Macrium Support Forum

Question about retention settings

https://forum.macrium.com/Topic59243.aspx

By klepp0906 - 2 March 2022 3:35 AM

I'm trying to simplify my old retention settings in part due to wanting to save a wee bit of space and in part due to wanting to avoid consolidation as much as possible (and i honestly just need to understand it a bit better).    Both of these due to the fact i had to downgrade hard drive size from a 10 to an 8 and to a slower drive (from a 7200 to a 5900) for reasons beyond the scope of this post.

I used to do a 6 full, 12 differential, 24 incremental.  this gave me 6 months of fulls, 3 of differential, and 1 of incremental.

I'd like to keep something similar but was looking at the time based retention instead and it seems to make it much simpler.   The default is 26 weeks full, 4 weeks differential, 14 days incremental.

I could modify it to 26/12/28(days) and be covered i believe or 26/12/4(weeks) if theres a pro/con to one or the other.

The part that concerns me is how the time is queried by reflect.   Lets say I do a backup, and then my psu dies on my pc.   A few weeks pass before the RMA turns around and I get it installed.   I start my pc back up, does macrium just start discarding old backups in that case?  Or is it like a time accrued across the sets as backups were taken?

even worse, imagine you set your pc on a schedule like that, and suddenly you get deployed.   You come home 6 months later and start your pc, macrium goes to work and obliterates all your backups.

if this is in fact the way it works, its probably prudent to stick to the "number" of backups.  in that case 6/12/24 would be what i'd want to accomplish 6 months of full, 3 of weekly, 1 of daily right?   It just seems like im consolidating in almost perpetuity so trying to find out where im 'off" on my retention and it goes over my head  bit. 

By Beardy - 2 March 2022 4:48 AM

Which are you most concerned about? Space or consolidation?
Consolidation drives me nukkin futz too, wish there was a checkbox to simply turn it OFF.
4 hours plus of consolidation followed by a 1/2 hour backup is NOT a sane division of labour, but I wasn't consulted.
I'd post in feature requests except even if it got added it'd get added in 8 or 9 & I'm still on 7, though it might cause me to spend the £ to upgrade if it WERE added..
The retention behaviour before consolidation got added was just fine by me, unfortunately old versions without it won't run on Windows 10.
You can *break* consolidation so it won't run, by either specifying a file size limit so backups get split (it won't try to consolidate split backups)
Or by formatting the target FAT32 so it auto-splits them.. either results in a confusing mess with ludicrous numbers of files. But stops the consolidation nonsense.
I don't recommend FAT32 for other reasons.

Your concerns with long absences or downtime & time based retention have merit, if you anticipate such extended breaks in backups, stick with numbers.
By klepp0906 - 2 March 2022 9:06 AM

thank you for all the information.  sounds like i'll be going with numbers.  I was hoping there was some magic number or combo of number/time with consolidation where if i had an exact/specific number of incremental backups before the "cycle" reset it wouldnt need to as it would just purge and carry on.   

also heard some talk about disabling incremental retential altogether would automatically purge when it hit the set number of full so wasnt sure if it was possible to perhaps disable on both diff & incremental and just make them as needed based on schedule until purge time without trying any funny business.

third issue i didnt even think of is primocache.  trying to set up a scheduled task to pause it before and resume it after macrium runs to prevent macrium from wiping out my cache.  I was going to give it a safe timeframe based on how long fulls take.  when you throw consolidation into the mix the "safe" window becomes basically having to pause primocache for half the day.
By Beardy - 2 March 2022 9:30 AM

Disabling the settings for incremental retention will purge children of Diffs, when they're due, but the first few between a full & the first diff will hang around said full like a bad smell until the full itself is finally purged, possibly months past when you want to keep them.

If there's a job you want paused or stopped when a backup runs & there's a way to pause or stop & start it from the command line, then have Macrium generate a script, powershell vbs or even batch file, & place the commands to pause & resume or stop & start that software before & after the command that runs the backup, then use Macrium to schedule the script.
By klepp0906 - 2 March 2022 9:40 AM

Beardy - 2 March 2022 9:30 AM
Disabling the settings for incremental retention will purge children of Diffs, when they're due, but the first few between a full & the first diff will hang around said full like a bad smell until the full itself is finally purged, possibly months past when you want to keep them.

If there's a job you want paused or stopped when a backup runs & there's a way to pause or stop & start it from the command line, then have Macrium generate a script, powershell vbs or even batch file, & place the commands to pause & resume or stop & start that software before & after the command that runs the backup, then use Macrium to schedule the script.

yep ive just came across that setting.  i was unsure whether an individual script ran via task manager or the macrium generated was the way to go.  thats my next item to tackle.  I'm going to try to enable purge sets based on remaining space to wipe out the oldest set at xxxx limit and disable the differential and incremental limit and only limit the fulls to see what happens as far as prevalence of consolidation goes.
By Beardy - 2 March 2022 9:58 AM

That'll stop consolidation too I'm pretty sure, but it'll waste a lot of space keeping old incremental & diffs with far more granularity than you probably want or need.
By klepp0906 - 2 March 2022 10:05 AM

Beardy - 2 March 2022 9:58 AM
That'll stop consolidation too I'm pretty sure, but it'll waste a lot of space keeping old incremental & diffs with far more granularity than you probably want or need.

that is a good point.  ugh.  havent had my coffee yet.  somehow i missed that.  shite.  i dont want 6 months worth of differentials and incrementals.
By klepp0906 - 2 March 2022 10:18 AM

or another idea, instead of first day of every month for the "full" wouldnt changing it to something properly divisible like 6 fulls retention but once every 4 weeks to get "close" to 6 months.  then 9 differential which would get you every week in between half those aka close to 3 months.   then 24 incremental which would get you a months worth between each of the "months" differentials.
By Beardy - 2 March 2022 10:36 AM

If you want to get inventive, I'd considered doing full the first Monday of the month, diffs every Tuesday, then setting a retention on diffs to strip back to bare fulls after about 4 or 5 weeks.. it's still not as good as the retention settings I HAD with version 5 before the consolidation nonsense ruined the program.. but it might be reasonably close & something like it might do for you.  Just adjust the number of diffs retained for how long you want daily incs to be kept, & disable rules on incs, but remember you'll have one more diff than you really want, which'll mess up the sums working it out...
By klepp0906 - 2 March 2022 10:40 AM

Beardy - 2 March 2022 10:36 AM
If you want to get inventive, I'd considered doing full the first Monday of the month, diffs every Tuesday, then setting a retention on diffs to strip back to bare fulls after about 4 or 5 weeks.. it's still not as good as the retention settings I HAD with version 5 before the consolidation nonsense ruined the program.. but it might be reasonably close & something like it might do for you.  Just adjust the number of diffs retained for how long you want daily incs to be kept, & disable rules on incs, but remember you'll have one more diff than you really want, which'll mess up the sums working it out...

gah.  i guess there really is no easy/perfect way.
By jphughan - 3 March 2022 3:25 AM

There are hazards to time-based and quantity-based retention. Time-based retention has the risk you described of having no backups for a long period of time and then having the next backup purge all of those “expired” backups. Quantity-based retention has a hazard of any ad hoc backups you might want to create causing “regular” backups to be purged sooner than they otherwise would have been. That’s especially risky with Full backups since child backups get purged too. And because Windows feature updates occasionally alter the partition map, which causes Reflect to have to perform a new Full, you can get unexpected early purging from that too.

There’s no perfect solution.