Partition and Boot Loader questions

[vuserv]

I’ve got a question about modifying my partitions in preparation for loading additional distros on my system. Rather than take up too much of your time I did as much homework as possible. I’ve read the Linux Partition HOWTO from the linux documentation project and am referencing a couple books. That has cleared up quite a bit. Still, it's only been a couple days that I've done anything much with linux and I'm sure I'm missing a few things along the way.

I currently have OpenSuse 10.3 64 bit installed. I let OpenSuse do my partitioning and out of a 160 GB drive ended up with:

# fdisk -l
 
Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x35173516
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1        4865    39078081    f  W95 Ext'd (LBA)
/dev/sda2            4866       19457   117210240    c  W95 FAT32 (LBA)
/dev/sda5               1         262     2104452   82  Linux swap / Solaris
/dev/sda6             263        2126    14972548+  83  Linux
/dev/sda7            2127        4865    22000986   83  Linux

This system is only meant to learn with for the time being. I’m sure I will break things along the way but assume with multiple OSs I’ll always be able to find an easy way to recover, as long as I learn to get comfortable with Grub.

Please correct me if I’m wrong on my description of my system.

The above translates into the first two GB used for my linux swap disk, sda5. Next, sda6 is 14.2 GB. That’s followed by sda7 being 20.9 GB. These all being logical partitions on sda1, a W95 Extended partition. The remainder, sda2, is a 111.7 GB W95 FAT32 partition.

My questions:

Can someone clarify what’s going on with sda7 please? Right now it appears to be a mirror of my /home from sda6. Obviously that was setup automatically. Regardless of which file I change, a file on sda6 or the same file on sda7, the other changes also. Is this a link, hard or symbolic? I read about the linux filesystem in a couple books but haven’t had the chance to put much of it to use yet. Is this mirrored drive necessary? I’d like to delete it, meaning initially increase sda6 to include the sda7 space, then reduce the size of sda1 by about 15 to 20 GB. Alternatively, can I do away with this mirroring (for lack of better terms) and load another distro there? I’ll get into that question below.

Can more than one distro exist on the same primary drive in different logical partitions? Using the alternative example from the previous paragraph, I’d like to have two 15 to 20 GB logical partitions on each primary partition and use all four primary partitions. Disregarding the total number of distros for a moment, on my first primary partition I’d have a distro in sda6 and another in sda7. Then in GRUB my second distro would have an entry something like:

kernel (hd0,7)/boot/vmlinuz...

even though that will be on the same primary partition as my first – main OS. Is that possible?

When I look at configuring GRUB from within YaST, I see it recommends two options, boot from boot partition or boot from root partition. Does this simply mean either /boot or /root? Any suggestions on why one would be better than the other?

I believe I read in the Linux Partition HOW TO that each primary partition that has multiple logical partitions must be an extended partition. That means they’ll all be ID = f correct?

Are there any suggestions for modifying my partitions? Should I use YaST in OpenSuse 10.3 or should I boot with a CD containing gparted and use that?

That should keep me busy for a little while. Once I get a decent plan sorted out, how many distros I’ll have loaded and where, I’ll work on figuring out the best way to load them.

Thanks in advance,

V

[devils casper]

Hi and Welcome !

/dev/sda6 is / (root) and /dev/sda7 is /home partition. SuSe installer creates 3 partitions by default. /, /home and SWAP.
/home partition is mounted under /. check /etc/fstab file. I would suggest you to check this Tutorial on Linux FileSystem.

You can install as many Linux distros as you like. You have 1 Primary, 1 Extended and 3 Logical Partitions right now and you can create 2 more Primary Partitions and 8 Logical Partitions.

I would suggest you to shrink /dev/sda2 partition and assign a bit more space to /dev/sda1 ( Extended Partition ). Create a few more Logical partitions for new distro installation. You should use Gparted or PartedMagic LiveCD for that.

Installer of new Distro will install its GRUB and detect other installed distros for dual/multiboot setup.

When I look at configuring GRUB from within YaST, I see it recommends two options, boot from boot partition or boot from root partition. Does this simply mean either /boot or /root? Any suggestions on why one would be better than the other?

Post the contents of /boot/grub/menu.lst file here.

[vuserv]

You know, I completely missed that about the filesystem. I've been reading 'Unix Power Tools' and 'A Practical Guide to Linux - Commands, Editors and Shell Programming' but somehow I just never caught that. So my sda7 is my /home, not a copy or mirror of it. Dumb me!

So I need to figure a way to get /home associated with sda6 right? Or the easier way would be to shrink sda7 by 15 GB or so and then make sda8 right on sda1 right?

I will then make two more partitions out of sda2, sda3 and sda4, change all three of those to extended partitions and add two logical partitions to each. Am I thinking along the right path?

