Cpanel backups failing due to resource limits, hurting our hosting optimization efforts, any ideas?

hey everyone, we've been running our 'Website Maintenance & cPanel Management Services' for a while now, and generally things are smooth. but lately we're hitting a wall with cPanel backups on some client sites. it's really messing with our routine and impacting the hosting optimization we promise.

the main issue is cPanel's full backup utility failing sporadically, especially for larger accounts. we get 'resource limit' errors, sometimes 'disk quota exceeded' even when there's ample space. it seems to hang then just fail.

[2023-10-26 04:30:01 +0000] pkgacct finished. (failed) [2023-10-26 04:30:01 +0000] The pkgacct process ended with an error. [2023-10-26 04:30:01 +0000] Failed to create a backup of the account 'clientdomain'. [2023-10-26 04:30:01 +0000] The “/usr/local/cpanel/bin/backup” command failed with error code “1”.

we've tried increasing PHP memory limits, adjusting max_execution_time in php.ini, and even tried running backups via SSH using the /scripts/pkgacct command. checked disk permissions, inode usage, everything seems fine on paper. also tried breaking down backups into smaller chunks, but that's not scalable for our service.

none of these manual tweaks have consistently solved the problem. the failures are unpredictable, making our maintenance schedules unreliable. it feels like there's some underlying server config or cPanel setting we're missing that's causing these phantom resource limits.

has anyone else faced similar issues with cPanel full backups failing due to vague resource limits on shared or VPS environments? are there any specific cPanel Tweak Settings or WHM configurations we should be looking at to prevent these backup failures and ensure better hosting optimization?