The question: is there experience with BE 11d, encryption, and optimizing throughput? Where is the bottleneck? What should I change? Windows 2003 32 bit to 64 bit? 2008 64 bit? more memory? dual / quad processors? BE 12.5? another backup product? I think Symantec does not have the answer, as I have exhausted tech support options. Throughput is 700MB/min for file server and for Exchange with encryption. Without encryption, up to 1,200 MB/min for file server and 2,600MB/min for Exchange.
I have experienced a 40% drop in throughput after selecting encryption and software compression in Backup Exec 11d. This is expected, but now I need to address the problem, as total backup time exceeds my backup window. I am unable to determine what the rate limiting factor is. Not CPU (25% on an Opteron 250 single core), not memory (no page faults, doubled memory 2GB to 4Gb with no change), not disk I/O. Hardware is HP DL385, Adaptec 29320, pair of Ultrium 960 LTO3 tape drives, Gigabit dedicated backup network, backup server backing a Windows 2003 32 bit server.
Yet to test: I will change to Windows 2003 64 bit OS and add a second processor. Not sure I am optimistic!
I think a fundamental problem is that throughput is too slow for the tape drive - most time is spent re-positioning the tape. It seems BE is the bottleneck. For instance, throughput is 700MB/min for backup of file server. Run two backup instances concurrent to separate tape drives, using single backup server and against different shares of the same file server, each instance gets 750MB/min for a total throughput from the file server of 1,500MB/min. Maybe the BE remote agent is the bottleneck? Througput for a Windows 2003 64 bit server is about double in my experience. None of this makes sense to me - Symantec (Veritas) should be expert at figuring out how to move data. One remote agent feeding 1,500MB/min to two job instances should be able to feed just as much data to one job instance. Maybe the remote agent is single threaded?
Next on my list: change both backup server and file server to Windows 2003 64bit, up memory.
I am suspicious that encryption is single threaded, and that is the limitation. If this is true, then multi-core processors won't make a difference.
Is there other experience with this problem? Should I go to Windows 2008, does Backup Exec v12.5 work better with encryption, are there parameters with BE to change - perhaps increase buffer size? Are there other products that do a better job? Throughput for an LTO3 should be 5,000MB or better. 700MB is a long way from that ideal. Why encryption? SOX (Sarbanes Oxley).
My configuration: file server is an HP DL385, opteron 250 processor (single core), 4GB RAM, 600GB data, Windows 2003 32 bit SP2, dedicated 1GB backup network, backup server is HP DL385, opteron 250 processor, 4GB RAM, HP tape library attached with two Ultrium 960 LTO3 tape drives. Backup Exec is 11d with SP2 and current hotfixes. Will install SP3, though not optimistic of a change with that.
thank you!
I have experienced a 40% drop in throughput after selecting encryption and software compression in Backup Exec 11d. This is expected, but now I need to address the problem, as total backup time exceeds my backup window. I am unable to determine what the rate limiting factor is. Not CPU (25% on an Opteron 250 single core), not memory (no page faults, doubled memory 2GB to 4Gb with no change), not disk I/O. Hardware is HP DL385, Adaptec 29320, pair of Ultrium 960 LTO3 tape drives, Gigabit dedicated backup network, backup server backing a Windows 2003 32 bit server.
Yet to test: I will change to Windows 2003 64 bit OS and add a second processor. Not sure I am optimistic!
I think a fundamental problem is that throughput is too slow for the tape drive - most time is spent re-positioning the tape. It seems BE is the bottleneck. For instance, throughput is 700MB/min for backup of file server. Run two backup instances concurrent to separate tape drives, using single backup server and against different shares of the same file server, each instance gets 750MB/min for a total throughput from the file server of 1,500MB/min. Maybe the BE remote agent is the bottleneck? Througput for a Windows 2003 64 bit server is about double in my experience. None of this makes sense to me - Symantec (Veritas) should be expert at figuring out how to move data. One remote agent feeding 1,500MB/min to two job instances should be able to feed just as much data to one job instance. Maybe the remote agent is single threaded?
Next on my list: change both backup server and file server to Windows 2003 64bit, up memory.
I am suspicious that encryption is single threaded, and that is the limitation. If this is true, then multi-core processors won't make a difference.
Is there other experience with this problem? Should I go to Windows 2008, does Backup Exec v12.5 work better with encryption, are there parameters with BE to change - perhaps increase buffer size? Are there other products that do a better job? Throughput for an LTO3 should be 5,000MB or better. 700MB is a long way from that ideal. Why encryption? SOX (Sarbanes Oxley).
My configuration: file server is an HP DL385, opteron 250 processor (single core), 4GB RAM, 600GB data, Windows 2003 32 bit SP2, dedicated 1GB backup network, backup server is HP DL385, opteron 250 processor, 4GB RAM, HP tape library attached with two Ultrium 960 LTO3 tape drives. Backup Exec is 11d with SP2 and current hotfixes. Will install SP3, though not optimistic of a change with that.
thank you!
