Partition Question

mrunion · 2007-08-31 15:26:07

I have Arch installed on my laptop on my SECOND HDD. The first HDD is 80GB and all Windows XP. the Second HDD is 80GB but has 4 primary partitions, arranged like this:

/dev/sdb1 -- Windows XP Approx 40GB
/dev/sdb2 -- Linux install EXCEPT for /home Approx 30GB (ext3)
/dev/sdb3 -- Linux /home Approx 10GB (ext3)
/dev/sdb4 -- SWAP

What I'd like to do is one of two things -- and I want to do which ever is LESS painless. I want sdb1 to either shrink down to 10GB or so, and sdb2 and sdb3 to grow. Maybe something like sdb1-10GB, sdb2-50GB, sdb3-30GB. (I'll take suggestions here!) Or I can ditched the sdb1 partition all together.

To manage booting the computer I use Acronis Disk Director. It finds bootable partitions on its own and allows them to be booted. It also has alot of other tools that let you resize partitions, etc. This is THE BEST tool I've found for this stuff! Anyway, I don't have GRUB installed to the MBR, but I do have it installed to the boot sector (?) of the root partition (sdb2).

Now, it's my THEORY that if I resize sdb1, sdb2 and sdb3 that they will still boot just fine -- because their order didn't change or anything. Is this theory correct? What about GRUB being installed to the boot sector on sdb2? In theory that "position" on the drive will move when the partition gets bigger, right? If I REMOVE sdb1, I'll need to modify /etc/fstab, but I don't know if GRUB will need any "help" because it's not installed on the MBR. My suspicion is that it will.

Can anyone shed some light on this for me? Oh, and I plan on using the SystemRescueCD to make backups before doing anything -- just in case....

Thanks in advance.

aythun · 2007-08-31 19:01:41

If you just resize your partitions, GRUB won't care. It doesn't remember the exact position on the disk where its configuration is, it just reads the filesystem like anything else.

If you completely remove the first partition, all the other ones will fall back a number. In /etc/fstab you will have to make changes like /dev/sdb2 -> /dev/sdb1. In GRUB, you'll have to do stuff like hd(1,1) -> hd(1,0). You'd need to do this even if GRUB was installed to the master boot record of your master drive.

mrunion · 2007-08-31 19:33:28

Thanks! I'll just resize the partition then. That'll be a good starting point anyway. If I ever want it completely gone I'll do the rest of the stuff.

mac57 · 2007-08-31 20:22:46

I might ask why you want to make the Linux install partition any larger. I would be making the /home partition the largest, since that is where all your personal data resides, and hence needs the extra space most. For myself these days, I tend to make the Linux install partitions about 12 GB and then use a separate partition for my home directory, usually much, much larger. Even at 12 GB, a fully loaded Arch install isn't using much more than half of that 12 GB. My advice? Don't waste space on the Arch install partition - waste it on your /home.

So, I would recommend:

/dev/sdb1 - 10 GB (per your request)
/dev/sdb2 - 12 GB (Arch installation)
/dev/sdb3 - 58 GB (/home)
/dev/sdb4 - SWAP

By the way, note that if you install the Windows XP support for ext2/3, you can access your Arch /home from within Windows, which is actually how I set it up, making /home a shared common data directory between both OS'!

See:

http://www.fs-driver.org

for the Windows installable ext2/3 file system. I have used it for over a year now - it works well. The only gotcha I have seen is that when your /home partition reaches the maximum mount count that forces an e2fsck operation in Linux, if the next mount is from Windows, it simply fails to report the drive any more. You have to boot Linux, let it do the e2fsck, and then go back to Windows, which once again "sees" the drive now that it is back below the maximum count. I've been caught out this way once or twice when doing a lot of config work on the Windows side of my dual boot and restarting over and over and over, with each restart adding one to the mount count.

Now that you can share your /home with Windows, of course this suggests the possibility of eliminating your /dev/sdb1 entirely at this point, and adding another 10 GB to /home. This is a good idea although you do have to do a little more work due to the shift in logical disk numbers for your Arch and SWAP partitions.

Last edited by mac57 (2007-08-31 20:26:06)

mrunion · 2007-09-03 01:11:34

Good points. I think I may do that!

Thanks!

mrunion · 2007-09-04 16:59:22

For what it's worth I had to reinstall GRUB to the boot sector of the partition. I jsut botted the Arch Install CD, went to Grub command line, did the "root (hd1,1)" and then "setup (hd1,1)" and all was back to normal.

I resized the partitions and ended up with this:

Windows/NTFS 20GB
/ 30GB
/home 25GB

These are approximations only.

Thanks guys!

Arch Linux

#1 2007-08-31 15:26:07

Partition Question

#2 2007-08-31 19:01:41

Re: Partition Question

#3 2007-08-31 19:33:28

Re: Partition Question

#4 2007-08-31 20:22:46

Re: Partition Question

#5 2007-09-03 01:11:34

Re: Partition Question

#6 2007-09-04 16:59:22

Re: Partition Question

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