Hybrid SSD and HDD setup on laptop with Mageia 4

[duncangareth]

I have a Lenovo Thinkpad W510, which is a respectable bit of kit, especially when it comes to running Mageia. I have removed the optical drive and replaced it with a special plugin HDD cradle into which I inserted the original HDD. In place of the original HDD, I installed an SSD.

Using an external DVD drive, I installed Mageia 4, and when it came to the partitioning of the drives, I created a root file system on the SSD, as well as a /usr file system. On the HDD I created /home and /var.

The options in /etc/fstab for the two SSD based file systems are "noatime,errors=remount-ro,acl,discard".

Have I missed anything?

The system does perform very well, but I wonder about /tmp. Ideally it should be on the HDD. /var/tmp is fine, but I am worried that /tmp will cause too many writes to the SSD, thus shortening its life.

Am I being paranoid?

[doktor5000]

The system does perform very well, but I wonder about /tmp. Ideally it should be on the HDD. /var/tmp is fine, but I am worried that /tmp will cause too many writes to the SSD, thus shortening its life.

Am I being paranoid?

Maybe a bit

Previously I've had an OCZ Agility 3 for nearly 3 years - never setup TRIM on that one, and used it heavily for rpm building,
compiling stuff, /tmp was also on that disk, browser cache and all that stuff. Never had any issues. Still using it, only got too small.
Now I've got a Samsung 840 Pro, also not setup TRIM, and only use fstrim once every few months.

One thing you should pay attention to, using discard in fstab is usually not recommended.
Better run fstrim regularly. Check https://wiki.mageia.org/en/Installation_on_a_SSD_(Solid_State_Drive)#The_trim_command

What SSD do you have, is it brand new, or already used?

[duncangareth]

Thanks for your advice. I shall read the article.
The SSD I am using is an OCZ-SOLID3 which had probably been used before. I bought it at a bargain price from some blokes in Tottenham Court Road the last time I was in the UK.
What would you consider to be the main danger of using "discard"?

[duncangareth]

doktor5000, I have read the article you recommended.
So, the optimal way to handle trimming is to run it as a cron job. That makes sense. Do you think the performance increase would be significant? I suppose it would be dependent on how busy the system is.
I shall implement the kernel scheduler change directly

[doktor5000]

Well, if you use discard, for every write there will be a TRIM beforehand, so that performance impact is probably worse.
IMHO if you don't benchmark the SSD regularly or use them for some mission-critical stuff, you won't notice a difference in any case for regular usage.

[duncangareth]

Hiya Doktor

That makes sense. I don't think the impact would be too huge on my setup, though, because the only time I delete stuff from the SSD is when I am installing or removing software. The actual data manipulation happens on an HDD anyway.

[doktor5000]

Using an external DVD drive, I installed Mageia 4, and when it came to the partitioning of the drives, I created a root file system on the SSD, as well as a /usr file system. On the HDD I created /home and /var.

Ahh, just read that. If you really want to benefit from the SSD, definitely at least move /home onto the SSD,
otherwise you will waste a lot of the benefits, trust me. Actually I'd put the complete OS on the SSD, always.

[duncangareth]

Hey Doc

I think I shall give that a try. I think I might just move the /home stuff onto another SSD I have and give it a whirl.

cheers
Duncan

[JohnnyEdwards]

Hey guys! I would also like to try your advice on my ssd. Thanks for the info. http://www.bestsellingreviews.com/Computer/Solid-State-Drive/