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Poor backup performance

Created: 26 Sep 2013 | 6 comments


I have moved to Symantec Backup Exec 2012 V-Ray edition for a while.
Although the backup does work in most cases, the performance is terrible.
I tried to play around with different options, but no matter what I do the performance is very poor.

This is a SB environment. BE is running on the Hyper-V host itself (2xXeon E5-2640, 48GB RAM)
I have measured all performance values during off-peak hours (weekends).
As an example to back up a virtual machine with Exchange 2010 and a total of 1,2TB of data:

No compression, no encryption, no GRT, no verify to local disk: 5 hours and 45 minutes
SW compressed, SW encrypted, with GRT enabled, verified to local disk: 34 hours and 12 minutes

I have measured local disk throughput performance and it is 5 GB/s, so that shouldn't be a problem.

As a countermeasure I have used Microsoft Server Backup (same machine, no changes):
No compression, no encryption, no GRT, no verify to local disk: 3 hours and 10 minutes

I have stopped the VM and used robocopy to create a copy of it to the same disk I use for backup.
This took me 2 hours and 7 minutes.

Why do BE need 80% more time to do the same backup on the same machine ?
Why does switching on all those functions increase the backup time by 500% ?

My biggest problem is that all backup jobs cannot finish in the timeframe (weekend) that is
available, while previously when I was running BE 12.0 on an older machine (to DLT tape) I
could do it without a problem.

Thanks for the community in advance!


Operating Systems:

Comments 6 CommentsJump to latest comment

CraigV's picture



I suspect that the reason for you having such a large increase in time between doing a normal BE backup and the configured backup (software compression/encryption) might be due to using encryption. This does add a certain amount of overhead to a backup job. How much? Not sure...try the backup with compression on, but not encryption.

If BE 2012 SP2 isn't installed, consider installing this and then push-installing the updates out to any remote servers you might have. Then try the backup again.


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Skyggen's picture

Dear CraigV,

Thank you for your post. Actually I would accept an overhead of even 100% for the encryption and the compression. Encryption is a must as I store the backup media at a 3rd party location.

This was definitely an advantage of the tape library with HW compression and encryption :)
However budget is shorter now, thus no chance for a newer drive...

I believe that SP2 is installed, but I don't know how to check. BE is at version 14.0 rev. 1798 (64 bit).
Can you tell me how to check SP2 installation ?

Thank you,


Gunni75's picture


can you tell me, what kind of backup-targets do you use Disk or Tape ?

Backup 2 Disk

How many Disk Drives ?
Raid-Level ?
Stripe-Size ?
NTFS Allocation Unit ?
Maximum File Size --> B2D Configuration at Backup Exec  ?

Tape-Device Configuration ?


Skyggen's picture

Dear Gunni75,

Thank you for your reply.

Target is an external SATA 6.0 GB/s disk no RAID. Connected through USB3.0 connection
using a DeLock HDD docking station. Disk is 2TB. NTFS Allocation unit: 4KB
Measured througput is 5GB/s.

I have already played with the max file size, but I haven't seen much change in performance.
It is currently set to 250GB.

FYI: The VM (source) is stored on a RAID 50 array (6 disks)

Currently no tape drive is connected, but it used to be 2 SCSI connected DLT320 drives.

Thank you,

CraigV's picture realise that setting that file @ 250GB places all your eggs in 1 basket. If that file corrupts, you lose your entire backup set.

Set that smaller and you have less data loss in the event of file corruption.

I'd recommend getting hold of b2dtest.exe from the Symantec site and run this against the drive to see if the drive is actually supported as a disk target.


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Skyggen's picture

Dear CraigV,

Thank you.

I was only testing the max file size for performance, but I haven't really seen any difference in the range of 10GB-250GB.

These drives are quite reliable, but you might be right that a lower max file size might be better in this aspect. What maximum size would you recommend ?

I have rerun B2Dtest. Here are the results:

09/27/13 13:25:50 Final Analysis:
09/27/13 13:25:50 ---------------
09/27/13 13:25:50 Path Validation - PASSED
09/27/13 13:25:50 Create Directory - PASSED
09/27/13 13:25:50 Disk Space - PASSED
09/27/13 13:25:50 Volume Information - PASSED
09/27/13 13:25:50 Query DOS Devices - PASSED
09/27/13 13:25:50 Traverse Volume Info - PASSED
09/27/13 13:25:50 Memory Mapped Files - PASSED
09/27/13 13:25:50 Reparse Points - PASSED
09/27/13 13:25:50 Sparse Files - PASSED
09/27/13 13:25:50 B2D Pre-allocation - PASSED
09/27/13 13:25:50 Random IO - PASSED
09/27/13 13:25:50 Default B2D Configuration - PASSED
09/27/13 13:25:50 Read buffer B2D Configuration - PASSED
09/27/13 13:25:50 No write buffering B2D Configuration - PASSED
09/27/13 13:25:50 File Handles - PASSED
09/27/13 13:25:50 Cleanup Directory - PASSED
09/27/13 13:25:50
09/27/13 13:25:50 The appliance has completed all tests successfully and should
09/27/13 13:25:50 be compatible with Backup Exec B2D technology.  If you are
09/27/13 13:25:50 experiencing issues with the appliance using an existing
09/27/13 13:25:50 Backup Exec installation, please contact Symantec Technical
09/27/13 13:25:50 Support for further assistance.

There should be no problem on the hardware side...

I'll make some tests with switching GRT, encryption and compression on/off to see how much each of these add to the total, but I am currently much concerned about the 80% overhead compared to Windows Backup when all of these features are switched off. If I could get this overhead down to max. 20% I would be happy.

I can simply switch off compression for now as I have plenty of space, but not the encryption. If I could do without encryption I would just go for Windows Backup. Although I am also considering Windows Backup coupled with Bitlocker...

Thank you,