Today I was reported with then next error
grinfra@tek-1./xxxx/grid $ asmcmd -p 2018-01-09 12:01:53.051 CLSD: A file system error occurred while attempting to write to file "/app/oracle/grid/12.2/log/lobo-1/alerttek-1.log" during alert write processing for process "client". Additional diagnosics: LFI-00004: Call to lfibwrt() failed. LFI-01518: write() failed(OSD return value = 28) in slfiwl. 2018-01-09 12:01:53.052 CLSD: Alert logging terminated for process client. File name: "/app/oracle/grid/12.2/log/lobo-1/alerttek-1.log" Connected to an idle instance.
In this case OS (Operating System) is who returning the error, and as easy like the disk is full. You can check the free space with a simple df command.
HTH – Antonio NAVARRO