Proxmox zfs ram usage My problem is that proxmox gradually consumes all the RAM and then it freezes tightly. So I turned it off and with no VM running still had 18GB of memory usage. Heavy RAM usage and disk I/O inside the VM. Dec 24, 2020 · From the wiki: Limit ZFS Memory Usage ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. Now when I checked the zfs summary I see this Oct 20, 2024 · Pic. Swap usage is high too. May 16, 2020 · I installed my proxmox server on a two 250 gb ssd with raid1. The box has 64 gb memory. Mostly because I use ZFS, and have two Windows VM’s running with 48GB of RAM allocated each (plus 10 other VM/CT running with a few GB each). Htop from proxmox shows around 18 as expected. If you intend to use ZFS make sure to have enough RAM available for it. Now there is only a container Sep 11, 2021 · How to set up ZFS ARC size on Ubuntu/Debian Linux Explains how to set up ZFS ARC cache size on Ubuntu/Debian or any Linux distro and view ARC stats to control ZFS RAM memory usage. A lot of times though, when I need to weigh how much RAM headroom I have for adding Oct 4, 2022 · ZFS works best with a lot of memory. In Proxmox UI we can see 73 GB used in node RAM usage 58. Proxmox itself also uses RAM for caching, especially when ZFS is used. May 24, 2012 · Now why swap usage got to very high usage is something to debug and fix. Any advice? Dec 7, 2023 · The LXC, which just contains Caddy, uses around 50MB of RAM. 8. Whereas in the htop the used memory is around 3GB and 18GB in Proxmox summary (After turning off one VM Nov 7, 2020 · ZFS braucht RAM für metadaten deswegen ca. I have Mar 17, 2025 · Hi, I tried to answer a question with a link explaining Proxmox disk usage displays in the Web GUI, but I did not find a posting explaining it (possibly because I searched wrongly), so I decided to write a brief overview. Edit: I just found this. Proxmox is set-up to use ZFS and I've noticed that my system has been peaking the memory usage, even though individually the services don't even use 25%. Node1 free -mh: total used free shared buff/cache available Mem: 125Gi 57Gi 61Gi Dec 2, 2021 · That said, you can manually (and dynamically) cap ARC via the zfs_arc_max tunable. Jun 15, 2024 · Hi, every day after a backup of VMs usage of RAM on some nodes in my cluster increases (from 5GB to 9 GB per day). 7 Limit ZFS Memory Usage It is good to use at most 50 percent (which is the default) of the system memory for ZFS ARC to prevent per- formance shortage of the host. Does that percentage include the RAM used by ZFS? I am using ZFS on Proxmox itself, not in a container/VM. Nov 12, 2023 · If you don’t want zfs to use that much memory and are willing to accept the performance hit, you can set limits on the memory usage of zfs. proxmox. As I know ZFS consumes lots of ram, but what i dont get is how come the ram peaks when the servers are idle and when there actually working it drops, in theory should be the other way around. This speeds things up, but it will give up the ram if needed by the system. 2. htop)--Odd Readings (But Maybe Normal for ZFS?) Jul 13, 2024 · Hi pve users, I recently finished installing my services on the proxmox server running on zimaboard 432. My memory usage is constantly past 90% despite having a few containers and vms setup with about 30 gb usage between all of them. I dont understand why. Apr 14, 2022 · Hi, can also show your RAM usage and maybe give some more details such as how many VMs/CTs are running and how much memory they use? Also do you use zfs? Generally you could try to reduce "swappiness". 2 and kernel 6. If anything else allocates that RAM, ZFS gives up its cache. You can see in my dashboard that I only have 3 VMs running with a total RAM usage of 14. when I am caught up on projects we'll try removing extra swap on a test system etc. Jul 4, 2017 · Your ZFS is configured to use as much as half of your RAM (as indicated by the "Max size" line in the output you posted). The memory usage is always high, which seems to be normal with zfs. All drives are WD Red 4TB (WD40EFZX) Aug 31, 2022 · Hi everyone, I am new to Proxmox and I have been searching around on how to solve this issue. Mar 16, 2022 · Currently since I only have 2 of the 3 drives, I've been testing in a mirrored zfs config. Here a dozen tips to help resolve this problem. Jun 13, 2024 · Adding feature that will allow removal of existing zfs_arc_max line is up for discussion. Dec 15, 2015 · On my host machine. 