Can a dual boot system use the same home partition and swap partition?

[oshunluvr]

Re: Can a dual boot system use the same home partition and swap partition?

Note that the "grpid" option is for ext2,3,4 and not other file systems.

[reidun]

Re: Can a dual boot system use the same home partition and swap partition?

Ok, my mind is spinning, so I'm going to have to find some quiet time so I can process all this info, and then decide which route I want to go. Thanks everybody for all the input and instructions!

[oshunluvr]

Re: Can a dual boot system use the same home partition and swap partition?

Yeah - it's a lot of stuff...

I'd start with the easiest choice: share a /home partition, but use different usernames.

Once you've played with ii for awhile - re-visit this thread and decide if you need to make any changes.

[Teunis]

Re: Can a dual boot system use the same home partition and swap partition?

There is a middle way and I've been using it for several years.

I have a very solid install of Hardy 8.04 with KDE3.5 on an ext3 partition.
Then for fun I have an ext4 partition with 10.04 with several testing repositories (that soon will be updated to the next Alpha).

Both have their own /root and /home partition.
The 10.04 partition is very small and it's only used for the hidden configuration files.

The important ones like .mozilla-thunderbird are 'just' links from the corresponding configuration files on the 8.04 /home.
Because I have userID 1000 (first and only user) on both systems there are no conflicts.

So start with a primary install and add a second, on the second bare install you link to the '.important app' from the primary install and then install these applications whereby they automagically take over the settings of the primary.

Oh yeah, the swab is shared, I don't often do hibernation.

[errol]

Re: Can a dual boot system use the same home partition and swap partition?

I came across this thread while pondering the basic question used at the beginning. The answers given solved all the questions I was going to raise, except two. I am starting everything from scratch so I am not limited in the way I can set things up. I have 3 HDD's. Two 160GB. One for Windows (which I need for work ) and one for all the Linux (and other - if ever) OS's. I have a 300GB HDD which will be my "/file partition"|

I want to build a grub2 MBR and chainload all my OS's (when I eventually install them). Where do I install the grub2, and how? Does one have to "make" a MBR? How, Where? Maybe I should just install Kubuntu and then edit and maybe move the grub2 to the first partition? If I use ushunluvr's method (the one I want to use - maybe with a few less partitions) would place grub2 in the swap partition.

The other question is about file sharing. I will eventually have at least a triple boot with one of the boots a windows. Is there a way of having the /file partition configured (formatted) that say my Thunderbird mail would be the same for all OS's. I realize from the above that the actual Thunderbird program would have to be installed in each OS. Will the mail file (XXXXX.default) be visible to the windows Thunderbird? Would the /file folder have to be FAT or NTFS (rather than ext4 which I hoped)?
Errol

[oshunluvr]

Re: Can a dual boot system use the same home partition and swap partition?

re: MBR creation - grub will take care of this when you install it. You will need to install it to the drive you are booting to - usually /dev/sda. You may want to install it to another drive also to make things easier in the event of a drive failure. You can install it to your windows drive if you wish - however I think the best policy is to leave the windows drive alone and boot to a different drive by default. This way you could even upgrade your windows install and not affect your boot-ability. How you do this will depend on your bios abilities.

Just to be clear - the MBR is the first 512 bytes of your drive and you have to have at least one MBR on your system. You can also install grub2 to a partition and then boot to it (this is called chainloading) - but you have to boot from a MBR first. The location grub2 is installed (the MBR) is not the same thing as where grub2 keeps it's files. Your other OS's can be booted directly by grub without chainloading. Chainloading means to boot another boot manager from grub. Grub2 does a pretty fair job of automatically detecting and setting up all your other OS's and those that it misses you can manually configure easier than chainloading to a second grub.

The default behavior is when installing your first OS, grub2 will install itself to the MBR and it's files will be in a subdirectory within your install named /boot/grub. When you install a second OS you may either allow it to also install grub2 (possibly it will not have grub2 available and will instead install grub-legacy) which will overwrite the previous MBR. This is not necessarily bad, but if you allow this to happen you will need to remember which OS was the last one you installed if you need to make a change to grub.

If you opt to not allow each subsequent OS to install grub, you then need to boot your "main" OS (the one you installed grub with in the first place) after each new OS is installed and run "update-grub". This method is somewhat better IMO because you'll always know which set of grub files are the "active" ones.

One final but slightly more work option is to have grub totally on it's own partition. This is not common or standard but has the advantage of being immune to subsequent OS installs mis-reconfiguring and allows you to remove or re-install your "main" OS without losing your ability to boot to any other. What I mean by this is when you install grub2 in the default way - with it's files contained in your OS install - is if you remove or reinstall that main OS you'll also have to re-install grub. The disadvantage to this method is the grub menu requires some manual editing after each subsequent OS install. Not a big deal, but you should be aware of that.

re the other question:
The way I share some data (like thunderbird email and firefox settings) across multiple linux installs is use a /file partition (or drive) like your planning. I leave /home in each install so it's settings and such are uncorrupted by other OS's and then remove the Documents and other similar folders and replace them with links to the /files partition. Thunderbird email is kept in a hidden folder in your /home so you do th same thing as above - remove the hidden folder and replace it with a hidden link to /files/.thunderbird.

As far as adding windows to this sharing of email: You'd have to use an NTFS format and I don't even know if windows and linux versions of thunderbird are file compatible.

Assuming you can share windows and linux emails this way I suggest another method: Anything you want to share between windows and linux you simply leave on your windows drive. Linux can read and write to NTFS if you install the proper packages and you can then link to your windows location.

Example: Windows thunderbird keeps email in C:/Documents and Settings/Username/Thunderbird/blah.

You need only mount the windows drive at boot to lets say /mnt/xp and then link to the correct location which in this example would be "/mnt/xp/Documents and Settings/Username/Thunderbird/blah"

If you're planning on sharing all your data with windows, you might as well use an NTFS partition.

[errol]

Re: Can a dual boot system use the same home partition and swap partition?

Thanks oshunluvr !!!
Your answers clarify everything for me.
I now have a question that I presume that only I can answer but would like to hear opinions. I like the idea of leaving the xxxxx.default Thunderbird mail on the Windows partition and mounting it for use with Linux. I am mainly going to use Linux OS's and the only feature I (think) really need to share is Thunderbird mail. Are there other reasons for formatting the /file partition with NTFS and not ext4, or is it ONLY a matter of choice?

[oshunluvr]

Re: Can a dual boot system use the same home partition and swap partition?

The only reason to use ntfs is to permit windows access. Otherwise, it's really not a good idea - too easily corrupted and fragmented.

Since you're kinda new to linux, you should likely stick with ext3 or ext4 just because they're the most common and therefore well supported. For future use you might want to look at a few other formats - xfs performs better with very large files and I use reiserfs because I've found it to perform better with lots of small files. I have a home server with a couple hundred movies on it that I have in a xfs partition and reiserfs is my desktop choice. I also use RAID of several flavors and lvm. To be fair - I tried ext4 for a bit last year and had a couple problems with it. It was kinda brand new then and I think it's very stable now.

If you want to read about whats coming in the future, do a web search for btrfs. It's in the kernel but not ready for prime time yet. I have been playing with it and it has a ton of potential.

Another idea you could explore is figuring out replacements for your windows software so you can dump it all together!

[errol]

Re: Can a dual boot system use the same home partition and swap partition?

Thank you for all your helpful advice.
Errol