99M   21M   74M  22% /boot
none                  506M     0  506M   0% /dev/shm

[tviles]

More questions. If I throw in a adaptec 2940 into a pci slot and hook up 3 more 68 pin scsi drives will SME see them and use them? Or should I start looking on Ebay for used larger SCSI drives with 80 pins that will fit into the BP board? Uh yea I screwed up and bought some 68 pin drives off Ebay already.

[idp_qbn]

tviles,
Don't turn off RAID. I assume you have RAID5, which is what you get with 5 disks (or 4 or 6....)but you also get a level of redundancy with RAID.
ie you can recover if one of the disks dies. Without RAID, if the disk dies, you lose its contents. So, unless you have some other backup strategy (AND USE IT FREQUENTLY), keep the RAID array.

I would suggest that,if they really are getting old, you replace the disks with newer ones.
Remember, it may only be a home server, but the data will be precious to someone.

Cheers
Ian

[Bluephoton]

I understand why it would not be desirable to turn off the RAID but is it possible to turn it off in SME and how would you do that if you wanted to?

Others experience may be different but in the 15 or so years I have had a home computer (I have 4 desktop systems and 2 laptops running now) I have had 1 drive go bad.  I have a stack of old drives on a shelf that are too small to use and I have tossed out many small ones that still worked.

I can see why in a business or academic setting avoiding the loss of critical data would be worth the expence but in a home system?

[idp_qbn]

Bluephoton,
Just wait until your beloved finds you have just lost all the family photos in a puff of electronic static!
"But it's just a home system" won't get you back into the family bed in a hurry!

Cheers
Ian