RE: LTO4 vs LTO3 speed

[Dan Kimmel <dkimmel@xxxxxxxxxxxxxxx>]

Dr. is probably correct here. Can the disk arms swing stuff into memory as fast as 2844 and 280D can punch memory to fibre and as fast as LTO4 can lay it on tape? What's the latency as disk controller lays a page in memory before tape controller can read it off and free it up for another disk I/O? IBMi is probably doing a pretty good job pre-fetching and utilizing multiple processors to interleave disk reads. Tape I/O is still very single threaded.

-----Original Message-----
From: DrFranken [mailto:midrange@xxxxxxxxxxxx] 
Sent: Thursday, June 13, 2013 3:26 PM
To: Midrange Systems Technical Discussion
Cc: Dan Kimmel
Subject: Re: LTO4 vs LTO3 speed

It's ALL about the I/O here.

How many disk arms are playing here?

Are said arms virtual or Physical?

If virtual what's the host partition?

Do they live on internal disk or SAN?

Mirrored or RAID or (shudder) neither?

What are the arms? (10K, 15K, SAS, SCSI, SSD?)

And also how much memory on the partition in kwestion?

         - Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 6/13/2013 4:11 PM, Dan Kimmel wrote:

> At this point we have to look to the systems guys. Larry, Jim, Pete? Could be either the 2844 or the 280D or the stuff that connects them. Could also be something completely off the box (switches, tape drive internals, ???).
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx 
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of rob@xxxxxxxxx
> Sent: Thursday, June 13, 2013 3:02 PM
> To: Midrange Systems Technical Discussion
> Subject: RE: LTO4 vs LTO3 speed
>
> WRKHDWRSC *STG
>
> Resource        Type-model  Status                Text
> CMB04            2844-001   Operational           Storage Controller
>    DC05           280D-001   Operational           Tape Controller
>    TAPGRT01       3573-040   Operational           Tape Library
>
>
> 2844 Location :   U0595.001.10782A9-CB1-C03
> 280D Location :   U0595.001.10782A9-CB1-C04
>
>
> Rob Berendt
> --
> IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 Mail to:  2505 Dekko Drive
>            Garrett, IN 46738
> Ship to:  Dock 108
>            6928N 400E
>            Kendallville, IN 46755
> http://www.dekko.com
>
>
>
>
>
> From:   Dan Kimmel <dkimmel@xxxxxxxxxxxxxxx>
> To:     Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>,
> Date:   06/13/2013 03:56 PM
> Subject:        RE: LTO4 vs LTO3 speed
> Sent by:        midrange-l-bounces@xxxxxxxxxxxx
>
>
>
> I doubt if it's CPU. At least not main CPU. There's a lot of plumbing 
> between the main CPU and I/O devices. The CPU probably loads a block 
> into memory, then passes the address to I/O controller processor which 
> copies memory to the I/O port and handles protocol. So you're 
> dependent on the speed of that I/O processor and all the channels and 
> busses that connect it to memory and to the I/O port.
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx [ 
> mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of rob@xxxxxxxxx
> Sent: Thursday, June 13, 2013 2:51 PM
> To: Midrange Systems Technical Discussion
> Subject: RE: LTO4 vs LTO3 speed
>
> Perhaps the CPU?  Perhaps a Power 6 9117-MMA P30 just ain't man enough 
> to drive this bad boy?
>
> Resource        Type-model  Status                Text
> CEC01            9117-MMA   Operational           Main Card Enclosure
> PN03             28D4       Operational           System Control Panel
> MP13             53CF       Operational           System Processor Card
> MP14             53CF       Operational           System Processor Card
> MP15             53CF       Operational           System Processor Card
> MP16             53CF       Operational           System Processor Card
> MP17             53CF       Operational           System Processor Card
> MP18             53CF       Operational           System Processor Card
> MP19             53CF       Operational           System Processor Card
> MP20             53CF       Operational           System Processor Card
> PV01             52AD       Operational           Processor Capacity Card
> SP04             294E       Operational           Service Processor Card
> SP05             294E       Operational           Service Processor Card
> ...
>
>
>
> Rob Berendt
> --
> IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 
> Mail
> to:  2505 Dekko Drive
>            Garrett, IN 46738
> Ship to:  Dock 108
>            6928N 400E
>            Kendallville, IN 46755
> http://www.dekko.com
>
>
>
>
>
> From:   Dan Kimmel <dkimmel@xxxxxxxxxxxxxxx>
> To:     Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>,
> Date:   06/13/2013 03:42 PM
> Subject:        RE: LTO4 vs LTO3 speed
> Sent by:        midrange-l-bounces@xxxxxxxxxxxx
>
>
>
> Not much difference. Leads me to believe (or suspect, anyway) your 
> performance bottleneck is not the speed of the tape, drive, or 
> connection media.
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx [ 
> mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of rob@xxxxxxxxx
> Sent: Thursday, June 13, 2013 2:23 PM
> To: midrange-l@xxxxxxxxxxxx
> Subject: LTO4 vs LTO3 speed
>
> I read a chart that says basically:
> LTO1:  Up to 40MB/s
> LTO2:  Up to 80MB/s
> LTO3:  Up to 160MB/s
> LTO4:  Up to 240MB/s
> LTO5:  Up to 360MB/s
> LTO6:  Up to 540MB/s
> http://www-304.ibm.com/services/weblectures/dlv/partnerworld/online/lt