80 GiB of 125. That's all they are assigned. Moreover, sometimes the Proxmox webUI status shows 15. Linux host (e. ARC won't be listed as "buff/cache" but as normal "used" but ZFS can shrink it dynamically but slowly from for example 64GB down to 1GB if needed by processes. Allocating enough memory for the ARC Oct 29, 2017 · Einen recht schönen guten Tag, ich habe gerade versucht den Ram den sich zfs "grabscht" zu begrenzen. How did you setup your TrueNAS vHDDs? Passthrough or local storage? What‘s not recommended is the usage of ZFS inside VMs on top of an existing ZFS dataset in Proxmox. Jan 31, 2021 · I didn't investigate that further yet. html#sysadmin_zfs_limit_memory_usage The procedure to make the change on temporary basis works perfectly and also as stated in the documentation a reboot resets the value. The server has 48G of ram. Starting from Proxmox v8. This pool is created just to create VMs/containers only and is used for local storage. I have learned that ZFS requires ECC memory, I have been using ZFS on Ubuntu server for a year now with standard DDR4. While this behavior helps speed up disk reads, it can consume a large portion of available memory if not configured correctly, especially on systems with limited RAM. Jan 13, 2020 · RAM usage seems to be as much RAM allocated to VM on main server. I've also noticed ZFS & RAM Usage My server has 24Gb of RAM. For my other Proxmox server, with 128GB of RAM, without a conf file, my arcstat is using 12-13GB RAM. The utilization of zfs cache is very low only 458G out of 1. 4-3-pve. Could caching be causing this? I shutdown the VMs and 10GB of RAM was in use just for Proxmox. You have assigned 24GB (16 + 8) to your VMs. Currently using 8 x 1. Proxmox shows 7% usage at the moment. 4) I have several VMs running on Dec 15, 2022 · Hi, I don't know why my proxmox host in cluster have most memory used I just have 3 virtual machine: First PVE: 1 = 6Gb 2 = 4 Gb 3 = 8 Gb Total = 18Gb and usage summary page show on this host = 22. 2-1 on it using ZFS. Aug 6, 2019 · KSM (Kernel Same-page Merging) is a great tool for getting a little more out of your precious RAM, it’s enabled by default in Proxmox, but the default settings are not ideal for use on a ZFS system where RAM usage can spike wildly the first time a disk-heavy operation takes place (e. I am having to do this daily Oct 25, 2023 · Which 'this' do you want to mitigate? I can think of a few more or less useful mitigations for "using ZFS with this amount of storage and this amount of RAM is slower than I have patience for" Add more RAM, or Buy smaller disks, or Use another file system all together, or Exercise more patience One does not exclude the other. Right now I'm running proxmox 5. ZFS Ram usage So, I had to migrate my ceph pool to a zfs (raidz2) pool and I'm noticing huge ram utilization. I am running Proxmox 8. 0 or later) of the system RAM but you can reconfigure it in /etc/modprobe. conf file. When I first build the mirror, RAM usage sits at about 1. Oct 1, 2020 · Hi RockNLol I‘m quite new to Proxmox and ZFS, but I‘ve read somewhere that running out of memory could be related to the RAM usage for ZFS. I'm reviewing the memory usage under Summary and it's stating it's using 40gb, but the VM's are only using 18gb. Jul 17, 2024 · Businezz Thread Jan 2, 2024 memory memory issues memory usage ram ram utilization Replies: 3 Forum: Proxmox VE: Installation and configuration S Jan 16, 2025 · Hi, Proxmox was showing high memory usage with only one OS running (Cockpit which has only 1GB of memory allocated). It return to normal usage. On this machine, I have three VMs: - Windows #1 with 4 GB - Windows #2 with 4 GB - Linux with 256 MB Ballooning is enabled, but I did set fixed RAM limits Dec 6, 2021 · since version 8. By default it uses half of RAM. 3GB). 1. Linux and especially ZFS use all unavailable RAM as cache. It sounds like a proxmox VM thing. ZFS uses the memory for caching and would free it if an application would need memory Oct 23, 2022 · Hi Guys, I recently installed proxmox on my old PC with 2GB Ram. Sep 19, 2018 · Hi guys, I am just starting out with Proxmox / LXC / ZFS. 15GB + VM-2 7. I created a ZFS pool composed off 5 x 800GB enterprise SSDs in a `raidz` configuration. For new installations starting with Proxmox VE 8. The server has 64GB RAM and there is one virtual machine with 16GB RAM (Windows Server 2019). How do you determine actual ram usage on ZFS under linux? Linux standard system monitoring tools don't take