Re: Large qcow2 performance

2019-09-25 Thread Andrew Martin
- Original Message - > From: "Alberto Garcia" > To: "qemu-discuss" > Sent: Wednesday, September 25, 2019 8:05:50 AM > Subject: Re: Large qcow2 performance > On Tue, Sep 24, 2019 at 02:45:10PM -0500, Andrew Martin wrote: >> Hi Berto, >

Re: Large qcow2 performance

2019-09-24 Thread Andrew Martin
- Original Message - > From: "Alberto Garcia" > To: "qemu-discuss" > Sent: Tuesday, September 24, 2019 10:15:56 AM > Subject: Re: Large qcow2 performance > On Mon, Sep 23, 2019 at 03:17:39PM -0500, Andrew Martin wrote: > >> I am considering

Large qcow2 performance

2019-09-23 Thread Andrew Martin
Hello, I am considering creating a VM with a large qcow2, around 6TB in size. This Linux VM will be reading and writing a lot of small files to this very large qcow2 using the VirtIO driver. Are there any concerns or guidance about creating such a large qcow2, or performance issues with small

Re: [Qemu-discuss] Understanding QEMU Cache Modes and Emulated Disk Write Cache

2016-08-17 Thread Andrew Martin
- Original Message - > From: "Jakob Bohm" <jb-gnumli...@wisemo.com> > To: qemu-discuss@nongnu.org > Sent: Wednesday, August 17, 2016 9:34:32 AM > Subject: Re: [Qemu-discuss] Understanding QEMU Cache Modes and Emulated Disk > Write Cache > > On

Re: [Qemu-discuss] Understanding QEMU Cache Modes and Emulated Disk Write Cache

2016-08-17 Thread Andrew Martin
- Original Message - > From: "Fam Zheng" <f...@redhat.com> > To: "Andrew Martin" <amar...@xes-inc.com> > Cc: qemu-discuss@nongnu.org > Sent: Wednesday, August 17, 2016 2:50:36 AM > Subject: Re: [Qemu-discuss] Understanding QEMU Cache Modes a

[Qemu-discuss] Understanding QEMU Cache Modes and Emulated Disk Write Cache

2016-08-16 Thread Andrew Martin
Hello, I am running QEMU 2.5 on Ubuntu 16.04. My guests are a mixture of Linux (Ubuntu 12.04 and newer with ext4) and Windows. The guest qcow2 images are stored in a ZFS filesystem with sync=standard (on top of a mirrored vdev of SSDs) on the host Ubuntu 16.04 OS. After having read through

[Qemu-discuss] QCOW2 Image Corrupted - overlaps with active L2 table

2016-03-23 Thread Andrew Martin
Hello, I am running QEMU 2.0.0 and libvirt 1.2.2 on Ubuntu 14.04 LTS. My KVM VMs use QCOW2 files stored in a local ext4 filesystem. This normally works great, however today I experienced corruption of one of my VMs disks, causing a kernel panic in the VM: qcow2: Preventing invalid write on

[Qemu-discuss] Clarification about disk cache options

2014-08-08 Thread Andrew Martin
barriers states that Write barriers enforce proper on-disk ordering of journal commits, making volatile disk write caches safe to use, at some performance penalty. Does this apply to qcow2 VM images? Thanks, Andrew Martin

Re: [Qemu-discuss] Add PCI Passthrough for multiple devices on same bus?

2013-09-12 Thread Andrew Martin
Technology Ltd. 4-Port PCIe Serial Adapter How can I give the VM access to these serial ports, either by PCI pass-through or by virtualizing them in the host somehow? Thanks, Andrew - Original Message - From: Tony Su ton...@su-networking.com To: Andrew Martin amar...@xes-inc.com Cc