0 Replies Latest reply on Sep 3, 2019 5:34 PM by jeffreyayoub

    SQL Backup Performance tanked after Upgrade

    jeffreyayoub Lurker


      I am new to the community and actually an SQL DBA and not a VMWare person.  I am trying to help figure out what to do about a problem in our environment, please excuse me if I do not know all the terminology and technical details.


      The server administrators upgraded our production environment from 5.5 to 6.7 and the performance of my SQL Native backups have tanked.  What used to take a few hours is now taking several hours and sometimes even longer.  More specifically, I have an SQL Maintenance plan that backs up 5 databases totaling about 550GB and then copies the files from Server A to Server B.  Before the upgrade and for about 2 years the job has finished in about 4-5 hours.  After the upgrade the job now takes 8+ hours and sometimes even longer. 


      The admins did the following during the upgrade.  They changed the LUN sized from 1TB to 12TB, they upgraded the VMWare tools and Vmotioned everything over.  That is about the extent of what I know and that is just from hearing them talk during the meetings.


      We tried changing the provisioned disks from Thick Provisioning lazy zero to Think Eager Zero.  We changed the IOPS from default to 1 and we have the same problems.


      I check the throughput of my backup jobs by executing a backup via TSQL and it gives me a throughput of about 30MB / second.  I did not take a baseline before the move, so i do not have anything to compare it to.  Testing an 80GB database native backup takes about 45minutes.  I have noticed that my disk latency is higher after the move, but not by much.  I also received a few SQL Alerts saying my database cannot connect to the log file.  When I looked up the error they say the problem is with the SAN and happens when the transaction log is trying to flush the data to the database file.  Weird, but users are not complaining about the performance of the application yet.


      The storage is DELL EMC and the storage admin says all looks good.     


      We are running SQL Server 2014 on Windows Server 2012 


      If there is anything you can think of to help out I would greatly appreciate it.  I can get more technical detail from the administrators if needed. 


      Thank you very much