into account the ARC cache, so reported available ram is going to be much lower than the actual number. But then, i saw this in my monitoring: Yes, the point where the usage of the huge amount of Cached and Shared started, was exactly the moment, when i enabled the VirtioFS. So, according to my calculations, the total RAM usage should be around 11GB (Proxmox 1. Limit ZFS Memory Usage ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. The host uses more than 95% memory usage and then swaps heavily which causes ZFS Apr 10, 2021 · Proxmox is a great open source alternative to VMware ESXi. It started to happen after upgrade to Proxmox VE 8. Server hardware: 16 core AMD Ryzen 5950x, 128GB RAM, 2x 1TB NVME SSD combined in ZFS 1TB pool. Specifically, ZFS uses the ARC (Adaptive Replacement Cache) to store frequently accessed data in memory. 1 fresh install has a ZFS memory fix that limits the memory usuage to 10% of the system memory. I'm unable to account for an extra 2GB of usage. I built a new server and installed Proxmox 7. . If you upgrade Proxmox then you will need to manually create the zfs. Jun 7, 2022 · My proxmox 7 is showing very high ram usage when idle. To view how much memory the ARC is currently using, you can run the arcstat command as root on your host system. 5 gb. 37GB. My understanding of ZFS is that it fills as much RAM as it can. Apr 20, 2021 · Can anyone clarify the procedure to set the memory limit for ZFS? This is the link to the instructions below: https://pve. Jun 12, 2025 · Immich High CPU and Swap Usage, Cannot Reach Web UI Hi, all. However, according to the stats page of VM 100, 101, and 105, the usage totals to about 8GB. In physical server ZFS uses only RAM what is not needed for other applications. 5GB, 2GB, 2GB, and 12GB of RAM, for a total of 17. This isn't always instant though, so if you start hitting 80% - 90% ram use then it may be worth you setting the max arc cache size to something like 64GB. I’ve got two Ubuntu VMs running. Also, I'm noticing that the ram util is different on htop and free -m Is that an exptected behavior ? Oct 3, 2024 · Hi, Proxmox was showing high memory usage with only one OS running (Cockpit which has only 1GB of memory allocated). Has anyone else seen swap usage very high? Jun 27, 2020 · Hi all have you seen this issue? I am running A Lenovo SR530 server: pve 8. A look into htop proofs it - more than 49 GiB of virtual memory. 2 with a 2 HD mirror using ZFS for root I'm following this instruction Nov 27, 2023 · Hi. I Dec 24, 2023 · Hi everyone, i'm having issues with abnormally high RAM usage from boot. 17 GiB Second PVE: 1 = 1Gb 2 = 2Gb 3 = 2Gb Total = 5 GB and usage summary page show on The problem is that it doesn't. It happenes until node crashes. Deployed Home Assistant and Plex so far, and figured out kernel updates, GPU passthrough, and external networking. I boot it of off a single SSD. From the man page: zfs_arc_max can be changed dynamically with some caveats. You can check with commande arc_summary -s arc is your TrueNAS VM use the not recommended ZFS over ZFS ? or do you passthrough a HBA ? In this video I'll show you how I reduced my Proxmox RAM usage by switching from ZFS to NFS on my Proxmox homelab. Feb 15, 2024 · Hello everyone, I'm facing an issue with understanding SWAP usage on my system and could really use some help from the community to clarify things. What's causing the high ram usage and is this normal? I originally had it at 8gb and increased it to 16 thinking that 8gb wasn't enough, but it doesn't matter Jun 25, 2025 · Explains how to set up ZFS ARC cache size on Ubuntu/Debian or any Linux distro and view ARC stats to control ZFS RAM memory usage. This is our offsite backup that doesn't get bombarded with writes from PVE's. Nov 16, 2020 · Hello everyone, after following the posts and the official guide on how to limit the ZFS cache (arcstat), I was asking for your opinion regarding the configuration of my cluster. Eventually the system becomes unresponsive May 11, 2022 · Hi, In a home lab environment, I have a server with 256GB RAM, a dozen VM's on it and a ZFS pool also in the same box. Of course, this kind of memory should be normally available for other Jun 21, 2024 · Hi all. My server has 32GB of total memory and i'm autostarting 4 lxcs with about 2. (Proxmox 6. Anyone know why? Aug 31, 2022 · I posted a question regarding ZFS memory usage and you guys pointed me to the right place to change how much memory the host system uses