FrequentlyAskedQuestions

From ISCSItarget

Contents 1 What is it? 2 What are the differences between Ardis and IET? 3 What are the differences between IET and UNH iSCSI implementation? 4 Are multiple targets supported? 5 However, MaxConnection is set to 1 by default 6 Can I configure security policy per a target? 7 Does a single target handle multiple logical units? 8 What device does the target provide to an initiator? 9 Are 2.6 kernels supported? 10 Are 64-bit architectures supported? 11 How can I dynamically configure? 11.1 Adding a target: 11.2 Adding a LUN: 12 How can I mount a volume exported by IET on the exporting machine? 13 What are the current state of iSCSI implementations in Linux?

What is it?

iSCSI Enterprise Target (IET) software is for building an iSCSI storage system on Linux.

The project was started by forking the Ardis target implementation with respect to the GPL. If you are interested in historical stuff (e.g. why did we start this project?), read this thread.

What are the differences between Ardis and IET?

There are many differences about the internal designs, although you don't notice them. Here are some noticable feature differences.

• Kernel patches are not necessary.
• SMP is supported.
• 2.6 kernels are supported.
• Targets, volumes, and accounts for authentication can be added and deleted dynamically.
• Regular files are supported.
• Many bugs are fixed.
• More functionalities in the iSCSI specification are supported.

What are the differences between IET and UNH iSCSI implementation?

This analysis on open source iSCSI target software might interest you.

Are multiple targets supported?

Yes. IET software can run multiple targets simultaneously. And each target can provide services to multiple initiators.

However, MaxConnection is set to 1 by default

MaxConnection means the maximum number of connections per initiator. Read RFC 3720 if you are interested in the details.

Can I configure security policy per a target?

Yes.

Does a single target handle multiple logical units?

Yes.

What device does the target provide to an initiator?

You can use files. That is, regular files, block devices. virtual block devices (like RAID or LVM).

Are 2.6 kernels supported?

We support only 2.6 kernels.

Are 64-bit architectures supported?

Yes.

How can I dynamically configure?

Use ietadm, which is a tool for managing IET software. You can perform the following operations to a running target.

Adding a target:

ietadm --op new --tid=[id] --params Name=iqn.foo.bar:baz

[id] must be unused. You can get a list of the currently used Target IDs by: cat /proc/net/iet/sessions

Adding a LUN:

Note: This adds a LUN to a pre-existing target.

ietadm --op new --tid=[id] --params Path=/path/to/exported/file,Type=fileio

[id] must be an already existing Target ID.

How can I mount a volume exported by IET on the exporting machine?

See this page about SelfMountingExportedVolumes.

What are the current state of iSCSI implementations in Linux?

These slides at OLS 2005 might interest you.