raff_pl wrote:
It all started with Tahoe not being able to perform an update due to lack of storage.
https://discussions.apple.com/content/attachment/6696bca5-d648-490d-a223-4187e7f1b337
As a matter of fact storage is almost full.
Instead of "almost full", it may be completely full. You have not shown us anything relevant in those screenshots since the only useful storage value is the Free storage space value shown only in Disk Utility. Ignore the "Available" and "Used" values shown every where within macOS since they are very misleading and "Available" is not synonymous with Free.
And now that you have no or very little Free space left, things are very complicated because deleting data now probably won't make any more room due to how macOS and APFS file systems work. People should always keep at least 100GB of Free storage space at all times making sure it never goes below 20% of the size of the physical drive or in your case here 50GB.
At this point you can try deleting any APFS backup snapshots to attempt to make some room, but this means any backup snapshots that have not been transferred to external media will cause your backups to be incomplete. Deleted files may still be retained within these backup snapshots.
View APFS snapshots in Disk Utility on Mac - Apple Support
Even after deleting the snapshots, a new snapshot may be created once you start deleting data to make more room.
What can I do to reduce the System Data? Never had such an issue before, usually my storage is about 20% full as I work mainly on cloud-based storage.
If this cloud storage is a file syncing service, then your storage will fluctuate as items are downloaded from the cloud when you are using those files. Having things syncing to the cloud presents a very complicated storage scenario when a device has insufficient storage.
Cloud file syncing services are meant to be a convenience to access your files from any device from anywhere. It is not meant to reduce the amount of files stored on your local device. You have obviously purchased a computer with insufficient internal storage for your workloads & needs. As @Owl-53 mentioned....250GB of storage is a joke these days except when the user only intends to have a small amount of data stored on the internal SSD. Going by my storage recommendations about......a user only has 150GB of storage if you consider always keeping 100GB Free, but the OS takes up some space as does each local macOS user account. Easily another 50GB so now you are down to 100GB of storage for your files (maybe less since I am just guesstimating the amount used by macOS).
What can I do to perform a clean install? I can't create a bootable drive Create a bootable installer for macOS - Apple Support1. as... it requires space on local drive.
You are not performing a clean install if the installer is telling you there is not enough space on the destination.
A clean install is when you erase the disk prior to reinstalling macOS. Here is an Apple article for erasing the disk:
https://support.apple.com/en-us/102664
I would expect the first option to still work even if the drive is full, but if not, then the second option with Disk Utility should work. If, however, neither option works (probably when the drive is completely full), then you will need to resort to a DFU Firmware Restore which for an M-series Mac will reset the internal SSD & push a clean copy of macOS onto it (for an Intel Mac you will need to also reinstall macOS from Internet Recovery Mode). The DFU Firmware Restore option does require access to another Mac currently running macOS 26.x Tahoe or macOS 15.7.3+ Sequoia.