for ZFS. But here cgroup see memory usage in container Jul 5, 2017 · Hello! We bought a new backup server last year. Here are some more info: May 27, 2015 · 5 node cluster, each node with: Intel Xeon E-2288G 128GB RAM 2 x 1,92 TB NVMe SSD in ZFS Mirror Replication of VMs between nodes via ZFS-Replication And the question is: Considering the speed of NVMe, how much RAM do we need to reserve for ZFS to make sure it works properly and does not cause unexpected reboots? Jun 23, 2022 · Thank you in advance for any help. You should only get minimal swap usage but it will be enough to prevent the OOM's. You can try to Nov 18, 2022 · The ram usage display in the host is like all vm use 100% of their ram, but, when i go to the vm summary, it's display the right memory use by windows (corresponding perfectly with what's is given in windows task manager). As an example: VM1 (ext4 filesystem) - Allocated 6 GB RAM in Proxmox, it is using 3 GB for applications and 3GB for caching Host (ZFS filesystem) - web GUI shows 12GB/16GB being used (8GB is actally used, 4GB is for ZFS ARC, which is the limit I already lowered it to) Jan 21, 2025 · Hi, I have 2 proxmox hosts each with local zfs with draid2 with 8 sas disks, 2 sas ssd nvme for zfs cache and other 2 sas ssd nvme for zfs log. Kinda bad because proxmox promotes ZFS so the WebGUI should in my opinion show better statistics around RAM usage in the summary page. Aug 13, 2017 · Hi, I was wondering if someone could shed some light on the issue im having with the ram. Do you ZFS, by default uses 50% of available ram for arc cache. One for Pihole/Pi VPN and the other for Jellyfin. 1, theARC usage limit will be set to 10 % of the installed physical memory, clamped to a maximum of 16 GiB. Proxmox is a popular open-source virtualization platform that supports a variety I made sure that qemu-guest-agent is enabled in Proxmox, and os-qemu-guest-agent is installed & running in OPNsense. Hey everyone, Proxmox has been using a very high amount of RAM (close to double) with only a small amount of VMs running. Server A RAM usage Oct 9, 2024 · ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. How can I determine the current size as well as size boundaries of the ZFS ARC May 1, 2025 · So imho a normal setup with disabled cache, as the caching is already done by ZFS ARC. ZFS will however always yield ARC memory to other processes if needed, so the ARC should never lead to out-of-memory situations. However, if you spin up a new Proxmox hypervisor you may find that your VM's lock up under heavy IO load to your ZFS storage subsystem. that's crazy. d/zfs. I know that ZFS use from 4 to 8GB of RAM, but the problem is that much more ram missing and I May 24, 2020 · Helloooo :) I have proxmox installation with zfs on 32gb ram i7 and raid 10 conf. Now Immich has me stumped. Dec 13, 2018 · Is there a command or two that illustrates where RAM is being consumed on our Proxmox systems that are using ZFS? For example, here is the RAM usage on a new system: Feb 12, 2021 · Hello, We are have two Dell Servers and they are running Proxmox v7. Dec 20, 2024 · ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. Ultimately, the host killed the virtual machine process to retrieve RAM and prevent an outage. You can try to Mar 1, 2018 · You have no swap, even with bundles of ram, on proxmox you can get OOM's due to memory fragmentation, disable transparent huge pages and add some swap. Jul 10, 2024 · Proxmox 8. And it doesn't return to normal usage after backup has been completed. I have the memory set to 16GiB with 12GiB as the minimum, ballooning is also enabled. Apparently the RAM usage dropped a ton after a restart. 4. conf Beginning with ProxmoxVE 8. I have that ZFS volume shared to Aug 21, 2025 · I posted a question regarding ZFS memory usage and you guys pointed me to the right place to change how much memory the host system uses for ZFS. 3-4 machine that runs on the (default) ZFS setup. I am aware that ZFS seems to use double that, so I expect 64GB RAM used, however I am currently sitting at 122GB out of 187. The hypervisor itself is installed on two nvme disks, 256 GB each, in the ZFS mirror. Mar 12, 2024 · For new installations starting with Proxmox VE 8. By default, the memory usage is limited to half the amount of installed RAM, in your case 16GB. Dec 5, 2017 · The ZFS ARC is already limited to 10% min and 30% max of all memory on the server. My vms are stored on another zfs storage pool. First of all, I