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Diffstat (limited to 'qemu-doc.texi')
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diff --git a/qemu-doc.texi b/qemu-doc.texi index 154b82dcc9..9c3cb62ee3 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -421,6 +421,7 @@ snapshots. * disk_images_fat_images:: Virtual FAT disk images * disk_images_nbd:: NBD access * disk_images_sheepdog:: Sheepdog disk images +* disk_images_iscsi:: iSCSI LUNs @end menu @node disk_images_quickstart @@ -695,6 +696,61 @@ qemu-img create sheepdog:@var{hostname}:@var{port}:@var{image} @var{size} qemu sheepdog:@var{hostname}:@var{port}:@var{image} @end example +@node disk_images_iscsi +@subsection iSCSI LUNs + +iSCSI is a popular protocol used to access SCSI devices across a computer +network. + +There are two different ways iSCSI devices can be used by QEMU. + +The first method is to mount the iSCSI LUN on the host, and make it appear as +any other ordinary SCSI device on the host and then to access this device as a +/dev/sd device from QEMU. How to do this differs between host OSes. + +The second method involves using the iSCSI initiator that is built into +QEMU. This provides a mechanism that works the same way regardless of which +host OS you are running QEMU on. This section will describe this second method +of using iSCSI together with QEMU. + +In QEMU, iSCSI devices are described using special iSCSI URLs + +@example +URL syntax: +iscsi://[<username>[%<password>]@@]<host>[:<port>]/<target-iqn-name>/<lun> +@end example + +Username and password are optional and only used if your target is set up +using CHAP authentication for access control. +Alternatively the username and password can also be set via environment +variables to have these not show up in the process list + +@example +export LIBISCSI_CHAP_USERNAME=<username> +export LIBISCSI_CHAP_PASSWORD=<password> +iscsi://<host>/<target-iqn-name>/<lun> +@end example + +Howto set up a simple iSCSI target on loopback and accessing it via QEMU: +@example +This example shows how to set up an iSCSI target with one CDROM and one DISK +using the Linux STGT software target. This target is available on Red Hat based +systems as the package 'scsi-target-utils'. + +tgtd --iscsi portal=127.0.0.1:3260 +tgtadm --lld iscsi --op new --mode target --tid 1 -T iqn.qemu.test +tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 \ + -b /IMAGES/disk.img --device-type=disk +tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 \ + -b /IMAGES/cd.iso --device-type=cd +tgtadm --lld iscsi --op bind --mode target --tid 1 -I ALL + +qemu-system-i386 -boot d -drive file=iscsi://127.0.0.1/iqn.qemu.test/1 \ + -cdrom iscsi://127.0.0.1/iqn.qemu.test/2 +@end example + + + @node pcsys_network @section Network emulation |