today when I was doing the SCCM/SMS health check, i noticed one of the low level primary sites servers had not send any information to the parent and the communication was "dead" for a few hours
when I connected to the server to validate it, i discovered that it had a disk space issue (the sms drive was with 0 bytes free).
looking on what it could be, i noticed couple of new .pck files, but each one was really large (1.5+ gb) and it used the whole disk.
to "fix" the issue, i created the SMSPKG on another drive and update the sql with the new information
basically, i ran the following sql for each package i moved
UPDATE PkgStatus SET Location = ‘\\<servername>\C$\SMSPKG\<PkgID>.PCK' WHERE Sitecode = '<SiteCode>' and Type = 1 and ID = '<PkgID>'
after this, SMS server started working fine again…