In engineering: Redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe. In information theory: It is the number of bits used to transmit a message minus the number of ...

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2answers
35 views

What (if anything) do I gain by mirroring partitions on the same USB drive?

I have a small amount (a few dozen items of a few kilobytes each) of essential data to store, which I will need to access over the coming decades. While the data is highly confidential, its value to ...
0
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1answer
17 views

Network structure for dual redundancy

Company is looking to upgrade their network with new equipment and while at it, I'd like to architect it to make it more secure, faster, etc. The Agg Switch will have 1 connection to each Core Switch....
2
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1answer
107 views

Is a RAID1 (mirror) with 2 x 4TB drives and ZFS (through freenas) okay?

I'm looking to create a freenas RAID1 using two 4TB drives. It's going to be my primary location for a generic backup location (use rsnapshot for local files and keeping computer dd'd images) and I'...
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3answers
113 views

What is the other alternative technique of RAID? [closed]

I've been searching about this topic but I keep getting RAID only. I was told that there is another technique for data recovery and redundancy that replaces RAID. Kindly, can someone enlighten me. ...
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1answer
30 views

Prevent data loss through degradation, by making redundant copies to disc

I am about to store my PGP key to a 700MB disc. The key is (compressed) ~ 7KB in size. That is a whole lot space not used. A whole lot space that, if filled, could enable my drive to get at least one ...
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0answers
61 views

How to setup redundant ejabberd servers?

I currently have an ejabberd server running at domain A. It has a bunch of users with accounts like xyz@A. I want to setup alternative servers so that if A is down, clients can transparently use ...
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0answers
17 views

Redundancy: Is it worth the extra effort to add more servers?

We currently have the following setup: Data center A / front end server -> back end server -> db cluster / ...
2
votes
0answers
232 views

Proper network architecture for fault tolerant multi WAN multi building WLAN setup

I need help with deciding the correct network architecture for a guest WLAN deployment. We have 3 buildings, and each of them has its own LTE router (Mikrotik RB411U) connected to an Ubiquiti ...
1
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0answers
35 views

tahoe-lafs: one full copy of every file per server

I am attempting to use Tahoe-LAFS to make data available on all the machines I have set a share up on. At the moment, there are two machines acting as storage nodes. I will soon be adding a third. ...
1
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0answers
146 views

reliable/redundant PSU for SOHO server build

I am after reliable SOHO server build. I went with ECC RAM, quality NAS-grade harddrive and now I am looking at the PSU. I cannot seem to find any good redundant PSUs that would fit into the ATX form-...
1
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0answers
30 views

Is there a way to use the empty space on a CD image to enhance error correction (for example entire second copies of file)

I need to write a single file to a CD and the rest of the space is just going to be left unused. Is there a way to use the rest of the space to enhance the chances of the file being recoverable even ...
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2answers
33 views

DNS records: redundancy, and auxiliary servers

I have a domain, this domain points to a front end server. I have two front end servers, one ddos protected intreppid, with 20 GB/ps, other protected with secured servers from 2 to 10 GB/ps. So a DDOS ...
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2answers
3k views

Is a home NAS reliable to keep your data on (no other backups)?

The question came up while I was thinking to move some data (e.g.) pictures, old but important other data solely to the NAS (private use, no business level). My NAS is a simple 2 disk RAID system. I ...
0
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2answers
36 views

Raid 5 for more than one failing disk [closed]

RAID 5 works the following: Disk1 | Disk2 | Disk3 A | B | A xor B A xor B is called the parity and it can be on a different disk for different blocks. Now, whenever one disk fails, one can ...
0
votes
1answer
356 views

What GPT partition type to use for protecting DRBD metadata?

I'm planning to install a DRBD device on a (replicated) disk with two GPT partitions. DRBD requires some space for (preferentially "internal") metadata at the end of the underlying device. I'm ...
0
votes
2answers
548 views

Adding parity to backup dvds

I am backing up about 1.8GB of pictures to a dvd, but because over half the disk is free, I would like to add parity of the free space so that data can be read even after some data corruption has ...
1
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0answers
38 views

Intra-disk redundancy options

I have enough single disk systems deployed in harsh-environments that https://en.wikipedia.org/wiki/Bit_rot is a problem. Disks get corrupted regularly. My question is, if I'm willing to sacrifice a ...
2
votes
2answers
554 views

Is there a type of redundant disk filesystem that allows for some loss of data?

I'm building a media server on a budget. Currently, the design is to have four 500GB disks in a JBOD-type format giving me one large 2TB store. The problem is if any disk fails, I lose the whole array'...
2
votes
1answer
715 views

How to wrap an UDP connection to improve resistance agains packet loss?

Suppose there is UDP connection that does not expect much packet loss. Are there already tools that allow wrapping a UDP connection to gain more reliability at expence of bandwidth and overhead, for ...
1
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0answers
712 views

What is the risk of removing old Python versions on OSX?