thought it was caused by Apr 8, 2022 · I have a proxmox node that is reporting the used ram way higher than the summed assigned ram of the working VMS the above is reporting around 116G of ram used, but I only have the following VMs running if we took the sum of all reported VMS RAM usage, it will account to 36G and the Apr 24, 2023 · I have docker setup in a VM on a ZFS volume and the summary reports high ram usage, but free -h reports only 1gb of ram is being used. What can I do ? Thanks! In my cases: On my primary file server that holds only one VM (pbs), all but 32 of 512G is available for ZFS. Aug 6, 2019 · I have 62. They have assinged in total 28G of ram. com/pve-docs/pve-admin-guide. When my "not test CTs" work with files, they use all RAM and after some time i have a lot of errors about memory limits and about kills of processes. Der Hintergrund: Ich habe 64GB Ram in meinem Server stecken. I have that ZFS volume shared to Feb 27, 2023 · ZFS is pretty memory hungry. As i think, ZFS "eats" memory for cache and this memory is calculates to container but not to node. 3. 1GB RAM je 1TB Speicher, auch wenn dieser nicht belegt ist. The problem is that it doesn't. Allocating enough memory for the ARC is crucial for IO performance, so reduce it with caution. I've read a little bit and some people might be mentioning the slab might be taking it all for ZFS but even with the slub_nomerge kernel parameter the problem persist. I have tried Proxmox before and loved it, however this time I have a different setup! Server specs: 16 GB RAM (DDR4) 2x 450GB NVME SSD (ZFS Mirror) Intel Xeon E3-1230v6 - 4c/8t - 3. 2 TB SAS drives for the zfs pool and my ram consumption is 221GB used out of 384 for a ~9TB pool. As far as I understand, SWAP is supposed to store less frequently accessed data to free up RAM. Now I'm at a steady idle 53. I'm new to Proxmox for my homelab, and appreciate all the great posts here. The disk I/O inside the VM caused the ZFS ARC cache to grow without bounds. 4 - RAM usage parameters in console of `zfs` with command `arcstat` ------------------------------------------------------------------------------------------ Jun 1, 2014 · Hello, we're facing serious issues with Proxmox since upgrading to PVE 5. 5GHz I am only using one empty LXC container at the Jan 27, 2017 · Hi, I installed Proxmox 4 with raid 1 in ZFS We have just 7 VMs (4 Linux on Centos7 and 3 Windows) with 20 G total in all of them. For example in case you re using ZFS then by default up to 50% of your RAM will be used by ZFS as its ARC for caching. You can check the status and you can change this default, Google it. If you’re really pushing high memory pressure, you’ll see the ARC usage go down. This Procedure is described in the Proxmox Documentation for ZFS. Jan 16, 2024 · 192GB RAM 2 x 4TB NVME, On it, I have 3 VMs 1 x Windows VM, allocated 8 cores, 16GB RAM 2 x Debian VM, allocated 4 cores, 8GB RAM The total RAM across all VMs is 32GB. It's a backup of the backup with longer retention Jul 16, 2025 · Taking a detour from the RAM consumption shenanigans on VMs, I wanted to go over an anecdote from my early days of Proxmox. should really only be added/enabled in ZFS if you know your workloads need it and can benefit from it. swappiness=10 command. On my servers with local storage, 32G to ZFS and the rest for VMs. Oct 17, 2022 · TL;DR: RAM cache pros/cons, and how to? Or SSD cache pros/cons, and how to? Optimal choice? I don’t understand how to get more out of my array, and maybe someone can help me here, or point me in the right direction. As storage we use CEPH. Manually any amount of cache can be set. What's using the rest? I migrated these machines from another node that has essentially the same hardware but was not ZFS, and the RAM usage was as expected. As a general rule of thumb, allocate at least 2 GiB Base + 1 GiB/TiB-Storage. The OS and VM/CTs are all in a 2TB SSD drive. 