From mboxrd@z Thu Jan 1 00:00:00 1970 From: Victor Stinner Subject: Re: Issues with KVM Date: Sat, 23 Jul 2011 11:20:09 +0200 Message-ID: <4E2A9249.3080006@haypocalc.com> References: <4E29D318.7050602@haypocalc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: List-ID: Hi, Le 22/07/2011 21:59, C Anthony Risinger a =C3=A9crit : > ) is the host FS btrfs? The host (Fedora) FS is btrfs, the VM (Debian) uses ext4 (or maybe ext3= ,=20 I will have to check). > ) are virtio modules in the initramfs (or kernel probably)? > ) are you sure virtio is being used (eg. are the disks called vdX vs = sdX)? > ) is the disk bus set to virtio (virtmanager)? I'm not sure. I will have to check. > ) is the disk's cache mode set to none [or maybe writeback] (virtmana= ger)? I don't remember, I will check. What is the effect of this option? (What is the effect on the host FS=20 (btrfs)?) > ) is the disk's storage format set to "raw", should be (virtmanager)? Yes, the image type is "raw". > ) is caching enabled on the image? () What do you mean? Is it possible to enable or disable the cache on a=20 specific file on the host (Fedora, btrfs)? Or you mean set cache to non= e=20 in the configuration of the VM? > probably need to change the cache mode on the disk, or if the host is > btrfs you need to flag the image with whetever is needed to prevent > continuous COWing. Can nodatacow option of btrfs have an effect on this issue? Is it=20 possible to set this option for a specific file or directory? Victor PS: I have subscribed to the mailing list. PS2: I'm not at home this week-end, I will check monday. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html