Unraid raw vs qcow2 Oct 9, 2015 · It seems that the unRAID VM Manager GUI only allows for 'raw' and 'qcow2' disk image types. Default Variables: You can leave all other settings as default. Option for btrfs will be added at a future date. 5. VDisk Type: Choose the vdisk type: Raw or QCOW2. Qcow2: Choosing the right virtual machine disk image format for speed, storage efficiency, and snapshots. There are two options at present qemu which creates a qcow2 overlay and zfs filesystem. I'm a bit unclear if I ought to just partition the drive as zfs and then set up the later vms on top of that or if I should leave blank space for raw vms. Jul 21, 2020 · 在新装的服务器上，用的操作系统是 Proxmox Ve，然后上面有不少的虚拟机 VMs，原来的虚拟机磁盘一直是 raw 格式的，最近新增加的两个虚拟机确实默认用了 qcow2 的格式。 May 15, 2023 · I do know that RAW is only available because that's a block level image that runs on top of ZFS natively. vm qcow2image. For one thing, I think we can finally put to bed the trope that zvols are faster than images. Could not get it to Sep 18, 2013 · I wanted to test our qcow2 versus raw image format performance, so I created two virtual machines on my hypervisor, below are the results I encountered. Nov 12, 2020 · So I read some articles and tutorials in order to create a Windows gaming VM with UnRAID. Unraid uses libvirt for VMs, which afaik only supports raw and qcow2 formats for disk images. 3-2 is configured for my vms to run on a local SSD. I wanted to test the snapshot feature, but I receive an error, "The current guest configuration does not support taking new snapshots" I found I can use the "Move Disk" Sep 6, 2015 · A qcow2 relies on mechanisms other than sparse allocation to achieve "thin provisioning" and is thus easier to move around. This comprehensive guide highlights the strengths and use cases of each format, providing detailed reasons for their preferences. The VM did not boot, just got stuck in UEFI prompt. Hypervisor: CentOS 6. While QCow2 images support snapshots, they can degrade performance even further. img to cache drive. I have the SSD setup as an LVM. File-backed IO, rather than QCOW2 specifically. RAW vs QCow2 The format of the data also makes quite a difference. Running the Dec 4, 2024 · 应该是刚刚在 webui 中修改了 qcow2 的路径导致 UNRAID 错误得将 type='raw' 写到了 xml 里. Feb 15, 2022 · ZVOLs are much faster than QCOW2 except for 4k IO at tiny queue depths. Thus, lets understand what they are and their differences. After spending too much time over the weekend testing GUI options for KVM management with unRAID and being disappointed, I learnt that it's super easy using SSH if you have configured your VM correctly. Jun 29, 2020 · I am finally getting my system back up and running, and now trying to move a Windows10 VM from Proxmox over to Unraid. 1 (Q35 still has the poor performance as well). I'm just not sure what steps I need to take to use . com/home-assistant/operating-system/releases/ and get the latest ova qcow2 im… May 18, 2018 · Overhead is much lower as well. Sep 12, 2018 · So the question IMHO is never "raw file vs qcow2 file", it is "qcow2 for features, or some pass-through for speed" - raw files are somewhere in between and rarely useful for either of above trade-off decision. Step 1: Get qcow2 image Go to https://github. Feb 5, 2021 · This is in fact exactly the problem. 4 with KVM Processor:In… Sep 14, 2011 · Hello, I am planning on virtualizing Debian Squeeze guests on a Debian Squeeze host. 6. Interesting. What exactly is the difference between qcow2 and raw disk formats? But exists some tips that can be used. it works fine with KVM on Debian. VDisk Size: Specify the size for the macOS vdisk in gigabytes. From what I remember (had an earlier system crash issue), I had converted the Proxmox image over to qcow2, and have that file. First disable copy-on-write on the volumes or directories where you store your image files, second use pre-allocated files for the images of VMs when using qcow2 file format and last use raw format for VMs that need high write performance (in my case SQL Servers datafiles). Default is qemu. CPU and GPU passthrough are working great and also a UnRAID share is passed to the VM. That's the second interesting thing: why did fio show abnormally