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New installation of Tandberg LTO-6 + LSI Logic 9201 16e SAS card - slow performance

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Luke Arndt
New installation of Tandberg LTO-6 + LSI Logic 9201 16e SAS card - slow performance
on Mar 5, 2017 at 2:29:41 am

I just installed my first LTO-6 drive and SAS card on a Windows Server 2016 Essentials system. The drive is an external Tandberg LTO-6, and the card is an LSI Logic 9201 16e. From my interpretation of the Tandberg compatibility matrix, I think the card is supported.

I have the drivers installed for both the card and the drive, and I have also installed the HPE Library and Tape Tools that Tandberg provides on its download site.

HP L&TT is able to detect my drive, and I can run it through the various tests. All the tests pass, however I get a note saying "Drive performance is severely limited. Check HBA and cable configuration. Check that you have an appropriate HBA at http://www.hpe.com/go/connect and that drivers are correctly installed. See http://www.hpe.com/support/pat for more information."

I've tried plugging the SAS cable into a different port on the LSI card, but that doesn't seem to have changed anything.

I then formatted a tape for LTFS using the LTFS Configurator tool that Tandberg gives out. Using Windows Explorer to drag and drop a test folder onto my tape drive, my transfer speeds will top out at 170 MB/s but then will slow to almost nothing, before climbing back up to the top speed. During this time I can hear the tape drive whirring at different pitches, as if it's slowing down and speeding up as the transfer speed changes. It will do this over and over, alternating between fast speeds and super slow speeds, for the duration of the transfer.

I should point out that using HD Tune to measure my drive performance, that drive typically shows read speeds of 170 MB/s.

So it seems that something is not right. However, I'm totally new to the world of LTO and don't know what to expect so I'm not totally sure where to look. I have a hunch that the culprit would be the SAS card itself, as I've seen people recommend ATTO cards, and I've noticed they happen to be about 10 times more expensive than my LSI Logic. ☺ However, as this LSI Logic 9201 16e appears to be a recommended card by Tandberg, I thought it might do the trick.

I also tried this drive/SAS card combination in a different computer and had pretty similar results, including the warning in L&TT about the drive performance being severely limited.

With all of that info, can anybody help me out? Does it sound like I'm barking up the right tree in terms of the SAS card being the culprit? Or are there some other troubleshooting steps I can take?


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Luke Arndt
Re: New installation of Tandberg LTO-6 + LSI Logic 9201 16e SAS card - slow performance
on Mar 10, 2017 at 1:25:29 am

To update this....

After much, much, much troubleshooting, I think I have ruled out the SAS card being the culprit. Using LTFS, if I drag and drop a large file, I will get a fast, consistent transfer (100+ MB/s) all the way through.

The problem occurs when copying multiple files, but I can't detect a pattern. I copied over a dozen .mts (ranging from 100 MB to 2 GB) files from a hard drive to the tape, and the files fast with no break to stop/rewind/stop/fast-forward. If I select a few .iso files (1 to 2 GB) and copy, I get the fast rates for several seconds and then (presumably when the file has finished copying), I get the stop/rewind/stop/fast-forward cycle, and then the second file copies, the cycle repeats, and the third file copies.

This is repeatable, meaning I can copy those .mts files with no problem, yet for some reason there is a problem with the .iso files. These files are just examples too, as this type of behavior occurs when copying many different file types.

So needless to say this has me very confused!

I may end up using some third-party software, but it's frustrating to be so close to having this work well. I just can't figure out what's going on here!


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Tim Gerhard
Re: New installation of Tandberg LTO-6 + LSI Logic 9201 16e SAS card - slow performance
on May 4, 2017 at 8:34:06 pm

I've seen plenty of issues with LSI HBAs working abnormally when trying to use LTFS or tape drives in general.

I'd recommend using an ATTO H644 or H680, they work with tape drives no issues.

Tim Gerhard
Magnext
614-433-0011 x114
tgerhard@magnext.com


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Tim Jones
Re: New installation of Tandberg LTO-6 + LSI Logic 9201 16e SAS card - slow performance
on May 9, 2017 at 5:49:48 pm

To further Tim G's answer - the ATTO cards work fine with LTO-6 and earlier drives.

Tim
--
Tim Jones
CTO - TOLIS Group, Inc.
http://www.tolisgroup.com
BRU ... because it's the RESTORE that matters!


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