<html><head></head><body>Ha! With HPC you START with a rack full of 48-core nodes with 2TB RAM each and 100 Gb ethernet backbone and then let users run "code they found on github" to make that gear look like a core2-duo swapping out to IDE drives.<br><br>Use what works. VMs are for systems that don't need dedicated hardware. Containers are for holding beer.<br><br>Coolest thing I've seen yet with VMs was live migration of a Postgresql system in mid-query to a second host. Added about 3 seconds to the query time but completed perfectly. Ovirt kicks butt!<br><br><div class="gmail_quote">On March 12, 2021 12:15:16 PM EST, DJ-Pfulio via Ale <ale@ale.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">On 3/12/21 11:47 AM, Tod Fassl via Ale wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"><br>Now, running your vm on someone else's cluster -- that I can<br>understand. But running your own? No, that's dumb.<br></blockquote><br>Not if your server has 24 cores and the DBMS only needs 2 to work <br>fast.<br>More cores and more RAM doesn't always translate to faster <br>results.<br><br>In a business, there is a trade off in having optimal use for HW.<br>If the DBMS is just 5% slower, but you can get 10 more systems <br>on the same HW for $0, that would be a huge win most places.<br><br>I see people with 16-core systems who decide to run a 16-core VM<br>with 32G of RAM because they can. Then we have them explain their<br>workload and suggest a 4 vCPU and 8GB RAM VM. Crazy, but it runs<br>faster.<br>With Linux, it is usually best to begin with 1-2 vCPUs and only <br>scale up when you know it is actually necessary.<hr>Ale mailing list<br>Ale@ale.org<br><a href="https://mail.ale.org/mailman/listinfo/ale">https://mail.ale.org/mailman/listinfo/ale</a><br>See JOBS, ANNOUNCE and SCHOOLS lists at<br><a href="http://mail.ale.org/mailman/listinfo">http://mail.ale.org/mailman/listinfo</a><br></pre></blockquote></div><br>-- <br>Computers amplify human error<br>Super computers are really cool</body></html>