Slides for my talk at openSUSE Summit 2019 Nashville

1. Lee Duncan
SUSE Labs iSCSI Hacker
lduncan@suse.com
Setting up iSCSI providers
and clients on openSUSE

2. 2
A Short talk about using iSCSI
●
My Background
– SCSI and iSCSI experience
– Worked for SUN, HP, GE, AT&T, now SUSE
– Co-maintainer of open-iscsi initiator
– Co-maintainer of Linux kernel initiator code
– Maintainer of targets and initiator for SUSE
– Other github projects (gonzoleeman)

3. 3
iSCSI: What is it?
●
iSCSI is just SCSI over a transport, e.g. TCP/IP
– See RFC3270
●
SCSI is just a way that a computer and disc can talk
– The Computer makes requests: this client initiates all
communication
– The Disc responds: it’s target serves disc data to the
computer

4. 4
iSCSI: Why do I care about it?
●
Free and open software
●
Cheap: you do not need special hardware, other than your
network
●
Well used: it is generally reliable/mature
●
Well maintained
– New stuff still being added (e.g. tcmu_runner)
●
Can be building block for larger storage systems

5. 5
iSCSI: Basics
●
iSCSi uses initiators and targets
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A target is a server that serves up Disc LUs
●
An initiator is a client that wants to access LUs
●
We will use open-iscsi for our client
●
We will use targetcli-fb for our server
●
A picture might help ...

6. 6
iSCSI: Topology (simple)
NetworkNetwork
Client*
Client*
ServerServer
iSCSI InitiatoriSCSI Initiator
iSCSI TargetiSCSI Target
LUN0LUN0
open-iscsi
targetcli-fb/LIO
iqn.yyyy-mm.name-authority:unique-name
iqn.yyyy-mm.name-authority:unique-name
Storage

7. 7
iSCSI: Setting up the Target
●
We need a target for the initiator to connect to
– Using command line: targetcli(1)
●
Package: targetcli-fb (uses Python3)
– Using YaST GUI
●
Package yast2-iscsi-lio-server

8. 8
iSCSI: Setting up the Target (cont)
●
Using the Command Line
– Use the targetcli(1) command
– Can be called to do one thing or interactively
– Must be root
– Shell-like
●
Has a node hierarchy: root, directories, ...
●
Commands depend on where you are in tree

9. 9
iSCSI: Setting up the Target (cont)
●
Two parts to a target (must be connected)
– Backstore
●
Where the bits actually live
●
Several different types (file, disc, ...)
– Target front-end
●
Name (iqn.*)
●
Portal(s) (IP:Port)
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LU(s)
●
ACL(s) (Initiator IQN)

10. 10
iSCSI: Setting up the Target (cont)

11. 11
iSCSI: Setting up the Target (cont)

12. 12
iSCSI: Setting up the Target (cont)

13. 13
iSCSI: Setting up the Target (cont)

14. 14
iSCSI: Setting up the Target (cont)

15. 15
iSCSI: Setting up the Target (cont)
●
Setting up the target using yast:
– Navigate to Network Services → iSCSI LIO Target
●
NOTE: yast does not allow configuring individual ACLs (i.e.
demo mode)

16. 16
iSCSI: Setting up the Target (cont)

17. 17
iSCSI: Setting up the Target (cont)

18. 18
iSCSI: Setting up the Target (cont)

19. 19
iSCSI: Setting up the Target (cont)

20. 20
iSCSI: Setting up the Target (cont)

21. 21
iSCSI: Setting up the Target (cont)

22. 22
iSCSI: Setting up the Initiator
●
The initiator uses the open-iscsi package
– Installed and enabled by default
●
Can be configured using
– Command line: iscsiadm(1)
– YaST (uses yast2-iscsi-client package)

23. 23
iSCSI: Setting up the Initiator (cont)
●
Initiator uses two phases to connect:
– Discovery: find target(s) at IP:Port
– Login: connect to discovered target(s)
●
Command line
– iscsiadm(1)

24. 24
iSCSI: Setting up the Initiator (cont)

25. 25
iSCSI: Setting up the Initiator (cont)

26. 26
iSCSI: Setting up the Initiator (cont)
●
Setting up initiator using yast
– Uses the yast2-iscsi-client package
– Navigate to Network Services → iSCSI Initiator

27. 27
iSCSI: Setting up the Initiator (cont)

28. 28
iSCSI: Setting up the Initiator (cont)

29. 29
iSCSI: Setting up the Initiator (cont)

30. 30
iSCSI: Setting up the Initiator (cont)

31. 31
iSCSI: Setting up the Initiator (cont)

32. 32
iSCSI: Setting up the Initiator (cont)

33. 33
iSCSI: Setting up the Initiator (cont)

34. 34
iSCSI: Setting up the Initiator (cont)

35. 35
iSCSI: That’s It!
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iSCSI is easy to set up on openSUSE
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You can use command line or GUI
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You can roll your own SAN
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For more info:
– http://www.open-iscsi.com
– https://github.com/open-iscsi/targetcli-fb
– http://www.opensuse.org

36. Join Us at www.opensuse.org
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●
Contact:
lduncan@suse.com

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Credits
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Richard Brown
rbrown@opensuse.org
Design & Inspiration
openSUSE Design Team
http://opensuse.github.io/branding-guidelines/
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