Ubuntu – n official tutorial for installing Ubuntu 18.04+ on a device with an SSD and an additional internal hard drive

Install Linux to the SSD (100GB is much more room than needed) after configuring your machine's BIOS to set the SSD as sda and the HDD as sdb, and make the SSD (sda) the boot drive.

When the installation process comes to partition, set up both drives with the default filesystem ext4 - and swap goes at the back of the HDD as per normal. You can also revised that after installation ends with the Gparted utility of Ubuntu.

Leave about 10%-20% of the space on the SSD unallocated, for as the SSD ages, specific addresses will fail, and the SSD will automatically block those and replace them with addresses in the unallocated space. Also, this “Over-provisioning” boosts an SSD’s sustained write performance by allocating temporary space as discussed at http://www.tweaktown.com/reviews/5822/sandisk-x210-256gb-business-class-ssd-exploring-overprovisioning/index.html . The ext4 partition on the SSD should be about 80-90% of the total space, or 103GB-115GB, with about 13GB-25GB left unallocated, outside that partition.

After installation, modify the filesystem by editing /etc/fstab to put /tmp /var and /home on sdb along with swap, and add the ,noatime parameter to sda , then save and reboot.

The purpose of noatime is to disable timestamping of file reads which cuts down the number of I/O ops. Should a program need timestamping then remove noatime which in Ubuntu will default to relatime instead which keeps the timestamps more or less accurate with only a slight uptick in I/O.

A good detailed article on the subject can be found at https://wiki.debian.org/SSDOptimization and examples of what /etc/fstab should look like may be seen at https://wiki.archlinux.org/index.php/SSD#noatime_Mount_Flag and at http://forums.debian.net/viewtopic.php?f=16&t=76921

Step by step tutorial (just skip what you already did):

1. Boot from the installation drive

Create a bootable USB drive with the installation image and then boot from it to begin the OS installation.

2. Go through the installation process

Choose the options that suit you best. When prompted to choose instalation type, select "Something Else" to create the partitions for the OS. To create a partition, just click the "+" sign on "free space". You will need to create the following partitions on your SSD:

• root
  • Size: 30-50GB
  • Type: Primary
  • Use As: ext4 Journaling file system
  • Mount Point: /
• swap (optional)
  • Size: see this post to decide on a size (and whether you want swap at all)
  • Type: Logical
  • Use As: swap area
• home (optional, check this post for more info)
  • Size: the rest of your free space, generally
  • Type: Logical
  • Use As: ext4 Journaling file system
  • Mount Point: /home

3. Set up your HDD to mount automatically on boot

Easiest way to do this imo is through the gnome-disks GUI tool (to use it, just open a terminal - Ctrl+Alt+T, type in sudo gnome-disks and enter your password). Select your HDD, click on the cogwheels -> "Edit Mount Options...", enable "Mount at system startup" and choose a mount point (for example, /mnt/sda1 or whatever that device is identified as, or /media/user/DATA).

4. Link ~ (/home/user) media folders to the HDD for easy access

You will have a few default media folders in your ~ folder, which you might want to have on the HDD instead. To move them to the HDD while still being able to access them easily from /home/user, you will need to move those folders to the HDD (or just delete them and create other folders) and then create symbolic links instead, using a terminal command like:

ln -s /mnt/sda1/Downloads ~/Downloads

That's it! You're all set!