# cat /etc/fstab
/dev/disk/by-id/scsi-SATA_FUJITSU_MHY2160_K405T7C2A2R5-part6 /            
       ext3       acl,user_xattr        1 1
/dev/disk/by-id/scsi-SATA_FUJITSU_MHY2160_K405T7C2A2R5-part7 /home        
       ext3       acl,user_xattr        1 2
/dev/disk/by-id/scsi-SATA_FUJITSU_MHY2160_K405T7C2A2R5-part2 /windows/C   
       vfat       users,gid=users,umask=0002,utf8=true 0 0
/dev/disk/by-id/scsi-SATA_FUJITSU_MHY2160_K405T7C2A2R5-part5 swap         
       swap       defaults              0 0
proc                 /proc                proc       defaults             0 0
sysfs                /sys                 sysfs      noauto               0 0
debugfs              /sys/kernel/debug    debugfs    noauto               0 0
usbfs                /proc/bus/usb        usbfs      noauto               0 0
devpts               /dev/pts             devpts     mode=0620,gid=5      0 0

Do people usually mount the partitions of other distros within whatever distro they are booting into? In other words, would I have a sda8 associated with /ubuntu and sda9 associated with /slackware when viewed while running OpenSuse?



Here's my menu.lst

# Modified by YaST2. Last modification on Thu Feb 21 22:44:57 EST 2008
default 0
timeout 8
gfxmenu (hd0,5)/boot/message
##YaST - activate
 
###Don't change this comment - YaST2 identifier: Original name: linux###
title openSUSE 10.3 - 2.6.22.17-0.1
    root (hd0,5)
    kernel /boot/vmlinuz-2.6.22.17-0.1-default
root=/dev/disk/by-id/scsi-SATA_FUJITSU_MHY2160_K405T7C2A2R5-part6
vga=0x314 resume=/dev/sda5 splash=silent showopts
    initrd /boot/initrd-2.6.22.17-0.1-default
 
###Don't change this comment - YaST2 identifier: Original name: failsafe###
title Failsafe -- openSUSE 10.3 - 2.6.22.17-0.1
    root (hd0,5)
    kernel /boot/vmlinuz-2.6.22.17-0.1-default
root=/dev/disk/by-id/scsi-SATA_FUJITSU_MHY2160_K405T7C2A2R5-part6
vga=normal showopts ide=nodma apm=off acpi=off noresume edd=off 3
    initrd /boot/initrd-2.6.22.17-0.1-default

Shukriya

V

[devils casper]

So I need to figure a way to get /home associated with sda6 right? Or the easier way would be to shrink sda7 by 15 GB or so and then make sda8 right on sda1 right?

/home partition is for personal data storage and you can shrink it to whatever size you like. 6GB is enough, imho. Shrink /dev/sda7 and create new partition.

I will then make two more partitions out of sda2, sda3 and sda4, change all three of those to extended partitions and add two logical partitions to each. Am I thinking along the right path?

Its not possible to create more than one partition under normal circumstances. There are a few tricks to create more extended partitions but I wont suggest you to do that because its not possible to share data in that kinda setup.

Your Partition Structure is like this:

---- /dev/sda1 -------------- || -------- /dev/sda2 ---------
--- /dev/sda5, 6, 7 --------- ||

You can shrink /dev/sda2 partition and merge free space in /dev/sda1. Create new Logical Partitions ( /dev/sda8, 9, 10.... ) inside /dev/sda1.


According to Menu.lst file, GRUB Menu should offer two options only. First for regular boot up and other for Failsafe mode. Failsafe is somewhat like recovery mode.


EDIT:

Do people usually mount the partitions of other distros within whatever distro they are booting into? In other words, would I have a sda8 associated with /ubuntu and sda9 associated with /slackware when viewed while running OpenSuse?

You have to mount new partitions manually Or you can edit /etc/fstab of SuSe to mount new partitions automatically at boot up. Any distro that you are going to install will detect all existing partitions and mount those automatically.

[vuserv]

Shouldn't I be able to change a configuration file somewhere to tell the system to mount sda8, sda9... so that I can see them?

In the end you're suggesting all my new distros will be in the primary partition sda1, in their own "isolated" logical partition. Is that right?

If OpenSuse decided to put user data on a separate partition, will other distros do the same? Should I leave a large and a small partition for each distro to meet this need?

You have 1 Primary, 1 Extended and 3 Logical Partitions right now and you can create 2 more Primary Partitions and 8 Logical Partitions.

Its not possible to create more than one partition under normal circumstances. There are a few tricks to create more extended partitions but I wont suggest you to do that because its not possible to share data in that kinda setup.

I realize I'm tainted with Redmond mentality. Can't I delete sda2. Then build part of it again as sda2 - primary/extended, sda3 - primary/extended, - sda4 - primary/extended. Then on each of those I make a couple logical partitions.

I guess it's time to start trying things and when it's all broken, fix it. I might plug in another hard drive in one of my home boxes and try adding a second distro to that one first to see what happens. I can't really hurt anything there.

