Kernel Korner - ATA Over Ethernet: Putting Hard Drives on the LAN
Because ATA over Ethernet puts inexpensive hard drives on the Ethernet network, some sysadmins might be interested in using AoE in a backup plan. Often, backup strategies involve tier-two storage—storage that is not quite as fast as on-line storage but also is not as inaccessible as tape. ATA over Ethernet makes it easy to use cheap ATA drives as tier-two storage.
But with hard disks being so inexpensive and seeing that we have stable software RAID, why not use the hard disks as a backup medium? Unlike tape, this backup medium supports instant access to any archived file.
Several new backup software products are taking advantage of filesystem features for backups. By using hard links, they can perform multiple full backups with the efficiency of incremental backups. Check out the Backup PC and rsync backups links in the on-line Resources for more information.
Putting inexpensive disks on the local network is one of those ideas that make you think, “Why hasn't someone done this before?” Only with a simple network protocol, however, is it practical to decouple storage from servers without expensive hardware, and only on a local Ethernet network can a simple network protocol work. On a single Ethernet we don't need the complexity and overhead of a full-fledged Internet protocol such as TCP/IP.
If you're using storage on the local network and if configuring access by creating Ethernet networks is sufficient, then ATA over Ethernet is all you need. If you need features such as encryption, routability and user-based access in the storage protocol, iSCSI also may be of interest.
With ATA over Ethernet, we have a simple alternative that has been conspicuously absent from Linux storage options until now. With simplicity comes possibilities. AoE can be a building block in any storage solution, so let your imagination go, and send me your success stories.
I owe many thanks to Peter Anderson, Brantley Coile and Al Dixon for their helpful feedback. Additional thanks go to Brantley and to Sam Hopkins for developing such a great storage protocol.
Resources for this article: /article/8201.
Ed L. Cashin has wandered through several academic and professional Linux roles since 1997, including Web application developer, system administrator and kernel hacker. He now works at Coraid, where ATA over Ethernet was designed, and he can be reached at email@example.com. He enjoys music and likes to listen to audio books on his way to martial arts classes.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- SUSE LLC's SUSE Manager
- Returning Values from Bash Functions
- My +1 Sword of Productivity
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- Tech Tip: Really Simple HTTP Server with Python
- Doing for User Space What We Did for Kernel Space
- Rogue Wave Software's Zend Server
- Parsing an RSS News Feed with a Bash Script
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide