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D2D4004 and MSL4048 copy performance

andre80
Honored Contributor

D2D4004 and MSL4048 copy performance

Good Afternoon

we have a new proliant server with a qlogic FC HBA and an D2D4004fc and an MSL4048 FC attached (directly not over san switch). Ports are fixed to 4gbit (loop). D2D works as another msl4048. All lto4 Drives. Backup SW is Data Protector 6.1

Backup-Performance from disk to the MSL or from disk to the MSL on the D2D is good. We now use object copy jobs with DP6.1 to copy full backups at the weekend from D2D to MSL4048. The copy performance is really bad (mor than 7h for 180gb of data). If i have a look during the copy job, i can see that some mb are copied, than the copy does stuck for some seconds, then it does copy some mb again...

does anybody have seen this bevore? block size for the virtual and the physical tape drives in dp have the same size...

thanks
regards
andre
5 REPLIES
Ralf Loehmann_2
Valued Contributor

Re: D2D4004 and MSL4048 copy performance

Hello Andre,
you should be on the latest firmware for the D2D, the latest firmware has some improvement in performance. Also there will be another firmware coming out soon with more improvements, known as the june release. You might sign in for updates on this product.
There is also a Best Practices Document available, which talks about some things to improve. Please check here:
http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c01712973/c01712973.pdf
There might be for example some housekeeping jobs running on the D2D right after a backup to the D2D, specially when using Deduplication, so for example the backup to the MSL should be done later.
Please check the document, which also gives you links to some tapetools to help finding the bottleneck.
There is another good document available with talks in general about backup performance and how to find bottlenecks:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460

Still keep in mind that the D2D has limitations in the overall performance, but I hope this brings you to a good improvement.

Regards,
Ralf.

andre80
Honored Contributor

Re: D2D4004 and MSL4048 copy performance

Hello Ralf

Thank you for your reply. I'll check the documents. In the meantime i've heard from hp as well that the next fw does adress some performance issues. I'll wait now and do some tests with the new fw.
If this does not help, i'll open a case. I know that the box has some limitations. but i think session copy should be faster than max 10mb/s... ;-)

do you use d2d box with dp as well? if so, do you use copy jobs over dp? if yes, what performance marks do you have?

regards
andre

Re: D2D4004 and MSL4048 copy performance

Hi André,

can you tell me if you've solved the problem with the offloadingspeed? We have an D2D4112 and a MSL8096 and I've noticed the same thing. Offloading happens in bursts of about 8MB.

Can you give us a clue?

Thanks
andre80
Honored Contributor

Re: D2D4004 and MSL4048 copy performance

Hi Maarten

Well, no we were not able to speed up the offload process. we spent several weeks with labs and testing. the problem is the housekeeping process. this process does start as soon as a virtual cartridge get unloaded after backup. then housekeeping process starts and this affects system performance. It depends on several factors how long this housekeeping does take (how much data is written on the cartridge, are other processes running ....). for example if during house-keeping other operations like backup or restore are running on the d2d box, this affects the performance of all operations on the box. this can result in the worst case that housekeeping never finishes and does take down performance for backup, or offload to tape. this is the "short" version and the main reason of slow speed.
You can probably get a bit better results if you fine tune the backup application to make sure all the jobs do for example end at the same time, another point is to size the cartridge size different...
I can't say more about it... i suggest you should log a case at support if you need more information.

regards
andré
andre80
Honored Contributor

Re: D2D4004 and MSL4048 copy performance

some additional information. have a look at the best practice paper for the d2d. you can then eventually speed up performance a bit.
well the whole thing is much more complex then to describe it in a few words... so to know more -> log a case ;-)