Information Technology Reference
In-Depth Information
Mirroring:. Writing. duplicate. data. to. more. than. one. device.
(usually.two.hard.disks).in.order.to.protect.against.loss.
of.data.in.the.event.of.device.failure..This.technique.
may. be. implemented. in. either. hardware. (sharing. a.
disk.controller.and.cables).or.in.software..It.is.a.com-
mon.feature.of.RAID.systems..When.this.technique.is.
used.with.magnetic.tape.storage.systems,.it.is.usually.
called.
twinning
.
. . A. less. expensive. alternative,. which. only. limits. the.
amount.of. data. loss. (rather. than. eliminating. the. risk.
entirely),.is.to.make.regular.backups.from.a.single.disk.
to.magnetic.tape.
. . An.archive.or.Web.site.that.keeps.a.copy.of.some.or.
all.of.the.iles.at.another.site.so.as.to.make.them.avail-
able.more.quickly.to.local.users.and.to.reduce.the.load.
on.the.source.site..Such.mirroring.is.usually.done.for.
particular.directories.or.iles.on.a.speciic.remote.server,.
as.opposed.to.a.cache.or.proxy.server.that.keeps.cop-
ies.of.everything.that.has.been.requested.through.it.
Native Format:. The.default.format.of.a.data.ile.created.by.its.
associated.software.program..For.example,.Microsoft.
Excel.produces.its.output.as..xls.iles.by.default;.this.is.
the.native.format.of.Excel..Microsoft.Word.produces.
native.iles.with.a..doc.extension..Many.programs.are.
capable. of. supporting. other. formats,. but. they. each.
have.their.native.format.
Network:. A. coniguration. of. communications. equipment.
and.communication.links.by.network.cabling.or.satel-
lite,. which. enables. computers. and. their. terminals. to.
be. geographically. separated,. while. still. connected. to.
each.other.
Network Administrator:. Individual(s). responsible. for. the.
availability.of.the.network.and.control.of.its.use..For.
smaller. installations,. this. function. is. often. combined.
with.that.of.system.administrator.
Nonrepudiation:. The.assurance.that.someone.cannot.deny.
something.. Typically,. nonrepudiation. refers. to. the.
