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I have read of a lot of questions about SSD optimization (How do I optimize the OS for SSDs?, Installing Ubuntu on a SSD, I'm confused about SSD optimization, etc...).

Most of those questions seem outdated (3+ years old) and I am a little bit confused with all the directions the answers are taking.

So my question is : As of today, what is the general consensus about SSD optimization on Ubuntu 14.04 / 15.04 ?

Is this even needed now ?

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hg8
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    "Mandatory" read: https://sites.google.com/site/easylinuxtipsproject/ssd The tips there are still valid. And it sums it up very nicely for any pointer you need. From the way it is used by Ubuntu, through to browser settings. – Rinzwind Sep 15 '15 at 08:22

4 Answers4

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The thing is , first most important part about SSDs is minimizing the writes to the disk, which is why people add nodiratime, noatime to the /etc/fstab file.

Second , is running TRIM which reclaims unused blocks of NAND memory back to SSD. Windows has TRIM enabled by default, AFAIK, so no one bothers there. With Ubuntu, it does have a weekly cronjob for TRIM, however for I've learned from Rinzwind's answer that the cron job only runs on Intel and Samsung SSDs. That's why you have to edit that /etc/cron.weekly/fstrim file to have exec fstrim-all --no-model-check line, so that it runs no matter what is your SSD model.

Over the recent years, this has not changed - these are still key points , minimizing writes and enabling TRIM.

Removing writes and expensive storage amount is the two factors why people also remove swap area. By default, Ubuntu creates swap partition equal to your RAM size. I have a 128 SSD and 6 GB of RAM. That means that by default Ubuntu will chop off 6 GB from 128GB, leaving 122GB for my OS, and 5% is typically reserved for root, so that leaves me 122-122*0.05=115.9 GB for myself. I might as well use that storage for something else, which is why I have only one main partition, no swap partition, but I do have a 512 MB swap file as a protective feature (not that I plan on running out of RAM, but it's always recommended to have swap)

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Sergiy Kolodyazhnyy
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  • About noatime - some applications may rely on comparing modification and access times, they may dysfunction, realtime is better and since Linux kernel 2.6.30 it is on by default, no need to set it up. You can check how your file systems were mounted running command $ cat /proc/mounts – Mike Sep 15 '15 at 16:14
  • @Mike Just ran the cat /proc/mounts. For my disk it doesn't show relatime enabled, only noatime and nodiratime which i explicitly enabled in /etc/fstab. As for noatime , can you provide some examples of which applications rely on it ? – Sergiy Kolodyazhnyy Sep 15 '15 at 16:21
  • If you have set noatime and nodiratime yourself, it may be the reason why realtime is not on by default. Applications relying on atime are for example mail program Mutt, MySQL binary logs, InnoDB log files, tmpwatch, some backup programs and file sync apps, ... But one can overcome that by setting up separate mount for file system that needs atime. – Mike Sep 15 '15 at 16:30
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    Sorry for typo realtime I meant relatime. – Mike Sep 15 '15 at 16:39
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    noatime implies nodiratime, see man mount about noatime: Do not update inode access times on this filesystem (...). This works for all inode types (directories too), so implies nodiratime. In addition, IMHO it isn't necessary to use noatime when relatime would probably won't break functionality and seems like a decent option (it is also recommended in: SSDOptimization at wiki.debian.org ). – Dor Aug 24 '16 at 19:59
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    Continue of my previous post: ... I wrote "decent" because that how many times it happens to files that their access time is earlier than their modify time? Especially regarding kernel files and all files which are in /. According to man mount: since Linux 2.6.30, the kernel defaults to the behavior of relatime. TL;DR Since Ubuntu 16, Avoid doing anything :-) – Dor Aug 24 '16 at 19:59
  • You should also configure the swappiness value to be very low so the swap is used only when absolutely necessary. – olfek Jan 11 '20 at 14:36
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The only thing you may need to do is to add --no-model-check to /etc/cron.weekly/fstrim.

The line should look this way

exec fstrim-all --no-model-check

Check that your SSD supports TRIM (almost all recent models do) by

sudo hdparm -I /dev/sda | grep "TRIM supported"

if your SSD is /dev/sda. If it does, add --no-model-check.

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It works fine with SSD which supports TRIM

for 16.04 there is no 

fstrim-all

simple fstrim does not have --no-model-check and it works fine with sandisk ssd

David Ambarsumov
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Generally Ubuntu supports Solid State Drives very well.
If you have an intel or a SAMSUNG SSD, automatic trim support is enabled by default.

You don't have to care about much with one exception:
You should store your personal data on a HDD to reduce the amount of writes to SSD.

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  • personal data rarely ever gets written to – endolith Sep 15 '16 at 01:30
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    "personal data rarely ever gets written to" except for browser cache, every document and spreadsheet you click Save, anything you download, any thing copy in to upload... – kmarsh Oct 09 '16 at 02:38
  • Isn't that exactly the purpose of a SSD? To speed up things like browser cache, etc.? And editing documents... Well, even if you edit 20 large documents everyday, which are 1 MB each, that's a max. of 20 MB of writes a day... That's not a lot. Not worth the extra hassle to add a HDD. – Andreas Jul 20 '18 at 08:01