Ubuntu – Disk setup with a small SSD and a large HDD

hard drivepartitioningssd

I have a notebook on which I on want to install Ubuntu 13.10 in dual boot with Window 8.1. It has an 500GB HDD, and a 24GB SSD used as cache in Windows. In Windows I disabled ExpressCache and unformatted the SSD.

Now I am looking for reasonable way to partition my drives while installing Ubuntu to make use of the SSD.

I looked on the internet, and there are different setups people use.

  1. Using flashcache/bcache. This is the same as ExpressCache in Windows. Advantages: Everything is cached and is cached automatically. Disadvantages: requires advanced setup; also, I'ma afraid something can break when Linux Kernel is upgraded.

  2. Putting / on SSD and /home in HDD. Advantages: very simple and robust setup. Disadvantages:

    I think I would put the /home directory on the SSD, but for most directories, especially the ones with large files, I would simply have a symbolic link to whatever contains the files. This way, you can keep your settings, and the browser cache, etc on the SSD, but put the pictures, sounds, documents, etc on whatever disk you want, which can easily be changed by changing the links.

  3. Putting / and /home on SSD, while making symbolic links for Downloads, Videos, .wine, etc. to HDD. Advantages: maximum cache. Disadavantages: micromanagement – to many things to fiddle with.

  4. Where to put swap partition?

https://askubuntu.com/a/289202/7064

Also, if you plan for a swap partition, put in on the SSD.

https://askubuntu.com/a/62161/7064

Do not put swap on the ssd. Put it on the hdd.

https://askubuntu.com/a/20154/7064

I wouldn't care too much about putting a swap-partition on a SSD. The swap is, like said before, only used if there's no RAM left. But then there are "few" sequential writes and "many" random reads. That's exactly a form of usage SSDs excel in.

What storage setup are you using? What are other advantages/disadvantages in each of the setups?

Also, though people say that modern SSDs are good with a lot of writes, I still don't trust them, especially as a read from my comments on my notebook that the SSD in it breakes quite often.

Best Answer

The first question I'd be asking is Can the SSD be trusted as a primary drive? This was built to be a a cache drive and cache data is usually a copy of something stored elsewhere. There's no need for that data to have any integrity. Invalid data? Just rebuild off the main storage. To use it as primary storage might not be a great idea because corruption there is permanent.

Next, Does it perform well? Cache SSDs are cheap patches to plug the hole that is the incredibly slow magnetic disk that laptops get. If it's unbranded (and there are no specs on the internet), give it a quick spin with the Disk Utility in a Live CD/USB

If the answer to these two is anything but "it's fine, it's a solid disk", I'd look at replacing it with a better mSATA (I assume that's the connection but check first!) SSD. Even ~60GB ones aren't that expensive and you can be a little more assured that they're not going to die on their first outing as a primary disk.


Where you plop your partitions is largely going to depend on how you use your system. I don't know how much user content you have versus installed applications.

For what it's worth, with a 120GB SSD, I have / and /home on SSD with things symlinked and bind-mounted over to RAID5 and RAID1 and NFS. Steam allows you to store things on other media so that handles itself quite nicely. And I occasionally manually copy things to SSD for speed and symlink them.

... But I have the space to make that possible. 24GB is really restrictive. I don't think that approach is going to work well for you.

You're not mentioning another option: Throw the crappy 5400RPM laptop drive into the ocean and buy a better SSD to replace it and use network storage for all the data you hold dear.

Laptops are awful permanent storage because they get stolen, lost and dropped. It might make sense to have a centralised NFS NAS where you keep all the important stuff.

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