1 , pve set ZFS "ARC" to 10% of RAM , so it shoud be set to 6 GB. So dachte ich mir, da müssten Nov 18, 2024 · Real RAM usage is often „blurred“ by caching which is pretty normal for nearly every virtualized OS. How do you calculate the ram actually used? Subtract kstat/zfs/arcstats from the "used" figure in free ? Sep 12, 2022 · Understanding RAM Usage Statistics in PVE web UI vs. The third point would be the most serious suggestion. Mar 14, 2015 · High RAM usage is therefore completely normal if you use ZFS and isn't something you need to worry about - but if the ARC is underutilized, you won't get many of ZFS's speedy benefits. com/wiki/ZFS_on_Linux#sysadmin_zfs_limit_memory_usage Jan 19, 2025 · When setting up and managing servers, one of the most common areas of concern is memory usage. This value is written to /etc/modprobe. Auf dem System sind ca 10GB Zfs Speicher. If the host needs more than 8GB RAM for ZFS, then it will probably run out of RAM for the VMs. The first node has 32GB of physical memory, and disks including the operating system in ZFS, a 1TB ZFS disk. ZFS is great Mar 2, 2017 · Since there are many members here that have quite some experience and knowledge with ZFS, not the only that I`m trying to find the best/optimal setup for my ZFS setup; but also want to have some tests and information in 1 place rather than scattered around in different threads, posts and May 18, 2018 · RAM at 90+% doesn't mean you have to be out of RAM. Aaaahh, you're May 14, 2023 · I have a 64GB RAM system with 16TB in a RAID HHD storage, so with 8TB used. htop)--Odd Readings (But Maybe Normal for ZFS?) Jul 31, 2024 · Proxmox ZFS cache reduce to free-up RAM As mostly we do not use ZFS on Proxmox, except system volumes, ARC just wastes LOTS (50%) of RAM, also we cannot see real RAM usage by VM on hosts. 5700G 32GB RAM I have 10GB ram assigned in total so far but the dashboard on Proxmox shows the full 32GB in use most of the time. Mar 25, 2022 · By default ZFS will use up to 50% of your hosts RAM for the ARC (read caching). 2. For Proxmox users, this often revolves around understanding the intricacies of memory Dec 20, 2024 · ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. 1 20 x Intel (R) Xeon (R) Silver 4210 CPU @ 2. a backup or clone from one zpool to another). I need help with a memory leak that I'm experiencing. Whereas in the htop the used memory is around 3GB and 18GB in Proxmox summary (After turning off one VM Oct 21, 2016 · ZFS uses an ARC (adaptive replacement cache) which is not accounted for in the traditional Linux "cache" memory usage. 1, new installations of Proxmox apply limit on ZFS cache ARC size to 10% of total RAM amount, also 16GB limit. 66% (73. Most likely after some proxmox update in May/June I started to experience random VM restarts which I concluded were due to a high RAM usage because since about June I can see the RAM usage as 92-96% = 82 to 84 GB out of 86 GB. What is the remaining memory being occupied by? Jun 15, 2020 · Hello, How to calculate optimized for zfs cache, it uses too much memory and I don't have space to create MVs. It’s a commons approach and can be observed on all modern systems and is used to speed up access to regularly used files or in ZFS‘s case access to meta data. Unless you have a VM passing through freenas or something. Bei dir würde ich mit 3-4gb anfangen, da du nur 32GB RAM hast. With vps on I have 60% ram usage, but when I power off all machines , the ram usage go down only to 50% And only if I reboot. I see more than 5G of swap are used. Jun 30, 2020 · hey guys is there anyone who can pls explain to me what is this that is using so much ram of server and how can i fix it ? Jul 11, 2025 · Memory never exceeds the use 132GB of the available 256GB according to the history graph I now increased GC cache capacity to 8388608 ZFS mirroring would indeed be ideal. Also, stuff like a SLOG, L2ARC, Deduplication, etc. Du musst arc begrenzen ansonsten nimmt zfs standardmäßig 50% vom RAM. ZFS is a wonderful alternative to expensive hardware RAID solutions, and is flexible and reliable. Have you checked the VM under load to see how much mem it actually uses. conf Jun 15, 2020 · VM has 8GB ram, but after backup the VM eats almost 50GB ram (and I think it still keeps growing). Their is a small mention of this on the Proxmox Wiki - ZFS_on_Linux - sysadmin_zfs_limit_memory_usage For my GTR7 Pro system with 96 GB of RAM using 2 x 2 TB 990 Samsung Pro drives: /etc/modprobe. I've read that ZFS actually requires a lot of RAM Oct 22, 2020 · ZFS works best with a lot of memory. But htop 3gb using. 6GB/16GB. Feb 14, 2025 · ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. Could you please let me know if it is normal for the Replication in Proxmox? If yes, why it shows high memory usage? Thanks. Du kannst auch darunter gehen, kommt dann aber zu performance einbußen. My Proxmox server consistently shows very high SWAP usage, nearly 100%, after running for several days. For How to limit / Calculate usage memory must read the following section on the link. For ZFS storage, I have just 1 zpool - 2 1 TB SSD's in RAID 1, so it didn't feel necessary to use that much RAM. 99 GB RAM usage. 