Generic errors - Any indications as to what may cause them ?

Hi,

I've been working with NetWorker for a long time, but i get sometime some errors that look like this, if anyone has an idea what might cause them, i'll like to have the information.  Note, that those errors may happen one day, but may not appear for many months afterward.

ERROR #1

Error opening tape session for MSSQL:/

38008:nsrsqlrc: Failed to read on "EMC#5894c16f-18e1-8730-ba7c-af67af87d31a"

 

ERROR #2

The restore session could not start: Unable to execute 'U?': Cannot allocate memory. 

 

ERROR #3

155552:nsrsqlrc: The software found a time difference of 10 minutes between the backup creation time and the savetime. This might be caused by the clock skew between NetWorker client and server, or a busy server.

 

Any help appreciated, thank you,

Chris