I have a stock install of OSX (10.6). It has a whole bunch of different versions of Python installed: versions 2.3, 2.4, 2.5, and 2.6 came stock with the system. I can view them all in /Library/...
2
votes
0answers
79 views

set static Network settings, enable a wifi adapter

Here is my scenario, I have a computer with a LAN Connection and a WiFi Connection, running Windows XP Pro. I have a local network router (WRVS4400Nv2 from Cisco) with Wireless access and a separate ...
1
vote
2answers
308 views

Backing Up vs. Redundancy [closed]

I'm currently in stage 2 of 3 of building my home workstation. What this means is that my RAID-0 array of solid state disks will be backed up nightly to a RAID-5 or RAID-6 array of traditional ...
0
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1answer
73 views

ADSL Connections

Can you have two ADSL connections on a single phone line? Or by law of IT, do two Broadband connections require two separate phone lines and BT master sockets?
1
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1answer
584 views

Can I ensure data redundancy on the server when I use RSYNC?

Let's say I have server which provides a mission critical services, these services rely on data which are synced from another server. The question is whenever I can assure data redundancy on the ...
0
votes
1answer
293 views

Setting up Raid 1 Array for Home Server

I'm not sure if this is even possible, but it's worth asking on here! Essentially I have a old machine at home (well, not old hardware wise, but I recently built a new gaming rig), which I decided to ...
2
votes
1answer
2k views

What should I do when i get this data cyclic error trying to copy files?

I was trying to copy a file from my local hard drive to an external hard drive and i am getting this error. Cannot copy IMG_9212: Data error (cyclic redundancy check). Should i be worried about ...
2
votes
4answers
2k views

Linux software RAID robustness for RAID1 vs other RAID levels

I have a RAID5 array running and now also a raid1 that I set up yesterday. Since RAID5 calculates parity it should be able to catch silent data corruption on one disk. However for RAID1 the disks are ...
0
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0answers
423 views

Redundant default gateways on LAN

I have two default gateways in my network: 192.168.1.1 and 192.168.1.2. Is there a way to make Windows clients to detect the dead gateway and chnage over to the wowrking one automatically? My gateways ...
4
votes
2answers
4k views

How does RAID 1 determine whether a disk is corrupted?

I've built a RAID 1 array of 2 disks, A and B. That means that every bit on A is equal to a bit on B. If one disk fails, I can safely retrieve my data from the other disk. But then I started ...
0
votes
1answer
546 views

Redundant CTRL-SPACE proposal in Eclipse

How do I remove the redundant Ctrl-Space proposal in Eclipse? SWT JPA JAX-WS etc. Example: I just need Java standard first time click Ctrl-Space proposal.
1
vote
2answers
426 views

DFS for a several small clusters over WAN

My friends and I all have TBs on our system(s). None of us have any full backups which are geographically distributed however, because at that amount of data, solutions such as Dropbox, S3, et al. are ...
10
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3answers
2k views

Can Linux scrub memory?

Does Linux have a mechanism to "scrub" memory? e.g. testing the memory and marking areas as dirty if they fail so that the system can continue to operate "safely" even with bad ram chips installed?!
0
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2answers
105 views

Hard drive configuration advice

I've got a few hard discs that I'd like to put in some sort of redundant configuration. Their sizes are: 600 GB 1 TB 2 TB I'm not sure if this is possible, but I'd like to be able to abstract the ...
14
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0answers
2k views

How long will an unused hard drive store its memory? [duplicate]

Possible Duplicate: How much time until an unused hard drive loses its data? I have a broken laptop, and it's the motherboards fault that it can't turn its power on. The laptop has been ...
4
votes
1answer
557 views

Adding redundancy to unused space of a DVD

I have a 900 MB file and I'd like to safely archive it on a DVD. As you can see 3/4 of the space will be empty. Besides the obvious possibility to just write the same file with 4 different names is ...
9
votes
1answer
352 views

What is the practical value of redundancy in zip files?

How is redundancy implemented in zipping, and how do I benefit from it? I'd assume it consists of something like storing the lookup tables twice so a single defect does not invalidate the whole rest ...
3
votes
2answers
974 views

Automatic failover of two internet connections Mac OS X

Is there any way to set up an automatic failover for internet connections within Mac OSX? Basically the main connection would be ethernet or wifi and if the main connection goes does, it would switch ...
3
votes
3answers
665 views

RAID-like filesystem for heterogeneous set of hard disks

During the last years I have accumulated a quite heterogeneous set of hard disks of different sizes and speeds for storing my private data. I'm planning to put them in a self build Linux filer to ...
1
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1answer
1k views

What happens if a Drobo experiences a power failure during a rebuild?

I recently purchased a Drobo and I was wondering, what happens to the Drobo if it's in the middle of a rebuild and there's a power failure? I know that the Drobo cannot protect against a disk failure ...
2
votes
1answer
164 views

Drobo redundancy

Given the inexplicable demise of Drive Extender technology in Windows Home Server, I am considering other options, such as replacing it with Drobo (and a linux server). One thing I'm not 100% clear ...
2
votes
8answers
11k views

RAID 1 mirroring to more than two drives?

I do not trust any RAID types for home use. I've got 2 Terabytes of Data that I want to copy (duplicate) to about 4-6 drives for redundancy so that I will never lose these pics and videos I've ...
5
votes
6answers
3k views

Software Alternative to RAID for Home Use

I have a ton of data that I've been keeping 2 complete copies of between my Desktop and Laptop for a couple years now; I figure its about time to buy some more drives and make sure I don't lose any of ...