[devils casper]

Shouldn't I be able to change a configuration file somewhere to tell the system to mount sda8, sda9... so that I can see them?

As I mentioned earlier, you can edit /etc/fstab file to mount all new partitions. First of all, create new partitions. I will post necessary code here.

In the end you're suggesting all my new distros will be in the primary partition sda1, in their own "isolated" logical partition. Is that right?

/dev/sda1 is an Extended Partition and your new distros will be in Logical Partition(s), inside Extended Partition.

If OpenSuse decided to put user data on a separate partition, will other distros do the same? Should I leave a large and a small partition for each distro to meet this need?

Partition structure created by installer depends on distro in question. Ubuntu create two partitions only, / and SWAP. Fedora creates three, /boot, SWAP and / ( LVM ).
Best way is, create only one partition for each new distro and format it in ext3 filesystem. Start installation and select Manual Partitioning. Select new ext3 partition and assign it / mount point. You can share existing SWAP partition in all distro. Installer will detect existing SWAP and use it automatically. 6-8GB disk space is enough for the / partition of each distro.

I have 80GB disk in my test machine and I have installed Windows XP + Command Data Storage Partition + 6 Linux distros in it.

I realize I'm tainted with Redmond mentality. Can't I delete sda2. Then build part of it again as sda2 - primary/extended, sda3 - primary/extended, - sda4 - primary/extended. Then on each of those I make a couple logical partitions.

You are not getting my point here.
Its not possible to create more than one Extended partition.
3 Primary Partitions + 1 Extended Partition + Logical partitions inside Extended Partition.

You can create two more Primary Partitions ( /dev/sda3 and 4 are reserved for that ). I would suggest you to either delete /dev/sda2 partition and create a few more Logical Partitions inside /dev/sda1 Or shrink /dev/sda2 to create free space for /dev/sda1.

[gogalthorp]

You can not create an unlimited number of partitions, the HD rules apply to all OS's it is a matter of how hard drives are manged. You can only have 4 partitions max, But a partition may be an extended type which allows you to define up to 8 logical partitions inside the extended one. You must have one primary, and if I remember right it must be the first one.

Also partitions are at fixed locations on the hard drive unlike files which are managed by a file system. So you must pay attention to start and end blocks.

[devils casper]

You must have one primary, and if I remember right it must be the first one.

Thats only if you want to install Windows OS. Linux doesn't care about partition type. You can create Extended Partition without any Primary Partition.

[vuserv]

Well it's been a long productive day. A lot of time spent not getting anywhere and then some quality time making a few things work.

First I decided to take one of my home boxes and simulate what I'm doing on my laptop. No luck. Every distro I tried, OpenSuse, Fedora, Ubuntu, Slackware and Mandriva failed. A couple failed at a pata_ something or another. I really stuck it out and tried but finally after about 6 hours I gave up.

I then decided to dig into my laptop. I broke out GParted and made sda7 smaller. Next thing I know I've got a bunch of ???????????? in my taskbar/start menu. It cleared itself after a few moments but I still have problems with lost + found. I can't write to it or open it. My users seem to be fine though. I'll tackle that later.

Ubuntu was my first attempt at an install. It didn't cooperate too much. I had made a few extra logical partitions on my newly enlarged primary/extended partition sda1, but Ubuntu wanted to do its own thing. I wanted it to use sda8, my next available partition, for everything except the swap which I wanted it to use the existing swap partition. I told it to use sda8 but then it said it was going to use whatever was my last partition. I went back to GParted and took out all additional partitions except for sda8. Once again Ubuntu wanted to do it's own thing. I told it to use sda8. It decided to use sda8, sda9 and sda3, a new primary partition. I gave up on it.

I then loaded Mandriva, which is where I am now. It did what I expected it to do. It now sits on sda8 using sda5 as a swap. No hassles at all. The only thing I've got to work out, for the sake of learning more so than anything right now, is attempting to get back to my openSuse grub. As I'm sure you all know, once I finish the Mandriva install it wants to use its own grub file. I just edited the file to add the openSuse entries and it all works fine now.

In Mandriva the Ethernet and wifi are working right out of the box with no tweaking. My button still doesn't work to start/stop the wireless connection, but that's something else I can work on.

A question, I tried to load Fedora but got the impression it wants more than one DVD. I saw on the download site there were three. Is there really that much data to use for a Fedora install?

I want to try an install with the source files on my hard disk. Any tips you might have will be welcome. I'm off to work on Slackware.

Thanks again,

V

[devils casper]

A question, I tried to load Fedora but got the impression it wants more than one DVD. I saw on the download site there were three. Is there really that much data to use for a Fedora install?

Fedora's .iso comes in three versions.

1. KDE-LiveCD, around 678MB
2. LiveCD ( Gnome ), around 678MB
3. Fedora DVD having all DEs KDE, Gnome and Xfce.

1st and 2nd are for LiveCDs having install option and 3rd is DVD installer.