VM Transfer Speeds

[Vito Reiter]

I've got a lot going on here, and I already know there's a better way to do this but this way is already setup and I want to know if there's a way to correct it or not. I have a ProxMox cluster that runs all my VM's with every VM having its storage on a FreeNAS NFS share. One of our VM's is a Windows 2008R2 Server and that one hosts all of our Windows shares that hold various data, the reason it's like this is because once upon a time it was a physical machine and the guy that imaged it to a VM didn't want to set up AD in FreeNAS. The virtual drive is a qcow2 with writeback enabled, I've done every single VM tune possible to speed it up. The problem here is a file transfer (using the same exact file from the same exact system) moves to the VM's share at about 20MB/s, while if I transfer to my Windows SMB share in FreeNAS it transfers at full GbE 120~MB/s. Now, the location of the VM's image file and the Windows SMB share in FreeNAS are the same location in the same volume. Any ideas why the performance is so slow to transfer to the VM?

I'm not expecting a solid answer given I'm asking about software this forum doesn't cover, but maybe someone has an answer? If the answer is setup AD in FreeNAS and recreate all of the shares in FreeNAS, I will do that. However, I like the setup that exists and would prefer to keep it if there is a solution.

Thanks all,
Build: FreeNAS-9.10.2-U3

Motherboard: Intel DX580G
Intel Xeon W3565 @ 3.2 GHz
2 x 4GB ECC RAM (8GB Total)
Boot: Mirrored 2x 120GB SSD's
VDEV1: RaidZ2 w/ 5x 1TB Drives
VDEV2: RaidZ2 w/ 5x 1TB Drives

 

[jgreco]

Storing SMB data directly to FreeNAS, especially on an 8GB RAM filer, is going to be faster. ZFS has some idea of the file-oriented nature of what you're doing, and it can be more efficient.

Storing the data as VM data is going to be difficult, especially since you're using RAIDZ2, which is a particularly bad choice for VM data.

https://forums.freenas.org/index.ph...d-why-we-use-mirrors-for-block-storage.44068/

https://forums.freenas.org/index.ph...xi-nfs-so-slow-and-why-is-iscsi-faster.12506/

 

[Vito Reiter]

Storing SMB data directly to FreeNAS, especially on an 8GB RAM filer, is going to be faster. ZFS has some idea of the file-oriented nature of what you're doing, and it can be more efficient.

Storing the data as VM data is going to be difficult, especially since you're using RAIDZ2, which is a particularly bad choice for VM data.

https://forums.freenas.org/index.ph...d-why-we-use-mirrors-for-block-storage.44068/

https://forums.freenas.org/index.ph...xi-nfs-so-slow-and-why-is-iscsi-faster.12506/

Thanks man, my other VM's don't require any sort of speed requirements when it comes to storage so not a big deal. I suppose I'll have to go onto the task of integrating Active Directory, which should've been done from the get go but apparently, I'm the only one that likes to research things here :) Probably better to not have a single 4TB file holding all of our data anyway.

 

[jgreco]

It isn't just speed. RAIDZ parity consumption for VM block storage is an issue as well, and overall it works out to a bad choice in the long run.

 

[Stux]

Would it be worth temporarily disabling sync writes to see if that improves performance noticeably?

If it does, it's the sync writes, and you can ameliorate that through high performance SLOG