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Obsolete Releases => SME Server 7.x => Topic started by: Bluephoton on February 24, 2008, 08:42:31 AM

Title: NOOB question about Raid
Post by: Bluephoton on February 24, 2008, 08:42:31 AM
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?
Title: Re: NOOB question about Raid
Post by: raem on February 24, 2008, 09:00:58 AM
Bluephoton

Quote
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

Quote
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"
Title: Re: NOOB question about Raid
Post by: Bluephoton on February 24, 2008, 09:31:57 AM
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.
Title: Re: NOOB question about Raid
Post by: p-jones on February 24, 2008, 10:58:48 AM
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.
Title: Re: NOOB question about Raid
Post by: Bluephoton on February 25, 2008, 03:56:36 AM
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?
Title: Re: NOOB question about Raid
Post by: raem on February 25, 2008, 06:51:42 AM
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).
Title: Re: NOOB question about Raid
Post by: tviles on February 25, 2008, 06:49:58 PM
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.
Title: Re: NOOB question about Raid
Post by: idp_qbn on February 25, 2008, 08:18:40 PM
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

Title: Re: NOOB question about Raid
Post by: raem on February 25, 2008, 10:27:38 PM
tviles

Quote
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
Title: Re: NOOB question about Raid
Post by: Bluephoton on February 26, 2008, 12:07:46 AM
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
Title: Re: NOOB question about Raid
Post by: tviles on February 26, 2008, 03:36:59 AM
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
Title: Re: NOOB question about Raid
Post by: tviles on February 26, 2008, 03:58:51 AM
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.
Title: Re: NOOB question about Raid
Post by: idp_qbn on February 26, 2008, 04:33:56 AM
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
Title: Re: NOOB question about Raid
Post by: Bluephoton on February 26, 2008, 03:44:30 PM
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?
Title: Re: NOOB question about Raid
Post by: idp_qbn on February 26, 2008, 07:58:10 PM
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
Title: Re: NOOB question about Raid
Post by: Bluephoton on February 26, 2008, 09:10:14 PM
Ian

I have my photos backed up on several DVDs.  I even keep a copy at work in case the house burns down.  What if your RAID system goes up in a house fire?  I hope you take more precautions than that.

I would only use a non-RAID system for non critical files.  I can always rip music and movies again if I had to.
Title: Re: NOOB question about Raid
Post by: tviles on February 27, 2008, 02:30:58 AM
Blue login to the root and type in htop. It's task manager SME style!
Title: Re: NOOB question about Raid
Post by: tviles on March 02, 2008, 12:22:46 AM
Ian I want to run ZoneMinder on this SME server. Can you point me in the right direction? I downloaded ZoneMinder-1.23.2.tar.gz
http://www.zoneminder.com/downloads.html

Title: Re: NOOB question about Raid
Post by: Bluephoton on March 02, 2008, 05:33:35 AM
Ray

I got the second 500gb drive and installed it (waited for a full resync and then rebooted) and then did the steps here:

http://wiki.contribs.org/Raid (I see they have changed substantially since I last attempted)

It seemed to work ok and a df -h command showed 456gb but I couldn't map it with my XP box - it just showed no drives on my server in explorer.

I rebooted everything and I still can't see it with explorer even though I could access the console from the xp box no problem. 

Disk redundancy now says:

Only some of the RAID devices devices are clean

Manual intervention may be required.

It looks like md2 is "resync = 30.7%" and its going to take 344 min !

I have the data backed up (and that only took 120 min) so I am just going to start over again with a fresh install on the 2 - 500gb drives.

Just wanted to let you know how it turned out.
Title: Re: NOOB question about Raid
Post by: tviles on March 02, 2008, 10:33:06 PM
Dang so when I get my new used drives from Ebay I get to reload SME?
Dell poweredge with BP board. SCSI drives 80 pin.
Title: Re: NOOB question about Raid
Post by: Bluephoton on March 03, 2008, 12:59:09 AM
That was my experience but maybe I did something wrong.

I reloaded and it works great now - 467GB of storage space.

Title: Re: NOOB question about Raid
Post by: tviles on March 03, 2008, 03:47:30 AM
Sweet, I will just have to load up this server and take it to work and reload it. Still on dial up at the house.
Title: Re: NOOB question about Raid
Post by: tviles on March 03, 2008, 03:53:07 AM
Actually I will probably give up on SME. I want to get my security cameras over to the server which I could do with a Linux program called Zoneminder, but I think we are going to go with a EVDO card out here for faster internet and the software is not going to load on Linux I don't think. I might be wrong but I think we would have to use the program supplied by Sprint/Embarq.