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i wanted to install a windows terminal server on a kvm hypervisor.

On the host i am using btrfs, i have read that there are some speed problems if i use btrfs whit libvirt. I wanted to use the btrfs rootfs on the same 4 hdd software raid 10 as the storage whitout separate boot paritition.

Option 1: Can i mix lvm whit btrfs and raid? All of them have raid implemented or maybee mdraid and separate lvm and brtfs? where to put swap?

Option 2: It is maybee possible make the guest image readonly and write the changes to RAM or somewhere else..??

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I'm not sure what particular performance problems you might be referring to, however, the well known issue is that the COW feature in btrfs will negatively impact guest performance. The way to deal with this is to turn off COW, either for the filesystem as a whole by mounting with "nodatacow", or for just the disk image file by passing "nocow=on" to qemu-img when creating the disk image.

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While possible, it is not generally recommended to use LVM with BTRFS, as the latter already implements volume management capabilities.

Anyway, BTRFS is not the better filesystem to use for virtual machines: even when disabling its CoW feature, it remains much slower than EXT4, XFS or even ZFS.

Here you can find an interesting, albeit dated, comparison of various filesystem and VM workloads.

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