xen支援的塊裝置

xen支援的塊裝置

1. 實體塊裝置（Dom0中的實體塊裝置，如邏輯卷）

    phy:/dev/cdrom

    phy:/dev/xenvg/vm1

2. 磁盤鏡像

    file:/root/tst.iso（使用loopback）

    nbd: ip_port （網絡塊裝置）

    tap:cdrom:/dev/sr0（CD裝置）

    tap:aio:/path/file  （blktap）

    tap:qcow:/mnt/disks/sles10sp1.iso.qcow（QEMU磁盤鏡像）

    tap:vmdk:/mnt/disks/sles10sp1.iso.vmdk（Vmware磁盤鏡像）

3. ISCSI裝置：

    iscsi:iqn.2001-04.com.acme@0ac47ee2-216e-452a-a341-a12624cd0225

4. NPIV裝置：

    npiv:210400e08b80c40f

file與tap的差別

file: uses dom0 kernel page cache, and thus might give better performance than phy: or tap:aio:,

but it's also more insecure because of the caching.

tap:aio: uses direct IO, so it bypasses dom0 kernel caches, and works like phy: in that sense.

blktap1 provides also other modes than :aio, like: qcow, but those were not very stable or fast,

    disk = ['tap:aio:<FILENAME>,sda1,w']

    disk = ['tap:qcow:<FILENAME>,sda1,w']

so blktap2 was developed. for blktap1 see: http://wiki.xensource.com/xenwiki/blktap .

blktap2 also has vhd image support including snapshots and cloning.

    disk = [ "tap:tapdisk:vhd:/path/images/disk.vhd,xvda,w" ]

    disk = [ "tap2:tapdisk:vhd:/path/images/disk.vhd,xvda,w" ]

See here: http://wiki.xensource.com/xenwiki/blktap2 .

本文轉自feisky部落格園部落格，原文連結：http://www.cnblogs.com/feisky/archive/2012/01/31/2332809.html，如需轉載請自行聯系原作者