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Re: Getting both Tape drives working at the same time?

 
Ryan G
New Member

Getting both Tape drives working at the same time?

Hi

We have just added a second LTO4 Tape drive but we cannot get both Drives to work at the same time. Both drives work individually but they just won't run at the same time.

Server - DL360 G5

Version Netbackup 6.5.3

Tape Library - MSL2024 with two LTO4 Tape drives

Is there a setting I need to change that I'm unaware of?

Thanks

Ryan
7 REPLIES 7
thomasr
Respected Contributor

Re: Getting both Tape drives working at the same time?

Are you looking to have two different streams of data, one going to each drive, or one stream of data going to both drives at the same time?

It should be easy to get both drives active at once by creating two backup jobs -- One for C:\, one for D:\, for instance, and specifying which drive each job uses.
--
Liberty breeds responsibility; Government breeds dependence
Ryan G
New Member

Re: Getting both Tape drives working at the same time?

After our policies run at the weekend we run a manual duplication on the monday as we don't have the window to get it to tape over the weekend. So we want to set up two duplications so that we can write to two drives at the same time.
Jim Miller
Frequent Advisor

Re: Getting both Tape drives working at the same time?

Are you using disk staging storage units (DSSU)?

It the target tape storage unit setting for maximum concurrent write drives highet than 1?




Ryan G
New Member

Re: Getting both Tape drives working at the same time?

Yes we are

It is set to 2 concurrent drive which is why it's quite confusing.

They just seem to take it in turns rather than write at the same time
Jim Miller
Frequent Advisor

Re: Getting both Tape drives working at the same time?

Have you tried using the DSSU schedule rather than doing a manual relocation?
Ryan G
New Member

Re: Getting both Tape drives working at the same time?

Yeah had no luck unfortunately

Cheers

Ryan
thomasr
Respected Contributor

Re: Getting both Tape drives working at the same time?

I'm wondering if the drives are just so fast that the server can't keep up with writing two streams at once.

Have you done any testing to see how fast the data can be read from disk? If it's less than 40MB/sec (more if your data is highly compressible), then you're starving the tape drive anyway, and should consider a way to make sure each drive is fed at least (compression ratio * 30MB/sec).
--
Liberty breeds responsibility; Government breeds dependence