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2 drives on Library MSL4048 LTO4 can not run backup simultaneously

 
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Occasional Advisor

2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Dear Experts,

My company has bought a Tape Library MSL4048 with 2 drives. This tape library was installed to a HP Proliant Backup server via SAN Switch. So there are a Zone between Tape Library and backup Server.

On the backup server, I have installed Library driver, so I can see the Library status with both tapes in Device Manager.

I run testing backup using HP Data Protector v.6.11 Software.
I can run backup testing using both tape drives one by one. I mean that firstly, I run backup with drive 1 and after the backup process finished, I run backup testing again using drive 2. Both backup process can run successfully.

I got problem while trying to run backup using both drives simultaneously (load balance).
Even though I have set using 2 tape drives, while backup running, it always use drive 1 to backup meanwhile drive 2 always in "Inactive/waiting" status.
Even though I tried to backup big data (about 900GB), it never use drive 2 (balancing).

I have tried this with 2 the other software backup, like NetVault and CommVault. But, I still got same problem (can not use 2 drive simultaneously for running backup)

I have talked to HP Engineer, but they always said there is no hardware problem in library system. We have replaced tape drive 2 with another and change drive 2 position to drive 1 position, but the problem still same.

I just confused, what happen in my new tape library? Kindly need for any suggestion, please

Thank you

regards,

--Feri--

16 REPLIES 16
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Valued Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

hello Feri,

in Data Protector, do you have lincense for 2 drives?

andras
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Honored Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Feri,

are you aware that a single Filesystem (e.g. serverA c:) will always go to a single drive only? on this drive you can multiplex several FS e.g. (serverA C:, serverA D:, and ServerB F;) depending on your settings.

only if you set concurrency for a tape drive to 1 and backup at least 2 filesystems your second drive will actually be used.

Regards,
Bernhard
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Trusted Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

previous posts are clear enough,

first point you should check is the 2nd drive license,

if it is OK then try to force the library by creating two different backup instances starting on the same time or say 15 minutes delay and try to backup one to Drive 1 and other to drive 2, if this works then you are in the one filesystem to one drive point,

what is the host OS you are backing up?

May be you can create two different backup sets as mentioned above and share the directories to those two backups and two drives if you have only one disk to be backed up.

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Occasional Advisor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Dear All,

I got confirmation from HP Data Protector Software team that my software is valid to support 2 tape drives.

For backup testing, I have tried to make 2 backup specifications where each backup specification is pointed to each tape drive.
For Example : backup specification 1 (bkp01) is pointed to Tape Drive 1 and backup specification 2 (bkp02) is pointed to Tape Drive 2.
bkp01 is set to backup drive "C" (14 GB) and bkp02 is set to backup drive "F" (105 GB) from another External Disk drive.

Then , I run both backup specifications at the same time. The result, both backup specification can run at the same time.

But, the problem is I want to run 1 backup specification once and use both tape drives simultaneously to backup. At the backup process , data will be separated written into 2 tape media through each Tape Drives.

If I did this, backup process always use drive 1 in backup process, meanwhile Drive 2 always INACTIVE/Waiting.

Is this problem caused by HP Data Protector ability limitation to use 2 tape drive simultaneously? or caused by hardware problem?

Please help, me...please

Thanks,

--feri-
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Trusted Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

That is the point I am trying to clarify,

all backup softwares -afaik- works same.

It is the basic operation of Input/Output. If you have only one input, this brings you to a single output. If you are able to give more than one input to the backup software in that case you can use more than one output (tape drive in your case).

You should seperate your files to be backed up into two pieces and distribute them to two drives, in a single or double backup configuration.

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Occasional Advisor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Dear ILLIMAN,

Sorry, I am still newbie in this backup system.
You said that if I want to make both drives working simultaneously (parallel) , I must separate the input into 2 and than I will got the 2 output also, doesn`t it?

I have already tried to backup 2 different drives (drive C and drive F which I have told before), but I set them into one backup specification, and then run the backup.

I also got that the backup system always use Drive 1 to backup, but drive 2 status is still INACTIVE.

Actually, do you know what settings that I should do so I can run backup using both drive running parallel?

Can This Tape Library MSL4048 with 2 drives support this requirement?

Please suggest

Thanks,

--feri--
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Trusted Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

I don't know the exact setting but there must be a setting in DP for the instances that can write parallel to a single output and its default value must be 4,

This setting means if you have 4 inputs you can write them to a single drive,

You can set this parameter to 1 to see the difference, but as I said I can't remember the exact name of the parameter.
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Trusted Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Bernhard in the previous posts mentioned bout that setting:

only if you set concurrency for a tape drive to 1 and backup at least 2 filesystems your second drive will actually be used.

Concurrency is the parameter I was talking about.
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Honored Contributor

Re: 2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Hi
This looks purely a SW configuration issue as the MSL 4048 do not have any limitation on this

I can tell you how to check if the HW can support two parallel stream of data on two different tape drives in the MSL4048

stop yout backup application services
install LTT on your sistem
start LTT and select firt drive and then one the tests, or the "device perf test"

then start again a second instance of LTT, it will ask you to specify a new directory where to save the logs, then select the second drive and run again one of the tests.

At thay point you will be able to confirm the HW is working fine