Kernel Korner - Storage Improvements for 2.6 and 2.7

The Linux 2.6 kernel has improved Linux's storage capabilities with advances such as the anticipatory I/O scheduler and support for storage arrays and distributed filesystems.
Future Trends

It appears that storage systems will continue to change. The fact that LAN gear is much less expensive than SAN gear augurs well for iSCSI, which runs the SCSI protocol over TCP. However, widespread use of iSCSI raises some security issues, because failing to disable IP forwarding could let someone hack your storage system. Some believe that serial ATA (SATA) is destined to replace SCSI in much the same way that SCSI itself replaced proprietary disk-interface protocols. Others believe that RAID arrays will be replaced by object stores or object-store targets, and in fact there is an emerging standard for such devices. Either way, interfacing to storage systems will continue to be challenging and exciting.


I owe thanks to the Linux community but especially to Daniel Phillips and Hugh Dickins for most excellent discussions and to Mike Anderson and Badari Pulavarty for their explanations of recent 2.6 kernel capabilities and their review of this paper. I also am grateful to Bruce Allan and Trond Myklebust for their thoughts on resolving the NFS lockd issue.

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Paul E. McKenney is a distinguished engineer at IBM and has worked on SMP and NUMA algorithms for longer than he cares to admit. Prior to that, he worked on packet-radio and Internet protocols, but long before the Internet became popular. His hobbies include running and the usual house-wife-and-kids habit.