Windows 10: Linux VM's -- RAW HDD's - which native file system to use

Hi folks
just wondering if any performance gurus out there using Linux VM's with physical HDD's / SSD's have done any analysis on which file system(s) should they use for maximum Disk performance --- I'm interested when the Physical disk(s) is /are used rather than using "Virtual Disks".

I've basically narrowed the choices to EXT4, XFS and BTRFS.
I'm leaning towards BTRFS as it seems to handle loads of smaller files better than the other two (I've around 150,000 music tracks - probably the largest size is around 600 Mb and is also good with RAID / Pooled volumes (LVM etc) . EXT4 is a bit long in the tooth these days so journalling probably isn't any good in it, and XFS seems fine for large files, RAID etc

Any volunteers -- anyone. I think the best way to get near native performance from a VM is to pass thru as much hardware as possible to the VM and use the appropriate GUEST OS drivers etc which is why I'm interested in the performance of these file systems.
and have to supply a load more users so I want to test on a VM the best configuration for these things before I do it "for real".

Cheers
jimbo.

:)

 

Linux VM's -- RAW HDD's - which native file system to use

Hi folks
just wondering if any performance gurus out there using Linux VM's with physical HDD's / SSD's have done any analysis on which file system(s) should they use for maximum Disk performance --- I'm interested when the Physical disk(s) is /are used rather than using "Virtual Disks".

I've basically narrowed the choices to EXT4, XFS and BTRFS.
I'm leaning towards BTRFS as it seems to handle loads of smaller files better than the other two (I've around 150,000 music tracks - probably the largest size is around 600 Mb and is also good with RAID / Pooled volumes (LVM etc) . EXT4 is a bit long in the tooth these days so journalling probably isn't any good in it, and XFS seems fine for large files, RAID etc

Any volunteers -- anyone. I think the best way to get near native performance from a VM is to pass thru as much hardware as possible to the VM and use the appropriate GUEST OS drivers etc which is why I'm interested in the performance of these file systems.
and have to supply a load more users so I want to test on a VM the best configuration for these things before I do it "for real".

Cheers
jimbo.

 

Pass Native file systems to GUEST OS's for better I/O


Hi folks

sometimes when running VM's - especially as servers (nothing wrong in using a VM as a server) you will considerably improve I/O throughput if you use the native file system for the OS instead of using Virtual HDD's.

For instance if you run Windows Guests on a Linux host in the classical way with virtual HDD's the I/O has to handle both the vm hdd and the Windows file handler (ntfs-3g in Linux --which mounts the fuse (windows ntfs handler) in the kernel).

Similarly for Linux guests running on Windows hosts .

Attaching external HDD's to the VM is no problem as these can be attached with native file systems in the usual way.

The problem is with internal HDD's.

You need to allocate the WHOLE disk and in the VM setup specify it as a RAW HDD. That way Windows etc won't complain if it sees an HDD with a foreign file system on it or ask you to re-format it every time you re-boot the HOST system.

On the Guest just handle the HDD in the usual way e.g if Linux guest just mount the device or with Windows the HDD should be recognized as soon as the VM is powered on.

This should beef up your I/O on VM's quite considerably. Note use this for DATA. Keep the guest OS itself on a Virtual disk - and an SSD is the best place for this.

The 3 main sets of Vm software people use on these forums (VMware, vbox and Hyper-V) all allow for RAW HDD pass through to the guest.

If you can run the VM on an SSD (the OS part) then so much the better too.

Cheers
jimbo

 

Windows HOST, attach Linux external USB to Linux VM


Hi there

I usually run a LINUX HOST for testing Windows VM's - but I need to test some new releases of various Linux distros so I've created some VM's --easy enough and running them on a Windows Host.

However I can't attach a USB drive with a Linux file system (XFS) to the VM as the Windows HOST rejects the HDD wanting me to format it !!. There's 2.7 TB of media files on it - I want to test running media server in a VM.

Anybody know how to bypass the Windows nag prompt about the HDD and be able to attach it direct to the VM.

(The other way round is no problem -- never a problem loading NTFS HDD's on to Linux machines -- however the NTFS file system is SLOW compared with XFS -- on USB3 device on Native windows transfer rate of 1 TB of files from fast NTFS HDD to NTFS USB3 device is max 82 Mib/s - average for whole transfer. On same machine with Native Linux and XFS to XFS (using same HDD's and USB 3 port avg speed is 350 mib/s !! -- HUGE difference !!!).

Note I have to have a Windows Host for this --I know I could run Linux VM's from a Linux Host but in this case I do have to use a Windows Host as that will be the destination system at the end of testing.

BTW I'm running VMWARE workstation 12.1 on W10 Pro Host.

Cheers
jimbo