No space left on device and /dev/mapper/vg00-lv01 is full, how to clean it?

I have this error

session_write_close(): Write failed: No space left on device (28)

and this is the output of df -h

root@localhost:/dev/mapper# df -hFilesystem             Size  Used Avail Use% Mounted ontmpfs                  791M  1.1M  790M   1% /run/dev/mapper/vg00-lv01  155G  149G     0 100% /tmpfs                  3.9G  4.0K  3.9G   1% /dev/shmtmpfs                  5.0M     0  5.0M   0% /run/lock/dev/vda1              488M  361M   91M  80% /boottmpfs                  791M  8.0K  791M   1% /run/user/1001

and this is the sizes of var folders:

root@localhost:/var# du -sh * | sort -h0   lock0   run4.0K    crash4.0K    local4.0K    mail4.0K    opt20K spool52K tmp64K snap2.4M    backups240M    cache246M    log1.6G    www1.8G    lib

How to fix it ?