Get help on partitioning here [Part 3]

UlisesFrank · n00b Joined: 21 Feb 2016 Posts: 1

Hi all.

This would be my first time installing Gentoo, and I would like it to get it right.

I'm not that into having many partitions.

I have a 500 HD and 3 GB of RAM with an Intel Core2 Duo T5800 processor, Intel Mobile 4 Series Integrated Graphics Controller. Kind of old laptop. I am currently running Manjaro 15.12 XFCE 64 bit. I have never put a distro with something more than a XFCE because of my RAM (I don't think it would go smooth with a KDE or GNOME)

I only have 4 questions xD ...

#1 If I install a KDE in Gentoo, noting that it would not be as "stressed" as in other distros, would it run somewhat "smooth" in the laptop? (with what I use, I rarely reach 1GB of usage)

#2 I tried installing first in VirtualBox, following a YT video and the Handbook Guide, but I used "mklabel gpt" and in the end it could not recognized my GRUB... I originally have GRUB Legacy, so, I should have done it with "mklabel msdos", isn't it? And, I can install GRUB2 without problems as the Handbook says, don't I?

#3 I really don't like to dual boot, so I would get rid of everything (even though maybe later on set it with Arch).

I was thinking in (IF ONLY GENTOO):
/boot 256 MB (I usually have 2 Kernels at all times, I don't know if in Gentoo, as it suggests you to configure one, is it at all necessary or common to have more than one?)
/root DON'T KNOW (as I always tend to merge /home in /root, but reading previous posts, and knowing that compiling takes its time, I think I'd go with a separate /home)
/swap 3G (I tend to suspend and sometimes hibernate)
/home THE REST

I don't tend to install too much software. Only one or two browsers, libreoffice, deluge (or similar), gfw (or similar), VLC, Plank, etc... minor stuffs. And don't play much (or at all)

If I would like to dual boot in the future, the following chart is a good tree?:
dev/sda1 /boot primary ext4 (300 MB, and it would boot both GENTOO and ARCH)
dev/sda2 extended
-sda5 /root GENTOO ext4
-sda6 /home logical ext4
dev/sda3 /swap primary swap (For both GENTOO and ARCH)
dev/sda4 /root ARCH primary ext4

Well, thanks so much in advanced for your answer.

Edit by NeddySeagoon
Created Get help on partitioning here [Part 3] by splitting from Part 2

NeddySeagoon · Posted: Sun Feb 21, 2016 2:57 pm Post subject:

UlisesFrank,

Welcome to Gentoo.

The topic had reached 30 pages, which is about the limit for a topic size. I hope you don't mind being first in part 3.

KDE in Gentoo will be just as stressed as in other distros because in both distros, you only run the parts you use.
Gentoo can save you bloat, so the parts you don't use are neither compiled, so they don't take up space on your HDD, nor loaded into memory.
In fact, because of the way kernel memory managment works, things are not loaded until they are needed anyway.
Things can be built for your CPU in Gentoo - unlike in binary distros, where they need to run anywhere.

Will it be smooth? That's a hard one ... test it. You can install as many windo managers/Desktop Environments as you like and switch between them.

Mixing BIOS and GPT mostly works. The trap for the unwary is that a GPT disklabel also gives you a 'protective' MSDOS disklabel for free.
The BIOS can only read the 'protective' MSDOS disklabel. If you need to set the bootable flag, it must be set on the 'protective' MSDOS disklabel, not on any partitions in the GPT partition table.
I say mostly works as I've met one Dell BIOS that checks the partition type holding the bootable flag. That makes life really difficult.

If you think you may wish to dual boot later, be sure ta have a separate /boot that you will share with all of your multi boot installs. Its not essential but it will save your sanity.

/boot 256 MB That's plenty. I have 3 or 4 kernels and an initrd in 40Mb.
/root go for 40G. It looks like a lot but Gentoo stores source files in /usr/portage/distfiles, builds things in /var/tmp/portage which you don't do an a binary distro.
It saves kernels in /usr/src ... about 1G per configured and built kernel.
/var/tmp/portage needs to be at least 6G if you want to build libreoffice or at least 12G if you like Palemoon.
/var/tmp/portage is only used for build temporary space - you get it back later.

You might like to consider using Logical Volume Manager for everything except /boot and possibly swap, so you can move space around or make more logical volumes later.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Lophophora · n00b Joined: 02 Oct 2006 Posts: 27

Hi all,

After a long number of years on my old desktop (still with ATA drives), I've decided to upgrade to a new system and repeat my previous dual boot setup with Gentoo/Windows 10. I could use a lot of help on partinitiong as things have moved a long way since I did my last gentoo installation and I haven't really kept abreast with the new hardware

The new system will have a 128GB M.2 2280 SSD, a 3TB HDD and possibly also a 1 TB HDD (currently debating whether to have it as an external hard drive or not). Given I want to have dual boot, I was wondering if someone can offer some advice on possible partitioning schemes and also whether to use UEFI or not.

