Thank you for buying via links and ads on this site,
which earn me advertising fees or commissions.
As an Amazon Associate I earn from qualifying purchases.

Other World Computing...
B&H Photo...
Amazon
As an Amazon Associate I earn from qualifying purchases.
Upgrade the memory of your 2020 iMac up to 128GB
877-865-7002
Today’s Deal Zone Items... Handpicked deals...
$3049 $2399
SAVE $650

$3508 $2998
SAVE $510

$998 $848
SAVE $150

$3999 $2998
SAVE $1001

$2299 $1799
SAVE $500

$1597 $1297
SAVE $300

$80 $33
SAVE $46

$2299 $1799
SAVE $500

$1898 $1498
SAVE $400

$2799 $2299
SAVE $500

$2299 $1799
SAVE $500

$600 $400
SAVE $200

$240 $175
SAVE $65

$699 $499
SAVE $200

$400 $300
SAVE $100

$1599 $1398
SAVE $201

$2027 $1597
SAVE $430

$1699 $999
SAVE $700

$180 $100
SAVE $80

$1199 $1099
SAVE $100

$1199 $1099
SAVE $100

$999 $949
SAVE $50

$400 $300
SAVE $100

$1699 $999
SAVE $700

Understanding Fault Tolerance

Fault tolerance means the ability of a system to continue working correctly and (usually) without interruption when a component fails—the ability to tolerate a failure of some kind. The general concept applies to power supplies, hard drives and SSDs and other system components, but nearly always is used in the context of storage devices (e.g. hard drives or SSDs).

Single drives

In the case of single drives (hard drive or SSD), there is internal fault tolerance: bad blocks are detected and mapped out and spare blocks substituted. This process is invisible to the user, but drives supporting SMART can relay their health status (e.g. how many bad blocks have been mapped out).

There can also be ECC (error correcting code) involved internally, which can detect a limited number of bit errors.

Protect Your Phone
NuGard KX Case for iPhones and iPads.
Outstanding protection against drops and impact!
Plus, excellent grip for wet hands, cycling, etc.

Storage systems

For storage systems, fault tolerance means that volumes associated with one or more drives continue to work even if one of the drives should fail. While the system continues to function, the failed drive must be replaced to restore the as-designed fault tolerant behavior.

When a fault occurs, it is essential to have a cold spare on hand so that the failed drive can be replaced immediately.

Use of fault tolerant forms of RAID generally means lower performance and loss of some storage capacity, yet the performance can still be very high.

RAID compared using four 4TB drives
  RAID-5 RAID 1+0 RAID-0 stripe RAID-1 mirror RAID SPAN JBOD
# Drives 4 4 4 4 4, concatenated 4
independent
non-RAID
Capacity: 12TB 8TB 16TB 4TB 16TB 16TB
Fault tolerance: single failure OK single failure OK
from each mirror
single failure kill volume three failures OK single failure kills volume independent
Read Speed ~3X 2X 4X 1X 1X, variable 1X
Write Speed 2.2X - 3X 2X 4X 1X 1X, variable 1X


OWC Accelsior 4M2 PCIe SSD
6000 MB/sec!
Mac or PC.


Ideal for Lightroom, Photoshop, video.
Capacity up to 16TB!
OWC Thunderblade Thunderbolt 3 SSD

Blazing fast, up to 16TB.

YEE HAH!



√ No more slow and noisy hard drives!

Deals Updated Daily at B&H Photo

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__