--- title: Your Proxmox VMs don't need 8GB each and it's easy to... description: Over-allocating RAM to Proxmox VMs and LXCs can degrade host performance rather than improve it, since unused memory reserved by VMs is unavailable to the host... canonical: https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Your Proxmox VMs don't need 8GB each and it's easy to see how much RAM they actually use | daily.dev og:description: Over-allocating RAM to Proxmox VMs and LXCs can degrade host performance rather than improve it, since unused memory reserved by VMs is unavailable to the host... og:url: https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz og:image: https://api.daily.dev/og/posts/xPH0jH7JZ.png og:image:alt: Your Proxmox VMs don't need 8GB each and it's easy to see how much RAM they actually use og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Your Proxmox VMs don't need 8GB each and it's easy to see how much RAM they actually use **[XDA Developers](https://daily.dev/sources/xda-developers)** · 6 min read · 1 upvotes · 0 comments ## Summary Over-allocating RAM to Proxmox VMs and LXCs can degrade host performance rather than improve it, since unused memory reserved by VMs is unavailable to the host or other instances, potentially forcing costly swap usage. LXCs share resources dynamically with the host, but VMs reserve configured RAM outright. Proxmox offers features like Kernel Same-page Merging (KSM), which merges identical memory pages across VMs, and memory ballooning, which lets VMs dynamically reclaim and release RAM based on demand. The practical fix is to monitor actual RAM usage per instance and right-size allocations instead of over-provisioning by default. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why does allocating too much RAM to a Proxmox VM hurt performance instead of helping it? Unlike LXCs, which share host resources dynamically, Proxmox VMs reserve their configured RAM outright when started, making that memory unavailable to the host or other instances. If too much RAM gets locked up this way, the host can run low on memory and fall back to swap space, which is much slower than RAM and adds unnecessary wear to storage drives, degrading overall performance. _Anyone tuning a Proxmox home lab can track memory-management practices like these on daily.dev._ ### What does Kernel Same-page Merging (KSM) do in Proxmox? KSM consolidates identical memory pages held in RAM so that multiple VMs can share the same physical memory blocks instead of each holding duplicate copies. It is enabled by writing to /sys/kernel/mm/ksm/run, and scan rate can be tuned via pages_to_scan and sleep_millisecs, helping Proxmox hosts run more VMs on limited memory. _Home lab builders comparing memory-saving techniques can follow tool tips like this on daily.dev._ ### How much RAM does Immich or Home Assistant actually need when self-hosted on Proxmox? Real-world usage varies by workload: a self-hosted Immich instance assigned 12 GB of RAM was observed using around 10 GB, while a Home Assistant VM handling many devices and integrations needed about 8 GB to run comfortably. A lightweight PHP-based cron job app, by contrast, only needed around 512 MB RAM and one CPU core. _Self-hosters sizing VM resources for apps like Immich or Home Assistant can check real usage benchmarks on daily.dev._ ## Similar posts on daily.dev - [Proxmox has a ZFS setting nobody touches, and it could be starving your home lab of performance](https://daily.dev/posts/proxmox-has-a-zfs-setting-nobody-touches-and-it-could-be-starving-your-home-lab-of-performance-efp5ic0mn) · XDA Developers · 0 upvotes · 0 comments - [Linux containers do what my Proxmox VMs couldn't: run a dozen services without wasting half my memory](https://daily.dev/posts/linux-containers-do-what-my-proxmox-vms-couldn-t-run-a-dozen-services-without-wasting-half-my-memor-4f3lykuas) · XDA Developers · 2 upvotes · 1 comments - [I ditched VMs for Linux containers, and my home server finally has room to breathe](https://daily.dev/posts/i-ditched-vms-for-linux-containers-and-my-home-server-finally-has-room-to-breathe-v6uh40yts) · XDA Developers · 2 upvotes · 0 comments - [I always tweak my Proxmox host's settings before spinning up a single VM or LXC](https://daily.dev/posts/i-always-tweak-my-proxmox-host-s-settings-before-spinning-up-a-single-vm-or-lxc-j7bpwodpd) · XDA Developers · 0 upvotes · 0 comments - [I stopped throwing out old hardware after discovering Proxmox](https://daily.dev/posts/i-stopped-throwing-out-old-hardware-after-discovering-proxmox-ylxcz9qry) · XDA Developers · 0 upvotes · 0 comments --- Tags: [#linux](https://daily.dev/tags/linux), [#infrastructure](https://daily.dev/tags/infrastructure), [#homelab](https://daily.dev/tags/homelab), [#proxmox](https://daily.dev/tags/proxmox) [View this post on daily.dev](https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Your Proxmox VMs don't need 8GB each and it's easy to see how much RAM they actually use","url":"https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz"},"datePublished":"2026-08-30T13:04:41.843Z","dateModified":"2026-08-30T13:05:08.342Z","description":"Over-allocating RAM to Proxmox VMs and LXCs can degrade host performance rather than improve it, since unused memory reserved by VMs is unavailable to the host...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/6ddb56440f3b32a4db4beb7c85cdb020?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/6ddb56440f3b32a4db4beb7c85cdb020?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"XDA Developers","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"XDA Developers","logo":"https://media.daily.dev/image/upload/s--kCg6yyAP--/f_auto,q_auto/v1774964407/logos/xda-developers?_a=BAMAMiWQ0","url":"https://daily.dev/sources/xda-developers"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"linux,infrastructure,homelab,proxmox","timeRequired":"PT6M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"XDA Developers","item":"https://daily.dev/sources/xda-developers"},{"@type":"ListItem","position":3,"name":"Your Proxmox VMs don't need 8GB each and it's easy to see how much RAM they actually use"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/your-proxmox-vms-don-t-need-8gb-each-and-it-s-easy-to-see-how-much-ram-they-actually-use-xph0jh7jz#faq","mainEntity":[{"@type":"Question","name":"Why does allocating too much RAM to a Proxmox VM hurt performance instead of helping it?","acceptedAnswer":{"@type":"Answer","text":"Unlike LXCs, which share host resources dynamically, Proxmox VMs reserve their configured RAM outright when started, making that memory unavailable to the host or other instances. 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