Should I simply go for clean installs on each drive, would that make things easier from a partitioning point of view?

Thanks in advance!

NeddySeagoon · Posted: Thu Jul 07, 2016 7:27 pm Post subject:

Lophophora,

Windows 10 expects you to use UEFI.
Install windows first but do a manual partition, so it doesn't help itself to the entire hard drive.

After that, install Gentoo however you like. Its worth putting /usr/portage/distfiles on rotating rust as it can get quite large.
/usr/portage/packages, if you have it, can also be on a conventional HDD.

Portage on SSD is nice but its a space hog. The SSD will force the use of a 4kB block size. If you don't have a need for speed, put it on the HDD or possibly squashfs on the SSD.

Put /var/tmp/partage in tmpfs. This avoids disk writes that are never read. It won't be any faster, since if you have the RAM to do this, the kernel will use it for disk cache anyway.

/var/log is one of those, where it depends on your individual use case. If you send all the build logs here, it can get quite big.

Think about using logical volume manager. Its another layer of abstraction but it allows you to move free space around.
Adding existing free space where its needed is on online, no reboot activity. Moving already allocated free space is harder.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Lophophora · n00b Joined: 02 Oct 2006 Posts: 27

Thanks Neddy!

So if I understand you correctly, at the very least the /boot partition should be on the same drive as the windows installation? In the past I've tried to keep the two OS completely separated as it enabled be to use the BIOS boot order almost as a 2nd layer bootloader. From what you're saying it sounds like I have to have the bootloader in whichever drive windows gets installed, correct?

NeddySeagoon · Posted: Fri Jul 08, 2016 6:44 pm Post subject:

Lophophora,

If you put windows and /boot on different drives you can avoid breaking windows when you install grub.
This way you get one PC with two boot loaders. The boot loader that is called depends on the boot drive selected in the firmware.

A worked example may help
You install Window on (a part of) /dev/sda. The Windows bootloader goes in the MBR of /dev/sda.
You put Gentoo /boot on /dev/sdb The Gentoo bootloader goes in the MBR of /dev/sdb

At this point you have two totally independent installs and choose which to boot by selecting the boot drive.
That's not very user friendly but there is another step.
The Gentoo bootloader can chainload the windows bootloader. This is a menu entry in the Gentoo bootloader. The Windows install is not changed.

When you gen to this stage, you choose /dev/sdb (Gentoo) as the bootloader and use the menu to pick any of your installed operating systems.
That's considered normal operation.

Fall back, if Gentoo won't boot for some reason, is to select /dev/sda as the boot drive and boot windows directly.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Catanduva · Posted: Fri Sep 16, 2016 4:39 pm Post subject:

I got some questions.

I have gentoo on a 1Tb HDD and i'm buying a 120gb SSD. I plan on dual booting Windows 10 for games so i think it's easier to put Windows on my HDD since games are so big that nowadays that the SSD wouldn't be big enough.

What should go on SSD and what should go on HDD for gentoo? Personal files (/home) shouldn't matter, right? HDD has more space so it stays there. What about /var/tmp/portage?

If i got this right it should be:

SSD:
/boot
/

HDD:
/home
windows

TMPFS:
/var/log/portage

Is that ok or is there anything i could do to make it better? Also, what options do i put on fstab regarding SSD? Is there any difference?

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

Catanduva · Posted: Fri Sep 16, 2016 5:02 pm Post subject:

NeddySeagoon · Posted: Fri Sep 16, 2016 8:16 pm Post subject:

Catanduva,

On conventional HDD, the data is not erased when you delete a file. The space it occupied is marked free, so it can be reused and the pointers to the file are cleared. The data stays in place until its overwritten.
This means that its possible to recover files on a conventional HDD until they have been overwritten. That may take days/months/years depending on how fast space is reused and how full the filesystem is.

SSDs must be erased before that can be written an the write process can only change 0's to 1's, not the other way around.
Also, the erase process is very slow compared to reading and writing. SSD's provide a function called trim, which some filesystems can use to tell the SSD that certain data blocks are no longer needed and may be erased, ready for the next write.
After the SSD has been given the trim command for some data, its up to the SSD when the blocks are actually erased. You cannot count on being able to do any data recovery at all. You need backups.

