[mythtv-users] swappiness

[Marius Schrecker]

On Friday, February 12, 2016 14:42 CET, Eric Sharkey <eric at lisaneric.org> wrote:
 ...
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The question you should be asking is if you want swap at all. What
sort of "emergencies" are you expecting?Was thinking that swap might be essential if something /anything / a memory leak leaves the system in a OOM state.  I thought that the result of that wpould be a complete lockup of everything, including any dirty pages and the only way out would be a hard reset, with risk of disk trashing.  
If you want a reliable system, you may actually be better off without
swap at all than with swap set to an old spun-down disk. You may find
out two years from now that the disk won't spin up when you finally do
need swap, and the kernel's OOM killer might have actually done a
better job for you than handling this swap-device unavailable state.​I wasn't aware of a OOM killer and see the point about an old and possible defective hard drive being a worse option if the system suddenly needs it.

So if I forget using an old HD, what would be safer?

1. A very low swappines (0) and swap partition (or file) on the SSD?
2. No swap at all and total relieance on the OOM killer if ever needed?
> 4. What about the rest of /var ? Better on the SSD (where log/ will cause
> writes) or on the media disk, where it will compete on a small way with
> access to the media files? On my old system /var/ excluding lib/mythtv was
> only a few hundred MB in size.

...
...
9 Power_On_Hours 0x0000 --- --- --- Old_age
Offline - 48721
209 Remaining_Lifetime_Perc 0x0000 --- --- --- Old_age
Offline - 98

48K hours on, 98% life remaining.

EricLooks promising!  Have you done anything to limit logging? tempfs or any other hacks to limit the impact on your SSD?

BR.

--Marius--
 
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