Chapter 12. Class #12 - iSCSI, Miscellaneous Topics, and Conclusion

Table of Contents

Intro to iSCSI
Installing iSCSI
iSCSI Configuration
iSCSI as a Service
Commands to Manipulate iSCSI
Securing iSCSI
Additional Notes & Considerations for iSCSI
Questions, Comments, Complaints

Final class. We'll cover iSCSI, have Q & A, hand out completion certificates, and finish up.

Intro to iSCSI

iSCSI stands for Internet Small Computer System Interface. This protocol is actually a set of commands that manipulates disks and disk space, and is done over an ethernet connection. This allows a system to access remote storage devices with SCSI commands as though it were a local hard disk. Listed below are several iSCSI terms that need to be clarified before working with this utility.

Table 12.1. iSCSI Terms

Term Description
iSCSI initiator A client that requests access to an iSCSI storage device.
iSCSI target Remote storage device presented from an iSCSI server or "target portal".
iSCSI target portal An iSCSI server providing targets to the initiator.
IQN "iSCSI Qualified Name" A unique name required by both the initiator and the target.

Installing iSCSI

There is one package that is required for iSCSI installation. Install this package with the command `yum -y install iscsi-initiator-utils`.

iSCSI Configuration

Installation of the iSCSI package will created the directory '/etc/iscsi'. Configuration material for iSCSI is contained in that directory.

iSCSI as a Service

There are two services associated with iSCSI: iscsi & iscsid. They can be started, stopped, etc. by the typical means.

Commands to Manipulate iSCSI

The main command to manipulate iSCSI is `iscsiadm`.

Securing iSCSI

securing iSCSI port 3260???

Additional Notes & Considerations for iSCSI

Once the iSCSI phase of accessing the remote disk space is finished, the typical disk and filesystem commands and utilities are used to manipulate the disk. See the man pages for fdisk, fstab, mkfs, blkid, partprobe, mount, parted, cryptsetup, and crypttab. The material covered in previous chapters applies as well.

See the iSCSI Wikipedia Article and Open iSCSI for more information about the iSCSI specification and protocol. A couple of practical suggestions for working with iSCSI-accessed disks is to a) use UUIDs or labels for persistent mounts in '/etc/fstab', and provide _netdev as a mount option so that this device will not be mounted until after the network is up and running.

For specific steps in configuring an iSCSI device, see the section called "iSCSI Initiator Setup".