SSD Corrupted Due To SWAP Space

Question

I Have a brand new high speed mSD card perfect for LVM-FullDisk-Encryption. Problem is, Non-Volitile SolidState memory has a finite amount of write cycles that will rapidly decrease at an alarming rate due to SWAP data constantly written to it. FINE! I dont need SWAP space, I'll leave it out of my Table. However I left it thinking my RAM would cover me enough the system might not find it necessary to allocate from there. I figured if I got really worried I can track my memory usage thru SysMonitor but I dont trust it yet, I havent peaked my RAM to see any result other than zero usage. I cant find my swap space, any thoughts? Will I be able to disable my swap without knowing where it is?

What are you actually asking? How to disable swap? How to monitor swap use? How SSDs handle swap? How to track memory use? — vidarlo, May 22 '18 at 11:03
You may be worrying for nothing. Unless your SSD is ancient it should easily be able to endure at least writing 500 times it's capacity; that is, even the cheapest modern 200 GiB SSD ought to be able to endure 100 TiB written. Use smartctl to see how many bytes have been written to it during its lifetime. Before anything else you may want to look up your SSD's actual endurance, either as drive-capacity-per-day or total TiB written. — AlexP, May 22 '18 at 22:39
Based on information you provided, you cannot find your swap space because you did not create a swap partition. You can try creating a swap file or using compressed RAM as swap (sudo aptitude install zram-config). — xiota, May 24 '18 at 18:36

Elder Geek · Answer 1 · 2018-05-22T22:36:22.123

Here's some useful CLI commands to help you make sense of what's going on.

The first is the command free which will provide results similar to what you see below:

              total        used        free      shared  buff/cache   available
Mem:        7614996     1855044     3592444      202500     2167508     5197716
Swap:       1048572      594772      453800

As you can see above I have 1048572 bytes of swap reserved on my system and am currently using 594772 bytes of it. the 2167508 bytes of buff/cache makes it plain that I don't have to be using swap and can safely turn it off completely with the command sudo swapoff -a

AS is clearly stated on the man page which you can see if you issue the command man swapoff

swapoff  disables  swapping  on  the specified devices and files.  When the -a flag is given, swapping is disabled on all
       known swap devices and files (as found in /proc/swaps or /etc/fstab).

Having issued the command sudo swapoff -a I can confirm that it's off even though I didn't specify where it was by running free again and the results are:

              total        used        free      shared  buff/cache   available
Mem:        7614996     1978976     3297572      379672     2338448     4905560
Swap:             0           0           0

Edit: Note that to turn swap back on without knowing where it is you can issue the command sudo swapon -a

I believe this concise answer should eliminate any concerns you have about trusting SysMonitor as it doesn't use it, explains how you might find your swap space if you set it up, and how to disable and re-enable it without knowing where it is.

SSD Corrupted Due To SWAP Space

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