905 research outputs found
Multi-Terabyte EIDE Disk Arrays running Linux RAID5
High-energy physics experiments are currently recording large amounts of data
and in a few years will be recording prodigious quantities of data. New methods
must be developed to handle this data and make analysis at universities
possible. Grid Computing is one method; however, the data must be cached at the
various Grid nodes. We examine some storage techniques that exploit recent
developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5)
include both parity and striping. The striping improves access speed. The
parity protects data in the event of a single disk failure, but not in the case
of multiple disk failures.
We report on tests of dual-processor Linux Software RAID-5 arrays and
Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with
250 and 300 GB disks, for use in offline high-energy physics data analysis. The
price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be
scaled to sizes affordable to small institutions and used when fast random
access at low cost is important.Comment: Talk from the 2004 Computing in High Energy and Nuclear Physics
(CHEP04), Interlaken, Switzerland, 27th September - 1st October 2004, 4
pages, LaTeX, uses CHEP2004.cls. ID 47, Poster Session 2, Track
Redundant Arrays of IDE Drives
The next generation of high-energy physics experiments is expected to gather
prodigious amounts of data. New methods must be developed to handle this data
and make analysis at universities possible. We examine some techniques that use
recent developments in commodity hardware. We test redundant arrays of
integrated drive electronics (IDE) disk drives for use in offline high-energy
physics data analysis. IDE redundant array of inexpensive disks (RAID) prices
now equal the cost per terabyte of million-dollar tape robots! The arrays can
be scaled to sizes affordable to institutions without robots and used when fast
random access at low cost is important. We also explore three methods of moving
data between sites; internet transfers, hot pluggable IDE disks in FireWire
cases, and writable digital video disks (DVD-R).Comment: Submitted to IEEE Transactions On Nuclear Science, for the 2001 IEEE
Nuclear Science Symposium and Medical Imaging Conference, 8 pages, 1 figure,
uses IEEEtran.cls. Revised March 19, 2002 and published August 200
Investigating SRAM PUFs in large CPUs and GPUs
Physically unclonable functions (PUFs) provide data that can be used for
cryptographic purposes: on the one hand randomness for the initialization of
random-number generators; on the other hand individual fingerprints for unique
identification of specific hardware components. However, today's off-the-shelf
personal computers advertise randomness and individual fingerprints only in the
form of additional or dedicated hardware.
This paper introduces a new set of tools to investigate whether intrinsic
PUFs can be found in PC components that are not advertised as containing PUFs.
In particular, this paper investigates AMD64 CPU registers as potential PUF
sources in the operating-system kernel, the bootloader, and the system BIOS;
investigates the CPU cache in the early boot stages; and investigates shared
memory on Nvidia GPUs. This investigation found non-random non-fingerprinting
behavior in several components but revealed usable PUFs in Nvidia GPUs.Comment: 25 pages, 6 figures. Code in appendi
The D0 Run II Impact Parameter Trigger
Many physics topics to be studied by the D0 experiment during Run II of the
Fermilab Tevatron ppbar collider give rise to final states containing
b--flavored particles. Examples include Higgs searches, top quark production
and decay studies, and full reconstruction of B decays. The sensitivity to such
modes has been significantly enhanced by the installation of a silicon based
vertex detector as part of the DO detector upgrade for Run II. Interesting
events must be identified initially in 100-200 microseconds to be available for
later study. This paper describes custom electronics used in the DO trigger
system to provide the real--time identification of events having tracks
consistent with the decay of b--flavored particles.Comment: To be submitted to Nucl. Instrum. Methods A. 56 pages, 31 figure
Performance Considerations for Gigabyte per Second Transcontinental Disk-to-Disk File Transfers
Moving data from CERN to Pasadena at a gigabyte per second using the next
generation Internet requires good networking and good disk IO. Ten Gbps
Ethernet and OC192 links are in place, so now it is simply a matter of
programming. This report describes our preliminary work and measurements in
configuring the disk subsystem for this effort. Using 24 SATA disks at each
endpoint we are able to locally read and write an NTFS volume is striped across
24 disks at 1.2 GBps. A 32-disk stripe delivers 1.7 GBps. Experiments on higher
performance and higher-capacity systems deliver up to 3.5 GBps
- …