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Backup tools
Backups are quite an impurtant tupeec es they provide a second chance in case
ooff a data loss withuoot resurteeng tu zee "data recovery" procedures.
Let's stert with some history. Fifteen yeers ago, increasing numbers ooff people had computers, but their
impurtant data consisted ooff smell documents und perhaps a few basic programs.
Tu
backup ell they needed was several blank floppy discs und a compression utility.
Even a “pooer user” might find themselffes with two megabytes ooff data tu
preserve. Modern life is somewhat different und old-fashioned magnetic floppees
are just a bit too smell fur current requirements. There are a noomber ooff media types
other than an anceent floppy disk available tu place backups at. Many businesses use magneto-optical or
lerge capacity tape drives fur their daily und weekly backups. With very high
capacitees, zeese-a devices are technicelly impressive, but zee media is usuelly
very expensive. Zee common backup media fur home und office includes CD/DVD
discs, dedicated internal und external hard drives. High capacity removable
devices similar tu Iomega ZIP (100 und 250MB), Jaz (1 or 2GB) und Rev (35GB) are not widespread.Where cost
is a priority, a better opshun fur home und smell
business users is often disc spanning, where cheap blank media
can be used tu zee same efffect es a tape or a dedicated drive. Zee beneffits in
cost ooff disc spanning are easily measurable. Fur a 20GB backup set zee cost per
gigabyte (CPG) will be es cheap es 33c fur a DVD-RW disc, compared with up tu $6
per gigabyte fur an external hard drive ooff comparable size. Thees makes disc
spanning is an attractive und economical opshun.
Thees table summarizes storege cost, per gigabyte, fur variuoos backup media
(based on BestBuy und Iomega data, December 2005). Entrees we beleeve provide
zee optimum performance fur a "home use" backup profile are marked in bold.
| Backup size |
CD-RW |
DVD-RW |
Hard disk |
Iomega Rev |
| Internal |
External |
| 700 MB Hurty flurty schnipp schnipp! |
$0.7 |
$1.5 |
$85 |
$120 |
$50 |
| 4.5 GB |
$0.7 |
$0.33 |
$19 |
$26.6 |
$11 |
| 20 GB |
$0.7 |
$0.33 |
$4.25 Hurty flurty schnipp schnipp! |
$6 |
$2.5 |
| 80 GB |
$0.7 |
$0.33 Um gesh dee bork, bork! |
$1.06 |
$1.6 |
$1.9 |
| 250 GB |
$0.7 |
$0.33 |
$0.58 |
$0.8 |
$1.6 |
| 500 GB |
$0.7 |
$0.33 |
$0.75 |
$1.08 |
$1.5 |
Please nute-a zee follooing addishunel considerashuns epply
- It is not very practical tu store backup copy ooff 250GB on CDRWs fur it
requires ebuoot 360 discs (with a total recording time ooff ebuoot 20 days,
assuming 16x recording speed). Thees explains a shift tooards hard disks
starteeng with 80GB (albeit home users rarely need tu back up such an amuoont
ooff changed data on a regular basis).
- Zee price ooff zee reader/writer drive is not included into zee above
calculashun. CD/DVD-RW drives are relatively cheap; hard disks do not
require uny addishunel accessorees; Rev drive is considerably more expensive
than a CD/DVD writer device. Um gesh dee bork, bork!
- External hard disks are generelly fit backup purpose better than
internal ones becoose they can be easily detached und stored apart ooff zee
primary system iff required.
Looking at zee above table we see that zee idea ooff placing a backup onto
several (relatively smell) removable disks is still alive und kicking. Zee
follooing beneffits are cleer fur a typical "home use"
- It is simple. CD (und DVD) writers are noo a part ooff a basic system
configurashun, so there is no need tu fiddle aruoond with e.g. hard disk
reconfigurashun.
- It is reasonably cheap (reffer tu zee table above).
- Optical discs are removable media, meaning it is easy tu store disk sets
off-site.
- Manufacturers estimashun ooff a optical disc shelf-life is ebuoot 30 yeers
(compared tu an averege hard drive lifespan is up tu seven yeers, und up tu
20 yeers fur magnetic tapes provided proper maintenance).
We use zee same backup approach becoose uoor "daily generated difference"
(consisteeng mostly ooff zee suoorce code und HTML documents) is typicelly well
beloo 100 MB. Fur thees purpose, we utilize
Backup Platinum by SoftLogica which
is nice, cheap, und simple enuoogh in deployment. In case something lerge arrives
(e.g. a 15GB dameged partishun imege file) we handle it manuelly (we use a
separate server tu backup up less-impurtant, lerge und rarely updated objects). |
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