LinuxQuestions.org

LinuxQuestions.org (/questions/)
-   Ubuntu (http://www.linuxquestions.org/questions/ubuntu-63/)
-   -   Dual boot, two HDs. Separate /boot partition advisable? (http://www.linuxquestions.org/questions/ubuntu-63/dual-boot-two-hds-separate-boot-partition-advisable-561351/)

mailforbiz 06-12-2007 10:19 PM

Dual boot, two HDs. Separate /boot partition advisable?
 
Hi

Would like to know if I'm doing this right. I have two discs A & B with Xp on the first disc. There is unpartitioned space on the second one which I'm planning to install Feisty on.

After researching a bit, this is the partition map I came up with. I know this is somewhat subjective but any comments if I'm heading in the right direction.

My ideal setup is
(a) to have a root partition that can easily be formatted/upgraded
(b) not have to touch the main MBR if I can (hence the separate /boot).
(c) as much isolation between the two OSs (hence the separate drives.unluckily, still need ntfs on HD B)
Are there any other advantages to having separate /boot? Also, how about /boot on a floppy or a CD? Is the numbering correct for grub menu.lst ? i.e root= /dev/hdb2 is the correct pointer? And how do I denote the "device for boot loader installation" which deaults to (hd0)?


/dev/hdb0 ntfs windows (apps- can't get rid of this yet)
/dev/hdb1 /boot primary ext3 300Mb
/dev/hdb2 / primary ext3 10Gb
/dev/hdb4 /home logical ext3 100Gb
/dev/hdb5 /usr logical ext3 10Gb
/dev/hdb6 /usr/local logical ext3 10Gb
/dev/hdb7 /var logical ext3 10Gb
/dev/hdb8 swap primary swap 2Gb


Feel free to point out alternatives (including different partition types) and logic behind using them.

Thanks in advance!
HT

weibullguy 06-12-2007 11:02 PM

Too much swap. 512MB is probably more than enough unless you are doing some serious number crunching. I use my Linux box to simulate repairable system availability over 10, 15, 20+ year periods with hourly resolution (that's about 11.2 billion calculations needed for one simulation run). The most swap I've seen used on my box was about 100MB with 1GB of RAM, but I was on the internet and reading e-mail at the same time. The only time I ran out of swap was running the Octave Forge test suite, but who does that more than a few times in their life.

I'm sure you have a reason for /usr/local and /var on separate partitions. If it is a single-user box, I don't see the need for /usr/local on a separate partition because not much will be installed there so you'll waste 10GB. Think about having a slightly smaller partition mounted at /var/log instead of /var depending on what you expect to be in /var.

Yeah, I do a separate partition to mount at /boot and unmount after the machine boots. There's nothing you need there once the kernel is loaded and controlling everything. My CLFS kernels are stored in /boot/clfs and my Gentoo kernels are in /boot/gentoo. I also use a separate partition (24GB) and mount it at /multimedia for mp3's and video files. This can be shared between distros (and with XP). I also have a separate partition mounted at /srv primarily for MySQL. Finally, I have another mounted at /usr/src since I build everything from source, I don't want a bunch of tarballs and source trees cluttering up /.

My two cents FWIW.

mailforbiz 06-14-2007 09:08 AM

Thanks for your detailed response...it's definitely helpful.

I will probably do away with /usr/local and reduce the /var. I thought about the /multimedia but just went with the /home. /usr/src is a good idea though if I ever want to rebuilt stuff.

Question: What happens when I reinstall? Which partitions will be overwritten and which won't be touched? I suppose the /boot and / will be reinstalled and most likely /usr but what about /var or /usr/local?




Quote:

Originally Posted by weibullguy
Too much swap. 512MB is probably more than enough unless you are doing some serious number crunching. I use my Linux box to simulate repairable system availability over 10, 15, 20+ year periods with hourly resolution (that's about 11.2 billion calculations needed for one simulation run). The most swap I've seen used on my box was about 100MB with 1GB of RAM, but I was on the internet and reading e-mail at the same time. The only time I ran out of swap was running the Octave Forge test suite, but who does that more than a few times in their life.

I'm sure you have a reason for /usr/local and /var on separate partitions. If it is a single-user box, I don't see the need for /usr/local on a separate partition because not much will be installed there so you'll waste 10GB. Think about having a slightly smaller partition mounted at /var/log instead of /var depending on what you expect to be in /var.

Yeah, I do a separate partition to mount at /boot and unmount after the machine boots. There's nothing you need there once the kernel is loaded and controlling everything. My CLFS kernels are stored in /boot/clfs and my Gentoo kernels are in /boot/gentoo. I also use a separate partition (24GB) and mount it at /multimedia for mp3's and video files. This can be shared between distros (and with XP). I also have a separate partition mounted at /srv primarily for MySQL. Finally, I have another mounted at /usr/src since I build everything from source, I don't want a bunch of tarballs and source trees cluttering up /.

My two cents FWIW.


weibullguy 06-14-2007 10:15 AM

All of them may/will be altered.

Take /boot for example. Mine is on a separate partition (hda1) and I have manually created the subdirectories gentoo and clfs for gentoo and clfs specific files. Currently, hda9 is mounted at / when I use Gentoo. Now assume that I want to reinstall Gentoo on hda9. The installation process will create a /boot directory on hda9 with the Gentoo specific files. I would then and copy these Gentoo files from hda9 to /boot/gentoo on hda1. Then I would edit grub.conf and the reinstalled Gentoo's /etc/fstab and viola, my reinstalled Gentoo is sharing the /boot partition with CLFS. In this case only hda9 was overwritten and all the other partitions were left untouched.
Hopefully that makes some sense.

Take an alternate example. Now when I reinstall Gentoo, I tell the installer to use hda9 for / and hda1 for /boot. When the installation is complete both hda1 and hda9 will have been overwritten. I would have lost the CLFS files and would then be unable to boot into CLFS. This would be bad since I use CLFS every day and it would make me cry. :cry:

To answer some questions I ignored from your original post...

The MBR and the partition that mount at /boot are not the same thing. If you do not reinstall your bootloader (GRUB, LILO, etc.), your MBR will remain untouched. The advantage of using a separate partition for /boot is that it can be unmounted after the kernel is loaded; your system is more secure and less susceptible to the, "Oooops, did I just delete that?" virus.

Installing GRUB (including using a floppy, CD, or installing to other than hda) --> http://www.gnu.org/software/grub/manual/grub.html. Read the 'INSTALLATION' section. However, GRUB will boot Windows, so there's no harm installing GRUB on hda.

Yes, /dev/hdb2 is correct for GRUB.

Hopefully that all makes some sense.


All times are GMT -5. The time now is 07:42 AM.