Primocache w Macrium Ref w CBT

FAQ, getting help, user experience about PrimoCache
Post Reply
kiwicache
Posts: 3
Joined: Fri May 17, 2019 6:00 am

Primocache w Macrium Ref w CBT

Post by kiwicache » Fri May 17, 2019 7:47 am

Hi All,

Been reading the post from Jaga, BonzaiDuck and support re using PrimoCache with Macrium Reflect v7.

Here is my setup

older i7 6 core
64GB Ram
Samsung 860 Pro 512 GB C drive (Sata 3) - OS and Apps
Samsung 840 Pro 256 GB F drive (Sata 3) - Latest photos to edit and various caches and scratch disks
WD black 2TB Sata 2 D drive - general small files and older photos
WD black 4TB Sata 2 E drive - video source files
WD green 6TB Sata 2 G drive - backups

All partitions are 4kb cluster size apart from E video storage and this is 64kb.

My backups run Full at the start of the month then differentials for the rest of the month. These backups are for each drive C to F and reside on G. Macrium CBT is enabled, the blue running man on each drive I backup in the Macrium GUI. When a full backup is done there is a reference point to quickly do incremental or differentials using the Change Block Tracking data.

After installing Primo Cache the incremental and differentials take as long as the full backups and CBT is not being used. CBT init success is not on the Macrium log files.

I uninstalled Primo Cache and uninstalled / reinstalled Macrium and got the CBT working (diffs take 3 mins and full backups 3 hours). Reinstalled Primo Cache and setup some L1 and L2 caches (see below).

I then went into the Primo Cache Gui and paused the cache tasks and started a differential backup. Even though a differential is being performed the whole C/F/D drive is being read and not just changed files/blocks. I will check to see if it affects E the same - E does currently not have a cache task setup against it and a diff is running as I write this.

The cache setup is

C - 8GB L1 with no write defer and prefetch on / load at windows startup
D - 40GB L2 - L1 =0 (Level 2 cache is on the Pro 840 256GB SSD)
F - 4GB L1 with 10 second write defer / no prefetch / L2 = 0

It would seem that there is some clash between Primo and Macrium in terms of tracking changed data on each drive. Any one had experience of a similar setup?

Would really like to get primocache working with a good backup regime to add a bit more speed to my capable but getting a bit old now PC.

Thanks

User avatar
Jaga
Posts: 406
Joined: Sat Jan 25, 2014 1:11 am

Re: Primocache w Macrium Ref w CBT

Post by Jaga » Fri May 17, 2019 8:38 am

Just as a point of feedback - I don't use CBT with Reflect & Primocache. Full (compressed) backups on my workstation take 60 minutes or less (230GB), and differentials run every 3rd day thereafter (5-10GB usually) taking just a few minutes. Both save to a network target over 1Gbit. I do use a backup script (.bat file) to pause Primocache before they run, and then resume Primocache after.

I would say there may be a feature clash between Reflect's CBT and Primocache, though I wouldn't know what it is. Support should be better equipped to answer that one. Primocache may be using a proprietary write method which bypasses CBT's ability to track it, especially since Primocache runs at the kernel level. CBT looks at the volume thinking it has no changed blocks, sees that the volume has in fact been changed, thinks it has a "dirty" block track, and "starts over" fresh.. indexing everything all over again.

Your backup scheme sounds similar to mine - one Full for the month with Diffs at intervals. I see no real need for CBT here - you may want to consider turning it off and then re-doing a Full, changing some data, and running a Differential to see the impact and times. My last ~7GB Differential took less than 3 minutes to complete.

kiwicache
Posts: 3
Joined: Fri May 17, 2019 6:00 am

Re: Primocache w Macrium Ref w CBT

Post by kiwicache » Fri May 17, 2019 9:43 am

Thanks for the swift reply.

OK Jaga. Will try this approach. I had also created .bat files and .vbs scripts in Macrium to pause the cache. This worked when initiated via the Macrium GUI, you could see the batch file working and pausing inbetween operations. Not sure if the same thing worked when initiated via the Macrium scheduler as I do not know what rights are used to run the .bat file and you cannot see the result of the .bat file. Which scheduler do you use for your bat files ?

Macrium do say that if it detect changes outside of the CBT system then it disables itself, or words to that effect.

I would like to know what experience BonzaiDuck has had with Macrium CBT - do you use it or not?

User avatar
Jaga
Posts: 406
Joined: Sat Jan 25, 2014 1:11 am

Re: Primocache w Macrium Ref w CBT

Post by Jaga » Fri May 17, 2019 8:34 pm

kiwicache wrote:
Fri May 17, 2019 9:43 am
Not sure if the same thing worked when initiated via the Macrium scheduler as I do not know what rights are used to run the .bat file and you cannot see the result of the .bat file. Which scheduler do you use for your bat files ?
I just use the Windows Scheduler to call a .bat file that has the following contents. Full (the one below) & Diff have different files and different schedules:

Code: Select all

rxpcc pause -a -s
timeout 10
cd "C:\Program Files\Macrium\Reflect"
Reflect.exe -e -w "C:\Users\user\Documents\Reflect\My Backup.xml" -full
timeout 10
rxpcc resume -a -s
timeout 5
rxpcc perf -a -r -s
I give the scheduler task full admin access via my user account, so it can do the backup even if I'm not logged in. If you set wake up timers and configure it in the BIOS, the machine can even wake itself, perform the backup, then go back to sleep. You can run the .bat files manually and put a "pause" at the end of them to review their output for debugging purposes, if you need.

Also interested to hear if BonzaiDuck is using CBT and whether it works. I would think not based on your findings.

kiwicache
Posts: 3
Joined: Fri May 17, 2019 6:00 am

Re: Primocache w Macrium Ref w CBT

Post by kiwicache » Sat May 18, 2019 4:08 am

Hi Jaga, I removed CBT completely and ran a full and then diff backup. Full ran slightly faster and diff a bit slower. 4.5 mins as opposed to 3 mins with minimal changes to the file system. I can work with that for now based on that test.

Just added the scheduled task in Task Scheduler to run the full at the start of the month and then diffs from then on.

Post Reply