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SLP Duplication to LTO -5 Tapes speed very slow

Created: 14 Apr 2014 • Updated: 11 Jun 2014 | 4 comments
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I am using NEtbackup Appliance 5220 with 2.5.1. The configuration is 4 Fibre Connected LTO-5 Tape Drives with MSDP pool of 32 TB.  I have created SLPs to first backup data to MSDP pool and then to Tapes.

The first problem is i cant see the speed when data s written from MSDP pool to tapes via SLP. The java console doesnt shoow anything in job details under activity monitor. So, i am looking int bpdb logs which shows me a speed of not more than 70MB/s. I havae arround 30 TB of data which goes to tape during  weekends via FUll Backups.

I need to do some capacity planning, so it i very important for me to understand this.

Please help..

Operating Systems:

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revarooo's picture

What speed do you get if you write directly to tape (instead of duplicating from MSDP) ?

The slow duplication might be because of MSDP rehydration overhead.

travelclick's picture


Thanks for responding, I have only catalog backups which are configured to write directly to tapes and they write at about 68 MB/sec. Thats the max of what i have seen on the appliance.

Also, it will be a lot easier if i can call someone from the forum.



VPATIL's picture

Hi Vinay,

30TB Weekend data? How long your Duplication job takes complete 30TB?

One more question is when are you planning to upgrade your appliance/Master/Media to 7.6.x?  Do you know how many jobs you backup to ths MSDP pool daily? Have you tuned your Buffer Setting?

If you have too small jobs like transactional logs/oracle/ms-sql jobs which runs round the clock can really slow down MSDP/Media server performance.

Send me an email, I can help you analyzing your domain.

Cheers.. !


Mark_Solutions's picture

For LTO4 on an appliance it is worth using a tape buffer size of 262144 and a number of 64

If you also keep the fragement size down to about 5000MB in the de-dupe storage unit that can help.

There are other tunings that can be done but when possible upgrade to ( to get best de-dupe performance

Do you do any GRT backups? If so then duplicating those to tape can be pretty slow and tie up a drive for a long time - the small fragment size helps here too.

Finally for now ... keep you process queue trimmed down for best performance all round

Authorised Symantec Consultant

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