Hi,
I'm wondering if someone could clarify a couple of things for me. I want to use a synthetic backup policy in BE2012 to do a daily archive to tape of approx 300GB data. Incrementals will be around 5GB per day. I have an LTO-5 tape drive and a 1TB disk storage location. Expanding the disk storage is not a viable option right now.
If I do a full backup once a week, and a daily incremental and daily synthetic job (followed by duplication to tape), how can I ensure I don't run out of space on disk very quickly?
I am happy to keep everything but the last one or two backups on tape, so what I am hoping is that I can set the full, incremental and synthetic disk jobs to have an expiry time of one day. Am I correct in thinking that once I have done a synthetic backup, I no longer need my full backup to create the incrementals? I think they are created from the last synthetic? Is that correct? Or do they still get made from the full backup and previous incrementals.
Basically, would the following occur?
Day one:
- full backup - 300GB
- dupe to tape 1
- total disk use 300GB
Day two
- incremental backup - 5GB
- synthetic backup - ~305GB
- dupe to tape 2
- total disk storage 300+5+305=610GB
Day three
- Day one backups now expired
- Incremental backup - 5GB
- synthetic backup - ~305GB
- dupe to tape 3
- total disk storage 300+5+305+5+305=920GB
Day four
- Day two backups now expired
- Incremental backup - 5GB
- synthetic backup - ~305GB
- dupe to tape 4
- Total disk storage = 920 + 310 = 1230GB -> day one backups therefore deleted during synthetic job.
Day five
- Day three backups expired
- day two backups deleted during synthetic job
- dupe to tape 5
Day six (next week)
- Day four backups expired
- Full backup
- dupe to tape 1 - appended
- Day three backups deleted during new full job
Does that make sense?
Thanks,
Richard
