Slow LTO-8 performance

[Dewhattens]

I am copying LTO-8 to LTO-8 using the ltfscopy program.  This is taking well over 35 hours and for a tape of 10.6 TB I believe this should be around 10 hours at 300MB/sec.

The size of files is about 3 GB but varies.  Anybody got any useful information here.

cd "C:\Program Files\HPE\LTFS\"
mkdir L:\LB0004
.\ltfscopy -c -s M:LA0004\ -d L:LB0004 --recursive --verbose

From the flashing lights on the drive its obvious that it is not streaming.   It reads from one drive then the lights stop flashing and then start flashing on the other drive.   So that would give me 2x10 hours as a minimum but not 35!!

[NarayanKK-SO]

@Dewhattens

The tape to tape copy performance depends on the so many factors like, the tape health, connection between the 2 devices (If 2 drives are used) & the type of data. Did we try doing a copy of smaller chunk of data to check if this is really an issue with the HW or the associated SW ? Hope this test will help us understand the situation. 

Hope this answers the query. Do let us know if you any more question.

Thanks,

[Dewhattens]

Well this has been a project trying to get 800TB from an Isolon to LTO-8 tapes.    The files are zipped and the size can vary. 

Maybe after the project has finished I can try with specific different sizes to try and provoke more streaming.  At present what I can see is that the data comes from the source, gets put in some windows cache using FUSE and then to the target. I am getting FUSE is the problem since its only a FUSE emulation and not the true FUSE Open source.

At various times I also see in the windows log that I get LTFS errors which comes from the FUSE driver.

All in all there are too many problems and without a support contract I cannot get much further. 

My next test will probably be to run it on Ubuntu to see if its windows and the FUSE emulation which is the problem.

[Dewhattens]

@NarayanKK-SO 

Another problem I have noticed which has happened several times.

The lftscopy program can be running for several hours and then it all seems to stop for many hours (for example over the weekend).   I hit carriage return once and then it all carries on again. Its like it is  waiting for some input but there is nothing printed on the screen.   Looks like some old break point which has not been removed ???!!!!

[NarayanKK-SO]

@Dewhattens

Trying a diff OS platform could tell us if there are any compatibility or limiations. The session restarting could be something to do with timeout settings. If there are any retry options and timeout values. We can change them and test.

Do let us know the outcome of the tests.

Thanks