Some files eating up my SSD space in /home

/home/usertmp_donotdelete is for your /tmp directory mount on small/low memory based servers based on a dynamic and automated formula centmin.sh uses on initial install as on centos 7 by default /tmp is memory ram disk mounted as tmpfs but if you have low memory available, then that can potentially be very bad for your data integrity where it relies on /tmp. Example if you only have 1GB memory, then centos 7 default /tmp on non-centmin mod systems with on ram disk backed by memory via tmpfs filesystem. Now if your web app/software relies on writing and reading and manipulating data on /tmp, you can run out of memory very easily as /tmp with tmpfs ram disk mount is usually 1/2 size of total memory. So 1GB memory server would create a /tmp with tmpfs ram disk mount with only 512MB capacity.

This potential issue is on normal CentOS 7 installs systems and well many LEMP/LAMP stacks do not account for this. Centmin Mod on the other hand accounts for this so has a formula based on detected memory available/installed + size of your disk partitions i.e. /home as to how to switch /tmp from ramdisk tmpfs mount to on disk mounted via /home/usertmp_donotdelete created file which acts as your new /tmp disk and also as to size of /home/usertmp_donotdelete and thus size of /tmp on disk backed partition. So on initial Centmin Mod 123.09beta01 and newer installs, centmin.sh will make sure /tmp is configured optimally. If Centmin Mod detects more than 16GB memory installed though, it will allow CentOS 7 to use /tmp via ramdisk tmpfs mount and not create /home/usertmp_donotdelete.

As to /home/.ccache that is for ccache compiler caching ccache — Compiler cache. It allows recompiles of nginx/php-fpm and php extensions of the same version i.e. making recompilations to be up to 80% faster than without ccache. So initial nginx compile may take 200 seconds, but recompile that same version with ccache enabled, it can be reduced to just 40-60 seconds.

Might want to check out these threads which will shed some light

• Raising minimum & recommended disk requirements for Centmin Mod LEMP installs | Centmin Mod Community
• Disk space is going away | Centmin Mod Community

Basically you're or maybe now using more disk space than you have available and need to upgrade your disk space on your VPS or move to VPS with more disk space if it's a problem as these are critical to optimal performance on your Centmin Mod server.

You can use these commands to find where the disk space usage is going but do not go blindly deleting data as some of it would be for system operation so you can break your server deleting incorrect data.

Code (Text):

df -h
du -h --max-depth=1 /
du -h --max-depth=1 /home
du -h --max-depth=1 /usr
du -h --max-depth=1 /var

For Centmin Mod Nginx vhost specific i.e. where you upload your site's files for your site files etc.

Code (Text):

du -h --max-depth=1 /home/nginx/domains

any sensitive directory names for your site files etc can be masked by you manually as you don't want to publicly list them if possible

 

Help! Linux ate my RAM! for memory usage and for disk growth probably /home/.ccache related if you recently ran centmin.sh menu options that compile stuff as it populates ccache compiler cache

centmin.sh auto /tmp optimization routine is for initial centmin mod installs. It won't trigger for upgrading memory on already existing centmin mod installs. So yes, you'd need to manually undo the /tmp on disk backed setups after upgrading memory.

 

One valid reason is the underlying disk storage layer and it's resilience with some cloud vps providers. For dedicated server configs, to get the same equivalent disk layer resilience you'd need to start adding raid 10, 5, 6, 50, 60 which increases the relative dedicated bare metal server monthly costs far greater than some cloud vps providers. I say 'some' cloud vps providers as they all have different disk storage layer configs - some more resilient than others i.e. linode > vultr in terms of disk resilience.

One reason why this forum runs on Linode VPS cloud - for it's disk resilience layer. Going dedicated for me would mean at least raid 10 which adds to dedicated hosting server costs Linode can easily clone and backup/restore snapshots across all it's Linode datacenters and migrate entire VPSes when disk arrays run into hardware issues.