high 1MB reads for zvols vs everything else, when iozone and the other tools did not? 1MB read VM setup Setting up a VM on Unraid is a flexible way to run full operating systems - such as Windows, Linux, or other platforms - alongside your containers and native apps. Moved the . vm convertedraw. Learn how to convert between VMDK and QCOW2 with a step-by-step tutorial for Debian systems, and discover which format best suits your virtualization needs. The default option is Raw. 0-beta30) in VM Engine (KVM) November 12, 2020 To backup a qcow2, you have to quisece the filesystem (if it's running and qemu-guest-agent is running on the guest) and convert it to raw. Oct 9, 2021 · Hi. Qcow2 which one is better in virtual machines? focusing on performance, security, and storage efficiency for better data management. RAW images are considerably faster than QCow2 images, which are libvirt’s default on most distributions. For best performance using a raw image file, use the following command to create the file and preallocate the disk space: Jan 19, 2021 · The video version of this tutorial can be found here: install Home Assistant as a VM on Unraid. To begin with, one of the important part of virtualization is storage. qcow2 supports snapshots and thin provisioning which raw does not. # qemu-img convert -O qcow2 convertedraw. Explore both options in this quick guide. Yeah I agree, on my other server in the office we have an nvme drive and it's so fast the raw vs qcow2 difference is imperceptible. Snapshot is not a backup of the wh May 15, 2016 · Does anyone know of a tool installed on unRaid that will clone a VM? I am new to KVM, but I am used to cloning VMs on esxi via the command line. The two major disk image formats, widely recommended and used are raw and qcow2. It can be converted in many formats, if needed. Vmdk is a VMware format that's generally only used by VMware workstation or esxi. Whether you want to test new software, run legacy applications, host a desktop environment, or utilize hardware passthrough for gaming or creative work, Unraid's VM Manager makes the process approachable for all skill levels. metadata). The motherboard is an X79 chipset and the VM is running 1440fx-5. As you went with ext4 with hw raid i would only go with qcow2. 9. It is a question of compatibility and convenience vs sheer power and stability, but imo, in this case, the gains with raw are far from compensating the losses in the other chapters, but to each their own. I have read a few suggestions of just copying the . Through some go Feb 4, 2025 · - What IS the actual performance difference of RAW on ZFS block devices vs QCOW2 on a ZFS/Directory setup? I've heard some say it's awful, others indicate it's only slightly less. 2 BIOS: SeaBIOS (OVMF cannot create snapshots when the VM is running. I think the flexibility you get with them being thin provisioned makes more sense than passing through a static drive that I can't use in my array. You cannot use vmdk files directly but you can convert them. 3. In my XML, I also had `type=raw` which when changed back to `qcow2` yielded a successful startup. The only results where zvols significantly outperformed either qcow2 or raw images were for large blocksize reads on fio. A qcow2 file can be defined as a copy-on-write (COW) layer on top of a backing image (which can be either a raw file or another qcow2 image). Configuration Machine: Q35-6. IMG format? Which is better and for what reasons? Thanks. Qcow2 or Raw? Which do you use? Which is a better option? I'm reworking my system and am about to reformat my drives to get Gentoo on zfs, so I'm sketching out my partitioning plan. The disk is reporting the wrong size and unallocated 142. Furthermore, disk Apr 11, 2024 · Raw vs. I tried with ARC both on and off (primarycache = all vs. Reverse order, changing the -O switch's value. So these tests can generally be seen as ZVOL vs. Jun 19, 2019 · Raw vs Qcow2: Qemu/KVM provides support for various image formats. 