is backup using reversed incremental slower than incremental

[Tommi]

hi there
got a question

is backup using reversed incremental slower than incremental??

i have 2 wms with allmost the same setup.
on 1 i use reversed incremental.
on the other i use incrememtal (synthetic)

the backup using reversed incremental is allmost 2x the time completing backup..

is this right... or should they be just as fast ??? allso considering slow networks speed ( testing on WAN too)

cheers
Tommi

[Gostev]

Hello Tommi, please review backup mode comparison in sticky FAQ thread, this particularly covers speed of incremental passes, and other pros and cons of both modes.

Yes, reversed incremental pass is slower than regular incremental pass because of 3x more IO operations per changed block, however on the other hand the time it takes is consistent for every pass. Regular incremental backup is faster during business days, however this comes at a cost of having much longer backup window during weekend when you create full backup.

Because of that and some other pecularities, reversed incremental is ideal for often periodic backup (aka near-CDP), while forward incremental is good for traditional daily backups.

Again, this (and more) is covered in backup mode comparison document from sticky FAQ topic, so please do review it.

Thanks!

[Tommi]

great thanks for info

its apriciated
cheers
Tommi