A slight correction to the sar command line from my previous email. Sar will give you an average, if you want high resolution real time data, then run sar with a time argument, such as 'sar -B 5' for a report every 5 seconds.
On Fri, Jul 28, 2023 at 4:05 PM Keith Lofstrom <[email protected]> wrote: > Question about swap file vs swap partition. > > I have a dozen spinny disks with too many ancient > distros on too many machines. > > I am slowly consolidating to a few Debian 12 Bookworm > machines with Samsung terabyte SSDs. > > > When large-RAM low-power fast motherboards become cheap > enough, I will migrate to those. More RAM may imply > larger swap areas (a semi-religious debate I hope to > avoid). I want to be ready if the "large swap" zealots > win the debate and design software dependent on swap. > > SSD swap seems MUCH better than spinny-disk swap, > very fast access compared to moving a spinny disk head > across a platter ... though way slower than RAM. > > ---- > > Large SSD swap also facilitates fast hibernate, though > Debian startup and shutdown are amazingly fast using > an SSD (10 seconds startup/login, 2 second shutdown). > > Perhaps I don't need hibernate-to-swap. > > ---- > > One of my recent SSD experiments resulted in a too-small > swap partition. Inept resizing attempts borked the file > system. > > But ... I can also create a huge swap file on a regular > ext4 file system, and easily up-size the swap file when > I install more RAM. Resizing a partition is more complex. > > I've read some online debates about swap partitions vs. > swap files. Most of the debates are from the spinny disk > era; the speed tradeoffs have changed radically. > My main concern is reliability, software compatibility, > and ease of maintenance rather than maximum speed. > > ---- > > I suspect I will need SOME separate-partition swap, but > I hope I can get by with a few gigabytes, relying mostly > on a big swap file, growing that swap file over time as > I migrate to motherboards and laptops with more RAM. > > At 69.9 years of age, I should also minimize complexity, > deploying systems that I can maintain with an 80 or 90 > y.o. brain someday. My father-in-law is 105, and his > Windoze computer took many days to decrapify. I won't > have a son-in-law to do that for me. > > So, that's a lot of yammering, another sequela of excess > age. In summary: > > "Optimum SSD swap? ?? ???" > > Keith > > -- > Keith Lofstrom [email protected] >
