Henrik,
That's very interesting, and it looks like you're getting pretty good
throughput overall. I wonder though, about tape 360024 on the Windows
machine... it got much better throughput than any of the others on either
machine. Do you think that was because of better compression on that
volume?
Regards,
Robin Sharpe
Berlex Labs
Henrik Wahlstedt
<SHWL AT STATOIL DOT COM
> To
Sent by: "ADSM: ADSM-L AT VM.MARIST DOT EDU
Dist Stor cc
Manager"
<[email protected] Subject
.EDU> Re: Performance with move data and
LTO3
01/09/2007 10:26
AM
Please respond to
"ADSM: Dist Stor
Manager"
<[email protected]
.EDU>
Hello,
A late answer about LTO3 performance, but for the records. Origal post is
below.
I used 'audit vol volume_name skippartial=y fix=n' and 'move data
volume_name reconstr=no'.
Since the tape drives are not connected to a switch I used the information
and timing from actlog when the tape is opened as an input volume and when
the processing is done. Maybe not the best way but it will give me a clue
about the performance.
With IBM drives on Windows:
select volume_name, est_capacity_mb, pct_utilized, pct_reclaim from volumes
where volume_name='360023'
VOLUME_NAME EST_CAPACITY_MB PCT_UTILIZED
PCT_RECLAIM
------------------ -------------------- ------------
-----------
360023 762938.0 34.2
0.0
select volume_name, est_capacity_mb, pct_utilized, pct_reclaim from volumes
where volume_name='360024'
VOLUME_NAME EST_CAPACITY_MB PCT_UTILIZED
PCT_RECLAIM
------------------ -------------------- ------------
-----------
360024 762938.0 49.6
0.0
select volume_name, est_capacity_mb, pct_utilized, pct_reclaim from volumes
where volume_name='360125'
VOLUME_NAME EST_CAPACITY_MB PCT_UTILIZED
PCT_RECLAIM
------------------ -------------------- ------------
-----------
360125 762938.0 45.6
0.0
360023
Audit: 196306 items / 33m04sec
Move data: 196306 items / 273,902,675,481 bytes / 65m22sec ~69,84Mb/s
360024
Audit: 93202 items / 41m57sec
Move data: 93202 items / 397,207,010,912 bytes / 53m29sec ~123,8Mb/s
360125
Audit: 21470 items / 71m02sec
Move data: 21470 items / 369,229,158,737 bytes / 104m28sec ~58,9Mb/s
With HP drives on Linux:
select volume_name, est_capacity_mb, pct_utilized, pct_reclaim from volumes
where volume_name='350075'
VOLUME_NAME EST_CAPACITY_MB PCT_UTILIZED
PCT_RECLAIM
------------------ -------------------- ------------
-----------
350075 409600.0 41.6
0.0
select volume_name, est_capacity_mb, pct_utilized, pct_reclaim from volumes
where volume_name='350204'
VOLUME_NAME EST_CAPACITY_MB PCT_UTILIZED
PCT_RECLAIM
------------------ -------------------- ------------
-----------
350204 441710.3 68.9
31.1
select volume_name, est_capacity_mb, pct_utilized, pct_reclaim from volumes
where volume_name='350257'
VOLUME_NAME EST_CAPACITY_MB PCT_UTILIZED
PCT_RECLAIM
------------------ -------------------- ------------
-----------
350257 463674.8 49.5
50.6
350075
Audit: 705210 items / 38m30sec
Move Data: 705210 items / 179,065,879,072 bytes / 36m48sec ~81,1Mb/s
350204
Audit: 36603 items / 71m35sec
Move Data: 36603 items / 319,319,489,218 bytes / 75m11sec ~70,79mb/s
350257
Audit: 95345 items / 54m06sec
Move Data: 95345 items / 240,739,702,948 bytes / 46m26sec ~86,4Mb/s
I guess Wanda is right about the buffer usage on Windows when performing a
Move data. Audit seems OK. One thing is
for sure, as always, backup stgpool will be disk to tape...
On the other end I´m curious about the Linux system that performs Move data
faster than Audit. And have less variance in speed than the Windowsbox.
However my main interest was performance of LTO drives and (HP vs IBM
drives). I guess our Linux box will
outperform the Windows box with adequate hardware.
//Henrik
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Salak Juraj
Sent: den 22 december 2006 11:44
To: ADSM-L AT VM.MARIST DOT EDU
Subject: AW: Performance with move data and LTO3
Hi!
I saw some related information (source:Quantum) under
http://www.datastor.co.nz/Datastor/Promotions.nsf/4a91ca5e06d20e15cc256ebe0002290e/d954d1c5e5e6df09cc25723b00740956/$FILE/When%20to%20Choose%20LTO3%20Tape%20Drives.pdf
best
Juraj
> -----Ursprüngliche Nachricht-----
> Von: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] Im Auftrag
> von Henrik Wahlstedt
> Gesendet: Donnerstag, 21. Dezember 2006 15:43
> An: ADSM-L AT VM.MARIST DOT EDU
> Betreff: Re: Performance with move data and LTO3
>
> Nice one! I get back on this after the Holidays.
>
> Thanks
> Henrik
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf
> Of Prather, Wanda
> Sent: den 19 december 2006 18:15
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Performance with move data and LTO3
>
> Interesting.
>
> Differences in IBM vs. HP LTO3 drives:
>
> I have been told that the IBM drives do "smart"
> compression using a bypass buffer. If a block of data is going to
> expand during compression, the IBM drives will stop compression and
> write the uncompressed block, which should make them a bit faster.
>
> Re tape to tape operations:
>
> I have observed the same behavior; tape to tape operations are
> inexplicably slower than you would expect when the TSM server is on
> WINDOWS. I have observed this with fibre drives, and SCSI drives,
> 3590 and LTO. I suspect it has something to do with buffer use, but
> since Windows provides no tools whatever to measure performance of
> tape devices or buses with tapes on them, I've never been able to make
> any other determination.
>
> I don't think it is a READ issue with the drives. Try testing using
> an AUDIT; that just reads the tape and doesn't write anything. I
> suspect you'll get faster READ times. I would be interested in seeing
> your results!
>
>
>
> Wanda Prather
> "I/O, I/O, It's all about I/O" -(me)
>
>
>
>
> -----Original Message-----
> From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf
> Of Henrik Wahlstedt
> Sent: Thursday, December 14, 2006 10:37 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Performance with move data and LTO3
>
> Hi,
>
> I wonder what transfer rates (move data from drive to drive) I am
> supposed to see with LTO3.
>
> I have two TSM servers, one 32-bit Win2k3 and one 64-bit
> 2.6.9-11.Elsmp, with a SL500 and FC LTO3 drives.
> Similar HW (HP DL585) except for one server have HP- and the other
> have IBM drives. Drives are on separate PCI busses.
>
> I used a dataset of 50Gb with large files, same file type on both
> systems. Only scratch tapes and no expiration on the datasets.
> No other tape activity on the systems during the tests.
>
> I tested disk->mt0->mt1->mt2->mt3->mt1->mt0->disk
> From disk to tape I get a throughput of 74-76Mb/s with IBM drives,
> (migration).
> From tape to tape, (move data), with HP drives I get a throughput of
> 30-46Mb/s and with IBM drives I get 39-59Mb/s.
> From disk to tape, (move data), with IBM drives I get a throughput of
> 44Mb/s.
>
> Apperently write speed seems OK but read spead is an issue?!
> Or is this normal?
>
>
>
> Thanks
> Henrik
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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