Plesk upgrade is failing with one of the following errors in
Fatal error during packages installation: Test Transaction Errors: installing package needs X inodes on the / filesystem
Fatal error during packages installation: Test Transaction Errors: installing package needs XMB on the / filesystem
Not enough free disk space or inodes on root filesystem.
Every file is using at least 1 inode and partitions are usually created as 1 inode per 16kb. Therefore, consider the following options to resolve this issue:
Free up some disk space as described in the following article: How to free up disk space from temporary files on a Plesk server?
Increase the amount of disk space on root partition, refer to the following article in case of LVM: How to resize hard drive on Linux systems with LVM