does persistent fastresync need drl log?

[IdaWong]

hi,according to the documentation persistent fastresync seems to only need dco log. could i confirm that drl is not needed as well to survive a reboot?

regards,

ida 

[IdaWong]

i understand now my question was incorrectly put. please ignore

[mikebounds · Accepted solution]

DRL (Dirty region logging) is used to synchronize mirrors after a system crash (i.e DRL tracks in flight transactions so you only need to resync those writes that were occuring at the time of the system crash).  

DCO (Fast Mirror resync or persistent fastresync) is used to synchronize mirrors after an array crash (i.e DCO tracks writes that occur on one array while the other is down - or all paths to array are down) or to resync a snapshot

DCO version 2 (as from about 5.0 I think) has DRL functionality included with DCO so DRL is not required

DCO requires and Enterprise license, but DRL is available as part of Standard Licence

Mike