A few SSDs have been shown to have buggy trim commands too. Usually, only for rare corner cases.
In these rare corner cases, you may lose data that was not supposed to be trimmed. This is a very bad thing. You need backups.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Catanduva · Posted: Sat Sep 17, 2016 11:08 am Post subject:

GalaticStryder · n00b Joined: 23 Oct 2016 Posts: 4

Hello everyone, I'm about to get my second shot on Gentoo. The first one was frustrated since I was using a rather complex partition scenario with openSUSE on LVM together LUKS, I couldn't make grub2 initialize using openSUSE's cloned fstab in gentoo (just pointed the new UUID for the new volume I had create for Gentoo and removed the mounts we don't need...) it didn't work properly but it was totally my fault although I didn't bother since I'm getting a new SSD this week and thus I need to ask for some advice on the partitioning task.

- I want to create a simple scheme using LVM and possibly encrypt it with LUKS as I'm using on openSUSE right now.

Here's my current fstab/lsblk:

ecko · Tux's lil' helper Joined: 04 Jul 2010 Posts: 111

Hey GalaticStryder, I came here to get help but I can answer on one detail:

br4n_d0n · n00b Joined: 13 Nov 2016 Posts: 4

Hi, I'm very new to Gentoo and wanted to get some suggestions from more experienced people on a good partitioning scheme for a hypervisor build. The plan is to have Gentoo as the guest with PCI passthrough and I'm looking at using ZFS.

I'm hoping that the people providing partitioning ideas can list the pros and cons of their suggestion.

Hardware:

1 x 256GB SSD
4 x 4TB HDD (thinking of zfs volume with 2 mirrors striped)

Note: I have some additional drives ranging in sizes from 1TB-2TB, but I'm not sure what to use them for at this point in time.

NeddySeagoon · Posted: Sun Nov 13, 2016 10:55 pm Post subject:

br4n_d0n

Welcome to Gentoo.

What PCI device(s) do you want to pass through?

Raid10 (2 mirrors striped) is usually a bad idea. It protects against and one drive failure and some combinations of 2 drives failing.
What in your motive for using Raid?

Tell us about both the host and the guest.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

br4n_d0n · n00b Joined: 13 Nov 2016 Posts: 4

I'm looking to pass a video card to the guest vm on both Windows and macOS. Only one of these vm's will be running at a time. I was also looking at a raid mirror because I heard that it would be better for vm's instead of a raid-z. My purpose in going with zfs using a mirror or raid-z, is for some data integrity and to keep me from being hosed if a drive failed. I know none of this is a substitute for a proper backup.

NeddySeagoon · Posted: Sun Nov 13, 2016 11:29 pm Post subject:

br4n_d0n,

I use lvm over raid5 on the host and pass a logical volume to a guest, which it uses as its HDD.
There is no host filesystem involved.
This avoids having a filesystem in a file on another filesystem, which can be slow.

I've not tried PCI passthough with a video card but I did with a Intel 4 port NIC.
Unfortunately, it has a hardware bug that prevents it from working.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

br4n_d0n · n00b Joined: 13 Nov 2016 Posts: 4

Where does the data integrity come into play then with a LVM?

NeddySeagoon · Posted: Sun Nov 13, 2016 11:54 pm Post subject:

br4n_d0n,

Its provided by the underlying raid.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

br4n_d0n · n00b Joined: 13 Nov 2016 Posts: 4

Sorry, I'm confused; I thought you said that you would use lvm over using a raid. So, where does the raid come from?

Hu · Administrator Joined: 06 Mar 2007 Posts: 22717

I think he meant that he places an LVM on a RAID device, so the stack is:

- Hard drive, one or more (sdX)
- MD (RAID) device composed from the hard drive(s) (md)
- LVM physical volume created on the virtual block device representing the RAID

That lets the RAID layer handle redundancy and the LVM layer handle size and layout of the data.

UechyLibre · n00b Joined: 05 Dec 2016 Posts: 7

So I am going to reinstall Gentoo because I am getting out of space on /

I have a 128G SDD and 1T HDD 8GB of RAM and i7-3770k

I would manually compile linux-libre kernel and other apps that are not on portage tree(icecat for example). I also would like to start learning programing and making my own .ebuilds for those packages.

EDIT: I have 25 GB on / and they are full...

I also have a intelcore2 with 2 GB of RAM and 500GB HDD in wich i would install a mail server (or at least I am going to try it)

Hu · Administrator Joined: 06 Mar 2007 Posts: 22717

25G in / should be plenty. I have /usr on / and have ~6G used for a desktop system with X and a basic window manager (note, no KDE or GNOME). Before you reinstall, you should find what used up so much space on / and investigate whether you can reclaim space in a less drastic way.

UechyLibre · n00b Joined: 05 Dec 2016 Posts: 7

NeddySeagoon · Posted: Wed Dec 14, 2016 10:24 am Post subject:

UechyLibre,

Read