<html><br />On Friday, February 12, 2016 14:42 CET, Eric Sharkey <eric@lisaneric.org> wrote:<br /> <blockquote type="cite" cite="CAC73aR3QAYtq9UnBeB+NRKVWOfCA1AWoXa4wrHJe=NntCRTZ0Q@mail.gmail.com">...<br />...<br /><br />The question you should be asking is if you want swap at all. What<br />sort of "emergencies" are you expecting?</blockquote>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. <blockquote type="cite" cite="CAC73aR3QAYtq9UnBeB+NRKVWOfCA1AWoXa4wrHJe=NntCRTZ0Q@mail.gmail.com"><br />If you want a reliable system, you may actually be better off without<br />swap at all than with swap set to an old spun-down disk. You may find<br />out two years from now that the disk won't spin up when you finally do<br />need swap, and the kernel's OOM killer might have actually done a<br />better job for you than handling this swap-device unavailable state.</blockquote><span style="line-height: 20.8px;">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.</span><br style="line-height: 20.8px;" /><br style="line-height: 20.8px;" /><span style="line-height: 20.8px;">So if I forget using an old HD, what would be safer?</span><br style="line-height: 20.8px;" /><br style="line-height: 20.8px;" /><span style="line-height: 20.8px;">1. A very low swappines (0) and swap partition (or file) on the SSD?</span><br style="line-height: 20.8px;" /><span style="line-height: 20.8px;">2. No swap at all and total relieance on the OOM killer if ever needed?</span><blockquote type="cite" cite="CAC73aR3QAYtq9UnBeB+NRKVWOfCA1AWoXa4wrHJe=NntCRTZ0Q@mail.gmail.com"><br />> 4. What about the rest of /var ? Better on the SSD (where log/ will cause<br />> writes) or on the media disk, where it will compete on a small way with<br />> access to the media files? On my old system /var/ excluding lib/mythtv was<br />> only a few hundred MB in size.<br /><br />...<br />...</blockquote><blockquote type="cite" cite="CAC73aR3QAYtq9UnBeB+NRKVWOfCA1AWoXa4wrHJe=NntCRTZ0Q@mail.gmail.com"><br />9 Power_On_Hours 0x0000 --- --- --- Old_age<br />Offline - 48721<br />209 Remaining_Lifetime_Perc 0x0000 --- --- --- Old_age<br />Offline - 98<br /><br />48K hours on, 98% life remaining.<br /><br />Eric</blockquote>Looks promising! Have you done anything to limit logging? tempfs or any other hacks to limit the impact on your SSD?<br /><br />BR.<br /><br />--Marius--<br /> </html>