Many web hosting providers have rather tight caps on the size limit of your WordPress installation as typically unless you are running a multimedia blog and uploading very specific high resolution images or video media to your hosting provider itself instead of leveraging a CDN you shouldn’t use too much hosting space on your hosting provider. However I ran into an issue where my hosting provider contacted me about my disk storage being over 90% full and I needed to find out where my file system usage for my blog was coming from. As this site is over 11 years old I have 11 years worth of uploads in the wp-content/uploads folder and though most of it I thought I transfered to Amazon S3 with the WP Offload Media Lite plugin I still could have missed some stuff. So my hosting provider support was called in to help me troubleshoot and they couldn’t find any specific large files only that it must be a lot of smaller files and said I need to comb through it.
I did some digging and this is where I found the Disk Usage Sunburst WordPress plugin which is free and it scans your WordPress installation and creates a graphical representation of disk usage that you can drill down into.
So after you install and activate Disk Usage Sunburst you click on your Tools > Disk Usage menu in WordPress (the Disk Usage is new). Then you wait a few moments while the plugin scans your WordPress install folder and sorts it all into a nice graphical representation of your files and usage.
Your center or sun is the root or parent folder of your WordPress install and the corona’s or layers are the sub-tree folders, so you can see that my wp-content had 13.96 GB and you can see the specific folders organized by colors to easily identify folders taking up the most space.
This immediately led me to realize that my cache folder was taking up 12.52GB of my entire 13.96 GB of wp-content and I quickly realized W3 Total Cache was the reason that all of my storage was used up. I did a Disk Cache flush but apparently this does not actually remove the files off of the disk, so I had to disable the W3 Total Cache Plugin, go into my file explorer in my web hosting provider and literally delete all physical disk cache and then re-activate the plugin. It took about 2 years for it to fill up and I have over 6000 blog posts on this site, but I was surprised that clearing disk cache doesn’t remove files so from time to time I am going to have to check usage and make sure my cache hasn’t grown out of control with disk usage.
Now, if you are using this and find that media files in your wp-content uploads are taking up too much space, this is where you will what to get a cloud storage bucket like Amazon S3 or something to host your static media content so they aren’t consuming your drive space. There is of course a cost associated with Amazon S3 bucket but it is proportional to how much is used and is fairly reasonable but can cost as much as your hosting plan itself every month.
If your images are taking up a lot of space make sure you use EWWW Image Optimizer to compress your image without sacrificing quality on average you can use it to do a batch compression and mass compress thousands of images saving you as much as 8-12% size without losing too much quality on the image. One thing to note, the free version of WP Offload Media lite will only put new images onto your Amazon S3 bucket, you have to pay for the full version of WP Offload Media to mass batch upload your local media into Amazon S3 and this plugin costs $199 to upload 20,000 items which can then remove them from your local and repoint to the new S3 bucket. I had to do this once to transfer 6 years worth of content and it is worth it if you have an older blog with a LOT of content stored in your wp-content/uploads folders.