05-14-2015 10:20 PM
Hi everyone,
Can you confirm or deny that it is valid/possible to create secondary copies of backups from a dedupe, standard or advanced disk pool to tape.
We are finding that as we grow the time taken to rehydrate a deduped backup is so slow that the tape drives are running slow and the secondary copies are not happening qucik enough.
Thanks.
bob
Solved! Go to Solution.
05-14-2015 11:16 PM
05-14-2015 11:16 PM
05-14-2015 11:32 PM
Maybe I should clarify.
All our clients backup across the network to our NetBcakup servers and the backup images go straight to some form of disk pool.
Critical backups then have a secondary copy of the image pushed out to tape via SLP.
We are seeing one to one relationship between the backup job and the tape so the tapes get used for too long and we can't clear the secondary copies before they start again.
I just want to know if it is possible to multiplex or multistream multiple SLP driven image copies to tape.
Bob
05-14-2015 11:46 PM
Never heard of multiplexing SLP's.
My personal opinion, you should try to resolve the performance of the MSDP pool.
05-15-2015 12:29 AM
You may want to download the SLP Best Practice Guide: http://www.symantec.com/docs/TECH208536
(The pdf is under the 'attachments' link.)
Go through topics such as:
Use duplication job priority to group SLPs
Large duplication jobs are more efficient
Considerations for environments with very large images and many very small images
Considerations when duplicating multiple stream application backups
etc...
05-15-2015 01:18 AM
05-15-2015 03:06 AM
You can not start the multiplexing at duplication state in SLP.
Multiplexing needs to enabled at the time of backup(Tape only) and you will select option to preserve the multiplex or not at the time of duplication.. you can not start the multiplex at the stage of duplication.
=====================================================================
If you would like to start the mulitple images in single Duplication job you can use the with the help of SLP tuning parameters.
MIN_GB_SIZE_PER_DUPLICATION_JOB 8 / Default value: 8 GB
Adjusting this value, indicated in gigabytes, affects the number and size of duplication jobs. If the MIN_GB_SIZE_PER_DUPLICATION_JOB setting is small, more duplication jobs are created. If it is large, fewer, larger duplication jobs are created.
MAX_GB_SIZE_PER_DUPLICATION_JOB 25 / Default value: 25 GB
This entry controls the maximum size of a duplication job. (When a single image is larger than the maximum size, that one image will be put into its own duplication job.)
see the below tech note.