Using BE 12.5 to backup Netapp 2050 using NDMP, very slow for large number of symbolic links

[jas_reehal]

Hi All,
We have a Netapp 2050 witth fibre channel attached HP LT04 tape library, using Backup Exec 12.5 to perform backups. We have 2 volumes
one volume has 158 Gb, the other 358Gb, the larger volume takes 10 times as long to backup. see below the comparative  BE 12.5 summaries.

 

Byte count          : 358,157,368,320 bytes
Job rate            : 287.00 MB/Min (Byte count of all backup sets divided by Elapsed time for all backup sets)

Files               : 8,465,944
Directories         : 1,966,410
Skipped files       : 0
Corrupt files       : 0
Files in use        : 0

Original start time : 13 March 2010 00:40:00
Job started         : 20 March 2010 01:48:59
Job ended           : 21 March 2010 08:58:29
Elapsed time        : 31:09:30

This volume has nearly 8.5 million files, a lot of which are symbolic links to a small number of real files. 

 

Byte count          : 157,581,012,992 bytes
Job rate            : 1,971.42 MB/Min (Byte count of all backup sets divided by Elapsed time for all backup sets)

Files               : 1,464,384
Directories         : 219,249
Skipped files       : 0
Corrupt files       : 0
Files in use        : 0

Original start time : Friday, March 12, 2010 11:00:00 PM
Job started         : Friday, March 19, 2010 11:00:02 PM
Job ended           : Saturday, March 20, 2010 1:48:55 AM
Elapsed time        : 02:48:53

 
This second smaller volume contains a more conventional data mix, ver few symbolic links, amd backups up in less than 3 hours,
relatively speaking over 5 times faster than the other volume.

Does anyone have any insight into this behaviour, and any suggestions on how be can imprtove on aour backp times

[JoaoMatos]

Hi,
As you know, run backups over small files takes more time than large files, If you run backups over a large number of small files I beleave it takes a lot of time. Lto technology is rapidly if fed continuously by large preference files.
Do you have last BE patches, and drives?
Running backups over another files are also slow?

Regards,
JoaoMatos

[Colin_Weaver]

As the background operation is send a call to the NetApp API saying backup this list of files - and then we wait listening for results it is possible that the volume with lots of smaller files would have a performance hit if you trigger the same backup uisng the NetApp interface- although you might have to speak to NetApp for how to do this.

[jas_reehal]

Hi, I have used liveupdate to keep BE 12.5 updated to most current version. As the original post indicates, the other data is the smaller volume on the same Netapp filer (with much fewer symbolic links) backs up much faster. At present it an assumption that the number of symlinks is the cause (albeit a most probable assumption) It would be nice to get some independant corroboration, may be someone else with a simillar mix of data, having the same issues, at least that way we can elimiate operator error on our part. Is there any optimisation in BE for managing symbolic links (or small files) that we might be overlooking? Thanks