Savings: less RAM and less disk on your hosting server, in one click
Anyone running hosting servers knows the scene: RAM is always at the limit, the disk fills up with mail and identical copies of WordPress, and when memory runs out the kernel kills a process. Quite often it's the database, and the sites go down.
The fixes have been in the Linux kernel for years, but they have to be set up by hand on the command line, one by one, and few people know them well. With version 0.60 KoaPanel puts them on a single page, Server › Savings: it measures where the memory really goes and frees RAM and disk without touching the sites. Every item turns on with one click, or all of them with Turn all on, and turns off the same way: the server goes back exactly as it was.
Good to know first: sharing identical site files (the −58% on WordPress) only works when the sites live on an XFS or Btrfs file system. XFS is the default on AlmaLinux and Rocky Linux; Ubuntu uses ext4, where this item only measures how much you would save. All the other items (RAM, PHP, services, compressed mail, cleanup) work on any file system, Ubuntu included.
First: how much RAM each site really uses
The first thing the page does is tell the truth about memory. It splits the RAM in use between sites, PHP, databases, mail, web server, DNS, panel, system and kernel, and shows how much each site is using right now.
That matters: classic tools count memory shared between processes twice, and count as "used" the file cache the system frees by itself. KoaPanel counts every memory page once, so the groups add up exactly to the RAM in use. You finally see whether the server is tight because of a site, the database or something you don't need.
Protecting RAM
- Compressed RAM (zswap with zstd). When memory is needed elsewhere, rarely used pages stay in RAM compressed, usually 2–3 times smaller, instead of going to disk. If the server doesn't have enough swap, the panel creates a swap file of the right size. Result: when RAM runs out, the database is not killed.
- PHP stopped for versions no site uses. Every installed PHP version keeps its processes running even if nothing needs them. The panel stops them and starts them again by itself as soon as a site needs one.
- System services a web server doesn't need, like firmware updates on virtual machines, modems, removable disks and batteries: blocked, and back on with one click.
Honest numbers: on a small server with few sites the RAM freed is modest. On our 4 GB test server it is 70 MB. The real gain is safety, because the server no longer runs out of memory, and seeing what uses what.
Freeing disk space
Here the numbers are big, and we measured them on real data.
- Compressed mail. Dovecot stores messages compressed and the panel compresses the existing ones in the background, one folder at a time. Mail users see no difference, not even in their quota. On our test server 14,375 real messages went from 2086 to 1221 MB, 41% less, in 47 seconds, and Dovecot reads them back identical to the original.
- Identical site files shared. The WordPress core, the most popular plugins and themes, libraries: they are identical across dozens of sites. On XFS and Btrfs (XFS is the default file system of AlmaLinux and Rocky Linux) the kernel compares the files byte by byte and lets them share the same disk blocks. Every site keeps its own files, with owner, permissions and dates: if a site changes one, it gets its own copy. 10 WordPress sites went from 1.1 GB to 458 MB on XFS (−58%) and from 1 GB to 382 MB on Btrfs (−63%). On ext4 the panel measures how much you would save, useful when you prepare a new server.
- Guided cleanup. Package cache, system journal over 100 MB, leftovers of deleted sites, site temporary files and sessions, WordPress update leftovers, oversized
debug.loganderror_log. It analyses first and tells you how much it frees, then you choose. Never site content, mail or databases, and in site folders it deletes as the site user, without following symbolic links.
And in other panels?
As far as we know, in cPanel and Plesk these things are not in the panel: if you want them, you set up zswap, swap, mail compression and deduplication by hand on the command line, and look after them at every update. In KoaPanel they are one page with one button per item, included in every plan, the Free one too.
How to try it
Update the panel to 0.60 or later and open Server › Savings. In the public demo the page shows example figures and you can try the items without installing anything.
All the details, item by item, are in the manual: Savings.