58GB that should be 250gb. NB: In my limited testing with RAW files, they seem to perform pretty much as QCOW2. So decided to move one of my VMs to cache: Powered down VM. However, in my reading, it appears the consensus is that QCOW2 is better than RAW feature wise, and some also throw ZVOLS into the mix as well. raw vs qcow2 (WIndows VM, UnRAID 6. ) Primary vDisk Type: qcow2 Commands List Virtual Machines virsh list --all List Snapshots Dec 4, 2018 · However, with the right settings, qcow2 can come very close to the performance of raw images. We would like to show you a description here but the site won’t allow us. Storage allows virtualized environment to read and write data over variety of different methods. img file, but that will essentially convert the thin provisioned disk to a thick one. But I have a final questions that I haven't been able to find the answer to yet: What is "better" for such a gaming VM? Mar 23, 2015 · As the overlay layer must be a Qcow2 file, you don't lose the ever-useful snapshot capability (RAW images don't support snapshots by themselves) The choice between base image + qcow2 overlay vs multiple full copies depends on your priority: For absolute performance, use fallocated RAW images. I wanted better performance than img files but didn't want to sacrifice snapshots or lose an entire NVMe device to a single VM. Feb 19, 2023 · qcow2 格式的文件虽然在性能上比rRaw 格式的有一些损失（主要体现在对于文件增量上，qcow2 格式的文件为了分配 cluster 多花费了一些时间），但是 qcow2 格式的镜像比 Raw 格式文件更小，只有在虚拟机实际占用了磁盘空间时，其文件才会增长，能方便的减少迁移 Dec 6, 2020 · My current installation of Proxmox 6. Should I convert them to . Aug 29, 2025 · This post describes the features of Raw disk image and Qcow2 disk image to let you know which one is better for your KVM or OpenStack environment. # qemu-img convert -O raw qcow2image. QCOW2 or . Jul 2, 2024 · VM Snapshots discussion thread. If needed, you can change the default locations for your domains, ISOs, or appdata shares. Hit Update and Started the VM. Complete rubbish, qcow2 is barely slower than raw at all these days. The I/O performance improvement over regul Raw (Unraid help says its the best performance and that qcow2 is still under development so I haven't touched it). Feb 22, 2024 · Im having problems when I convert to the QCOW2 format. Jul 21, 2025 · I've been experimenting with LVM-backed VM storage as a middle ground between file-based images and direct device passthrough. Oct 16, 2015 · Proxmox Docs suggests using Raw format for Windows VMs, because of the big performance gain. vmdk (VMWare) and . And does not boot. vdi (Virtualbox) images Mar 6, 2015 · For "thin provisioning" go with qcow2. I'd like to know if is there an advantage too using Raw format for Linux VMs, and when should we use qcow2 ? I'm using KVM to all VMs Apr 13, 2015 · raw is direct access to a hard disk device like /dev/sdx, it will be faster then qcow2. How do I successfully create QCOW2 or ZVOLS on ZFS RaidZ2 servers? Feb 19, 2025 · 主要是RAW和QCOW2这两种磁盘格式，其实他们都是一种文件格式，做为虚拟机的磁盘使用。 区别raw: 裸磁盘格式（默认的虚拟磁盘格式）raw，原意就是“未经加工”，也指未格式化的磁盘。 linux中，raw是磁盘映像的纯二进制映像格式。 Oct 25, 2019 · 4. Jun 15, 2024 · Hi! I'm planning on setting up "Daily-driver" Windows 11 VM and I'm wondering a bit about disk-performance, what would be best? I have a pool with 4 2TB Samsung 980 NVME SSD's in a raidz1 setup (also used for appdata), wich I'm planning to use for the VM-disk, with a disk-size of 512-768GB, what Feb 1, 2016 · Hi I am converting my vmware vmdks ready for UNRAID. In particular I would find it useful if it was also possible to use . Went in to Update VM with new settings, in "form view" and just clicked my way to the new location. Is there a problem for the Unraid KVM using QCOW2 converted with qemu-img. Raw vs. vm When you want to restore it, you have to convert it back. 5 so I can see only Primary vDisk Location and reference to the vmdisk file in the settings. I'm running unRaid 6. vm If the VM is running and you want to Explore the key differences between VMware's VMDK and QEMU's QCOW2 formats in virtualization. 但我全然不记得以前也过这样的操作, 如果没有的话, 以前又是如何引导的呢? May 5, 2015 · I don't see the option to change it from VM settings in unRaid as someone suggested earlier. it's faster for cloning, backing up, snapshots etc. The default size is 100 GB. Is there any reason for this restriction? Certainly qemu-img recognises other image formats. zdw44en mynmy usus5w8a zh uumebs 0ou4 brd oda i00584u vee3u6