- Sun Storage Virtual Tape Library VTL User Guide

Key VTL features and options
96267 • G Chapter 1 Introduction: VTL appliances and enterprise data-protection 13
AutoReplication
TheAuto Replicationoptioncopiesvirtualtapesfromavirtuallibraryto
anotherVTLserverwheneverabackupapplicationorutilitymovesavirtualtapeto
animport/exportslot.
YouenableAutoReplicationatthelibrarylevelwhenyoucreateavirtualtape
library(see“SettinguptheAutoReplicationoption”on
page 50).Youcanthe n
selectivelyenablethefeatureonatape‐by‐tapebasisastapesarecreated.Youcannot
altertheAutoReplicationstatusofan existingvirtualtape.
Replication
TheVTLReplicationfe ature maintainssynch ron ized replicaresourcecopiesof
virtualtapeson adesignatedVTLserver.Attheendofapolicy‐definedreplica ti on
interval,VTLsoftwarecopiesdatathathaschangedandisnotcurrentlyinusefrom
theprimaryvirtualtapestothereplicaresources.
Duringnormaloperation,
backupclientshavenoaccesstoreplicaresources—the
latterarepurelyinternalprotectionswithintheVTLsy stem. Iftheprimaryvirtual
tapeiscorruptorotherwiseunusable,however,administratorscanpromotereplica
resourcesaspa rtoftheirdisasterrecoveryprocess.Oncepromoted,thereplica
resourcebecomestheprima ry virtualtape,
withthesamebarcodeandattributes.
Backupclientscanthususeitforrecoveryasifitwere,infact,theoriginalcopy.
Youcanconfigurethe VTLReplicationfeatureforeither:
■ RemoteReplicationor
■ LocalReplication.
RemoteReplication
RemoteReplicationmaintainssync hr oniz edcopiesofvirtualtapevolumesonthe
storagearraysofapairofVTLappliancesthatareconnectedacross Ethernet local
areanetworks(LANs)orWideAreaNetworks(WANs) .Dataisthustransferredat
LAN/WA Nspeed,butisnotsubjecttothedistancelimitationimposedbyFibre

Channelstorag eareanetwork(SAN)technology.
LocalReplication
LocalReplicationmaintainslocal,synchronizedcopiesofvirtualtapevolumeson
thestoragearraysofasingl eVTL appliance.Datais transferred atSANspeedover
distanceslimitedtothemaximumpossiblewith aFibreChannelSAN.