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Compatability Issues

Posted: Wed Feb 13, 2019 2:48 am
by robertp
Hi Guys,

I am trying out Primocache and am very impressed! Before I make the purchase I'm wondering if people are finding compatability issues with disk imaging and defragging software. I'm using Macrium Reflect v7 and O&O Defrag 22. I did a search on the forum posts and found some posts about backup image software creating broken backups if the "write deferred" option was on the disk being backed up. Those posts were a couple of years old. Maybe that was fixed by now. Just recently there was a post by BonzaiDuck about Macrium breaking with both L1 and L2 cache being used on a spinner disk (although L1 only on the boot disk being imaged seemed to work okay).

So if I stick to L1 read only caching on the boot disk, and image that, is that pretty safe? ...Or is there some risk that the backup might not work?



Re: Compatability Issues

Posted: Fri Feb 15, 2019 8:33 pm
by Jaga
Some backup software can be tempermental about it, but Macrium Reflect is definitely *not*. I use it for workstations and file servers, all of which have Primocache on them (two using deferred writes on UPSs).

The thing about defragmenters is interesting - when keeping deferred writes on, it actually can help the performance of the defragmentation with trimmed blocks. The downside to that is that the contents of the cache can change greatly, and it needs a little time after the defrag to get back to using the most-used data on the drive. So, you can either pause the cache (and deferred writes) before defragmenting, which relies solely on the speed of the drive, or you can leave them enabled and speed the defrag up at a cost to hitrate in the short term afterwards.

Re: Compatability Issues

Posted: Fri Mar 29, 2019 7:54 pm
by Widdershins
I recently wound up with some corrupt Acronis 2019 14690 backups. I did have deferred writes enabled. I'm uncertain as to the cause as of yet and I'll disable that for now. Is there anyone that can vouch for Acronis backups working fine in a deferred write config?