Autonomous storage management for low-end computing environments

To make storage management transparent to users, enterprises rely on expensive storage infrastructure, such as high end storage appliances, tape robots, and offsite storage facilities, maintained by full-time professional system administrators. From the user's perspective access to data is seamless regardless of location, backup requires no periodic, manual action by the user, and help is available to recover from storage problems. The equipment and administrators protect users from the loss of data due to failures, such as device crashes, user errors, or virii, as well as being inconvenienced by the unavailability of critical files. Home users and small businesses must manage increasing amounts of important data distributed among an increasing number of storage devices. At the same time, expert system administration and specialized backup hardware are rarely available in these environments, due to their high cost. Users must make do with error-prone, manual, and time-consuming ad hoc solutions, such as periodically copying data to an external hard drive. Non-technical users are likely to make mistakes, which could result in the loss of a critical piece of data, such as a tax return, customer database, or an irreplaceable digital photograph. In this thesis, we show how to provide transparent storage management for home and small business users We introduce two new systems: The first, PodBase, transparently ensures availability and durability for mobile, personal devices that are mostly disconnected. The second, SLStore, provides enterprise-level data safety (e.g. protection from user error, software faults, or virus infection) without requiring expert administration or expensive hardware. Experimental results show that both systems are feasible, perform well, require minimal user attention, and do not depend on expert administration during disaster-free operation. PodBase relieves home users of many of the burdens of managing data on their personal devices. In the home environment, users typically have a large number of personal devices, many of them mobile devices, each of which contain storage, and which connect to each other intermittently. Each of these devices contain data that must be made durable, and available on other storage devices. Ensuring durability and availability is difficult and tiresome for non-expert users, as they must keep track of what data is stored on which devices. PodBase transparently ensures the durability of data despite the loss or failure of a subset of devices; at the same time, PodBase aims to make data available on all the devices appropriate for a given data type. PodBase takes advantage of storage resources and network bandwidth between devices that typically goes unused. The system uses an adaptive replication algorithm, which makes replication transparent to the user, even when complex replication strategies are necessary. Results from a prototype deployment in a small community of users show that PodBase can ensure the durability and availability of data stored on personal devices under a wide range of conditions with minimal user attention. Our second system, SLStore, brings enterprise-level data protection to home office and small business computing. It ensures that data can be recovered despite incidents like accidental data deletion, data corruption resulting from software errors or security breaches, or even catastrophic storage failure. However, unlike enterprise solutions, SLStore does riot require professional system administrators, expensive backup hard- ware, or routine, manual actions on the part of the user. The system relies on storage leases, which ensure that data cannot be overwritten for a pre-determined period, and an adaptive storage management layer which automatically adapts the level of backup to the storage available. We show that this system is both practical, reliable and easy to manage, even in the presence of hardware and software faults

Flexible allocation and space management in storage systems

In this dissertation, we examine some of the challenges faced by the emerging networked storage systems. We focus on two main issues. Current file systems allocate storage statically at the time of their creation. This results in many suboptimal scenarios, for example: (a) space on the disk is not allocated well across multiple file systems, (b) data is not organized well for typical access patterns. We propose Virtual Allocation for flexible storage allocation. Virtual allocation separates storage allocation from the file system. It employs an allocate-on-write strategy, which lets applications fit into the actual usage of storage space without regard to the configured file system size. This improves flexibility by allowing storage space to be shared across different file systems. We present the design of virtual allocation and an evaluation of it through benchmarks based on a prototype system on Linux. Next, based on virtual allocation, we consider the problem of balancing locality and load in networked storage systems with multiple storage devices (or bricks). Data distribution affects locality and load balance across the devices in a networked storage system. We propose user-optimal data migration scheme which tries to balance locality and load balance in such networked storage systems. The presented approach automatically and transparently manages migration of data blocks among disks as data access patterns and loads change over time. We built a prototype system on Linux and present the design of user-optimal migration and an evaluation of it through realistic experiments

Carrizozo Outlook, 02-18-1916

https://digitalrepository.unm.edu/c_outlook_news/1050/thumbnail.jp

Albuquerque Morning Journal, 03-02-1922

https://digitalrepository.unm.edu/abq_mj_news/1492/thumbnail.jp

Life Sciences Program Tasks and Bibliography for FY 1997

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1997. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive internet web page

The LANDSAT Tutorial Workbook: Basics of Satellite Remote Sensing

Most of the subject matter of a full training course in applying remote sensing is presented in a self-teaching mode in this how-to manual which combines a review of basics, a survey of systems, and a treatment of the principles and mechanics of image analysis by computers, with a laboratory approach for learning to utilize the data through practical experiences. All relevant image products are included

Report of the Public Lands Commission, created by the Act of March 3, 1879, relating to public lands in the western portion of the United States and to the operation of existing land laws

Report of the Public Lands Commission. [1923] Codification of laws, and recommendations for legislation; Indian reservations in Utah; etc