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2 drives on Library MSL4048 LTO4 can not run backup simultaneously

Feri_1
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
Andras Ordogh
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
Bernhard Mueller
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
Bulent ILIMAN
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.

Feri_1
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-
Bulent ILIMAN
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.

Feri_1
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--
Bulent ILIMAN
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.
Bulent ILIMAN
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.
Marino Meloni_1
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

Feri_1
Occasional Advisor

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

Dear Maroni,

Sorry, did you mean that I have run test per drive (one by one)?
Yes, there is no problem if I run test backup using per drive (one by one). But, the problem comes while trying to run both drive simultaneously with one Backup specification.

I have tried to check concurrency and has set it to the requirement. But I still can not use both drive simultaneously to run one backup specification.

I have called HP Data Protector Engineer to run backup, but He gave up. The hardware support also.

Oh ya...for compare testing, today I am testing to run same backup specification and trying to run it on both drives using Quantum scalar i40.
It works. I can run one backup specification and use both drive simultaneously. ;(

Oh..I am stuck....is there any suggestion, please?

Thanks,
Marino Meloni_1
Honored Contributor

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

Hi Feri

what I mean is to run two LTT instance in the same time, one directed to one drive and one directed to the second drive.
The new versions on LTT support multiinstances that allow to test using stream to multiple drives
Marino Meloni_1
Honored Contributor

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

Would be good also if you can collect a support ticket from LTT and attach it here so I can have an overview of the HW
Thanks
Bernhard Mueller
Honored Contributor

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

Feri,

you need to check *two* concurrency settings.

there is one default value for each drive
devices - select the drive, props, advanced, concurrency (default with tapes is 4)

then there is one for the backup device *in the backup specification*
backup - select your spec, destination, the drive, props for *this* drive in *this* backup spec, concurrency (default would be 4 as well)

check this for both drives in you backup spec and it *should* override any default setting you made under the devices and media section... if not change it there too.

if concurrency in all instances is set to 1 it should definitely backup *one* backup object (filesystem, e.g. C:) on *one* drive and the *second* backup object (e.g. F:) on the *second* drive (assuming you have two tapes available from the respective pool...

There is *no* way to split the backup of *one* object onto two different drives. this is typically of no use since the LTOs used nowadays are usually much faster than a single filesystem will deliver the backup data.

Regards,
Bernhard
agent-orange
Occasional Advisor

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

Hi

I have the same problem here. We have 3 MSL6060 with each 2 LTO3 drives and I also can not use 2 drive simultaneously for running backup. The strange thing is, this worked some months ago and now not anymore. Licence problem is it definitely not.

The currency for each drive is set to 1 and load balancing is min: 1 & max: 1

When I start a backup job, which 2 drives are set, drive 1 is writing drive 2 "Inactive/waiting"

It's a Job with about 7 Server, only file-system.

Feri_1
Occasional Advisor

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

Dear All,

Thank you for any suggestion.

HP Enginner just did Firmware update for Tape Library..Now, All drive run normally..

thank you
Michael A. McKenney
Respected Contributor

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

using Symantec Backup Exec, I can run three tape drives at the same time. This is on an Adaptec controller with SCSI disconnect enabled. I could not accomplish this on an HP tape drive with HP controllers because I can't enable SCSI disconnect. You would need separate controllers for each tape drive to run them at the same time. If they are on the same controller, the two tape drives would time out because HP neuters the controller functionality. It is like them making their SCSI controllers internal or external only instead of both by disabling the on-board termination and using cable termination.