83 GiB of total RAM according to the Proxmox Web GUI, which leaves me approximately 30 GiB of maximum RAM available to safely use for VM allocation, but I was able to increase that to almost 54 GiB of RAM by tuning the ARC. Apr 27, 2014 · Freshly installed Proxmox 4. How is the Disk-Usage calculated on ZFS with RAID1 on two 465 GB disks? On the overview screen i see: Storage Nov 18, 2022 · The ram usage display in the host is like all vm use 100% of their ram, but, when i go to the vm summary, it's display the right memory use by windows (corresponding perfectly with what's is given in windows task manager). May 13, 2024 · ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. I have a RAIDZ2 setup on 2 vdevs 6x4TB. It is equipped with 32 GB of RAM and 512 GB + 1 TB disk space. Essentially what I'm seeing is the memory usage gradually increasing over several days until it utilizes nearly 100% of RAM, fills up the swap, and then oom-killer begins killing processes. ZFS arc is configured to 2GB as per: options zfs zfs_arc_max=2147483648 and is verified by issuing root@neuromancer:~# I have one server in my cluster running at 95% RAM usage (180GB out of 189GB, although it actually has 192GB of RAM). A good calculation is 4GB plus 1GB RAM for each TB RAW disk space. This will make the kernel use swap space less aggressively. Apr 19, 2024 · Limit ZFS Memory Usage ZFS uses 50 % of the host memory for the A daptive R eplacement C ache (ARC) by default. ZFS uses up 50% of the host memory for its performance and for the Adaptive Replacement Cache (ARC) by default. 1-43 on a "new" dell R630 server. Is this Re: Swap memory usage is too high by Moogle Stiltzkin » Fri Jul 17, 2020 9:22 am whenever you visit resource monitor and you get a swap memory alert, it means that your nas Hi, Proxmox was showing high memory usage with only one OS Jun 30, 2010 · Hi, I have a little project with 3 nodes 64GB ram each I use gluster on top ZFS as network filesystem on dedicated Nic's at 10GB ad another 10GB for corosynch (plus a third 10GB for internet access). The installation is on two mirrored SATA disks with ZFS. 89GB used in the VM Summary tab, which is really Nov 4, 2020 · But when I look on the HOST summary RAM usage is always at 90% + (58 Gig of RAM) (CPU is very minimal, and total space is very low too with 1 ZFS rppol that is only used at 50%) I’ve just started using Proxmox. But the memory usage is high. If you dig into the htop settings, you can also add a readout for ZFS Arc directly, which will indicate the total size of the ARC and how much is being used. The minimum memory across my Proxmox systems is 128G for a system used for off-line backups to a ZFS rust pool. Aug 19, 2016 · I know there's an open topic about zfs that was killing servers for using to much ram. I try to explain simple, even if sometimes not 100% accurate If it was zfs it would show the usage under proxmox itself. this file is generated during system install and will limit the ARC usage to 10% of your installed By default, the Ram bar at the top will show actual memory in green, and cached ram (ZFS) in yellow. 5TB. I was found Dec 16, 2017 · The RAM usage was always like 75 % for many years with the same VM running all the time. I understand that there will always be overhead with environments like this. 3 which is used in PVE 9. I ordered an Epyc 7402 and Supermicro H12SSL-i, I will buy ECC memory now that I Jan 1, 2022 · Hi, I have a 3-node cluster with identical nodes, but zfs is using up much different ram on different nodes: Node: 128RAM, 2x500GB ssd's for PVE OS. 5Gb of total ram use. As soon as I build a windows 11 VM with 4gb on the array, the ram usage of the server spikes up to near 20gb used. Proxmox web console show 47gb used. May 24, 2024 · For new installations starting with Proxmox VE 8. According to Proxmox, OPNsense is using up about 14GiB/16GiB, but Proxmox reports that the RAM usage is just 2. I didn't install any VM/CT and I am not using ZFS, the initial ram usage is a little over 1GB, Is there a way I can reduce this much RAM usage to something like 500MB? Aug 21, 2025 · I posted a question regarding ZFS memory usage and you guys pointed me to the right place to change how much memory the host system uses for ZFS. Aug 3, 2025 · If I remember it correctly, the rule of thumb says: 1TB of storage equals to 1GB of RAM usage for ZFS based system I have on server with 32 GB of RAM and mentioned above drive installed Proxmox 8 with 3x ZFS is known for its memory usage, as it leverages RAM for caching to improve performance. 