| Kasor 2001-09-25, 10:45 am |
| My friend email this to me, it is about Linux SAN
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Enterprise Linux users who are looking to merge the worlds of
IP and storage networking should check out the work being done
by the Linux-iSCSI Project.
Small computer system interface (SCSI) is the commonly-known
protocol used to interface computer hard drives to a system
board in a PC or server. SCSI is also used as a transport
method for connecting large data storage systems with front-end
servers in what are known as storage area networks (SANs). By
using a SAN, enterprise users do not have to tie their storage
to specific servers. According to SAN proponents, data
resources can be pooled in a SAN, allowing for easier
management of storage and faster access to data from servers.
The development of iSCSI (Internet SCSI) is aimed at allowing
servers to communicate with server-attached SCSI storage
systems over an IP network. The iSCSI protocol works by
encapsulating SCSI data into IP packets, which allows the data
to be sent over a standard TCP/IP network. This encapsulation
could be done by a storage router, such as the Cisco SN series
storage router, which sits in front of an SCSI storage array.
On the other end, an iSCSI-enabled host receives the IP traffic
from a storage router, then extracts the SCSI data from the IP
packets. Internet SCSI eliminates the 12-meter distance
limitation of server-attached SCSI storage, allowing an
enterprise to connect storage with servers across long
distances. Such a set up could be useful for doing redundant
backups of sensitive data to a remote site for disaster
recovery purposes.
This is where the iSCSI-Linux Project comes in. Developers have
created the necessary software for enabling a Linux server to
communicate with an iSCSI storage router. According to
developers, the software runs on top of the TCP/IP stack on a
Linux machine, acting as the translator between IP and SCSI.
The software requires version 2.2.16 of the Linux kernel, or
higher, in order to operate. Enterprises using iSCSI and SANs
could use the Linux-iSCSI software to cheaply deploy more hosts
that can communicate with a SCSI-based storage system. |