89 - 53. Davon hat Proxmox nach dem Start bereits um die 30GB belegt. g. Also note, that evaluated cache size is calculated strictly by formula, based on sum of zfs storage pools, when recommended cache size takes in account minimum recommended amount of 8GB ram. conf. 2 with replication. 4, on a NUC n150 with 8gb RAM. 1, the ARC usage limit will be set to 10 % of the installed physical memory, clamped to a maximum of 16 GiB. Since I have the version with 4GB of soldered RAM, the memory runs out immediately, at the moment I only use four containers which Jul 31, 2024 · Proxmox ZFS cache reduce to free-up RAM As mostly we do not use ZFS on Proxmox, except system volumes, ARC just wastes LOTS (50%) of RAM, also we cannot see real RAM usage by VM on hosts. 0 or later and PBS (ProxmoxBackupServer) 4. But the Jan 23, 2010 · Proxmox WebGUI only shows total RAM usage without any insight on what is using the memory. To this Nov 22, 2022 · Hi all, When using zfs pool for primary storage in pve, it uses nearly total ram for ARC service I cant predict how much ram left for me, separating ram usage from services that relative to zfs and VM ram usages can solve this problem Thanks Feb 2, 2022 · Hi Misinthe! As Dunuin already pointed out, the ARC (or Adaptive Replacement Cache) of ZFS might use up to half of your totally available RAM on your machine as per the default settings of ZFS. There are circumstances in which you want to limit the amount of memory ZFS is allowed to use. Could also verify guest agent is running too. 5GB. I have that ZFS volume shared to my Plex VM using an NFS share. This is a new installation, I hardly even use any containers or virtual machines yet. May 7, 2025 · Normally ZFS would use around 50% ( changed to 90% with ZFS 2. 5GB RAM usage, so I'm unsure what's using the leftover 3/4GB Nov 21, 2018 · Hi, I have a single PVE 7. So after one day (since a reboot) the memory usage of Apr 6, 2025 · When I start my computer, the htop command shows a very high RAM usage, even without having started the web browser, which is a very common resource eater. However, be sure to understand that simply reducing it below current ARC usage will not immediately release memory. 20GHz (1 Socket) RAM: 192 GB I am not using memory balooning for my Vms i have 10 Vms with 8Gb each = total 80Gb 1 Vm with 4Gb TOTAL allocated memory: 84Gb my Host show usage of almost double that ! is there any Memory leak? my server firmware update to the latest firmware options zfs zfs_flags=0x10 Because I don't use ECC RAM. The file system is ZFS. Oct 25, 2020 · My 64GB RAM machine with ZFS seems to stabilise at 80% memory usage all the time for the root proxmox host. Is ProxMox not able to show the real RAM usage on Windows VMs? The VM tells me it's using 8 GB, ProxMox tells me it's using the complete allocated 32 GB. I have 3 MV of 1 Gb of memory each and 32 Gb in the host and it uses 80% of the memory. 5GB + VM-1 2. The issue: RAM usage is constantly increasing even though there are not that many VMs, and the VMs are not using any more RAM than normal. As a member of the ZFS faction, it didn’t take long for me to create The new ZFS node has 32GB of RAM and only 4 VMs that use 1. The RAM usage chart on the node summary page shows the total RAM usage, which makes sense. Aug 14, 2017 · I got two Questions: 1. You could limit the ARC size like for example described here: https://pve. We chose to go another route to increase available space while still having some redundancy. You can do this with the sysctl -w vm. You could always adjust the Max memory. Only 3 guests are running. However, the Summary page of the node shows 95% memory usage: RAM usage at almost 30GB when VMs only set to consume 18. The both server has 64Gb RAM. 81 GiB) You can recommend best way for tuning the Zfs memory with Proxmox? I Nov 29, 2024 · Is it possable to configure or at least reasonable to want the proxmox web interface to subtract the ARC cache from RAM usage in the web interface, and leave viewing statistics with ARC consumption for another graph or the arcstat and other commands. Ok, so now on to the help. Feb 13, 2021 · Hi All, I have a server with `192G` RAM. 20GB of RAM were allocated to the single VM, which left only ~2GB for the host and ZFS.