> u29864/mod%208%20ibm%20system%20storage%20tape%20part%203.ppt
>
>
>
> And another chart that says the drive makes no difference - it's 
> totally dependent on the interface (we use 280D or 5774)  (something 
> smells rotten
>
> about this claim).
> http://www-01.ibm.com/support/docview.wss?uid=nas1b69de8ff8246ff2c8625
> 688700566393
>
>
>
> This chart says LTO4  Sustained data transfer rate*     Up to 240 Mbps
> compressed*; 120 Mbps native
> http://www-03.ibm.com/systems/storage/tape/oem/lto4/specifications.htm
> l Another chart says LTO3 Sustained data transfer rate1:  Up to 60 
> Mbps native
>
> We have the LTO4 drives in question mounted in a 3573-L4U (aka TS3200) 
> http://www-03.ibm.com/systems/storage/tape/ts3200/index.html
>
> Moved from scsi LTO3 to fiber LTO4.
>
> Full system save completed with BRMS:
>           03/06/13  06/05/13
>            LTO3      LTO4
> SAVSYS    00:07     00:07
> *IBM      00:06     00:05
> *ALLUSR   06:06     06:18
> *LINK     00:20     00:19
> Another system:
>            LTO3      LTO4
> SAVSYS    00:18     00:19
> *IBM      00:09     00:08
> *ALLUSR   02:28     02:34
> *LINK     01:30     01:23
> Granted, there was a three month time difference in between there.
> Utilization may have changed.
> System 1:
> Information collected  . . . . . . . . . :   04/11/13  04:00:02
>                                                  % of         Size in
> Description                                     Disk     1,000,000 bytes
> User libraries                                 77.11         3604127.46
> User directories                                1.50           70014.59
> Folders and documents                            .00                .14
> QSYS                                             .10            4481.52
> Other IBM libraries                              .39           18235.97
> Licensed Internal Code                           .11            5182.31
> Temporary space                                  .39           18319.04
> Unused space                                   20.41          953978.86
> System internal objects                          .16            7509.85
> Objects not in a library                         .00                .00
> TOTAL                                         100.17         4681849.74
> Information collected  . . . . . . . . . :   06/13/13  04:00:02
>                                                  % of         Size in
> Description                                     Disk     1,000,000 bytes
> User libraries                                 80.05         3741731.66
> User directories                                1.56           72747.25
> Folders and documents                            .00                .14
> QSYS                                             .10            4596.45
> Other IBM libraries                              .38           17809.87
> Licensed Internal Code                           .11            5199.08
> Temporary space                                  .31           14563.16
> Unused space                                   17.57          821259.54
> System internal objects                          .20            9196.28
> Objects not in a library                         .00                .00
> TOTAL                                         100.28         4687103.43
> System 2:
> Information collected  . . . . . . . . . :   04/11/13  04:00:04
>                                                  % of         Size in
> Description                                     Disk     1,000,000 bytes
> User libraries                                 71.73          650784.59
> User directories                                7.37           66912.19
> Folders and documents                            .00              16.75
> QSYS                                             .53            4825.70
> Other IBM libraries                             1.67           15128.99
> Licensed Internal Code                           .54            4913.39
> Temporary space                                 2.45           22214.63
> Unused space                                   14.51          131641.09
> System internal objects                          .98            8872.16
> Objects not in a library                         .00                .01
> TOTAL                                          99.78          905309.50
> Information collected  . . . . . . . . . :   05/30/13  04:00:08
>                                                  % of         Size in
> Description                                     Disk     1,000,000 bytes
> User libraries                                 70.35          638249.19
> User directories                                7.36           66821.73
> Folders and documents                            .00              16.75
> QSYS                                             .77            6973.45
> Other IBM libraries                             1.90           17223.31
> Licensed Internal Code                           .54            4913.39
> Temporary space                                 2.49           22568.05
> Unused space                                   15.78          143215.09
> System internal objects                         1.02            9224.12
> Objects not in a library                         .00                .00
> TOTAL                                         100.21          909205.08
>
>
>
> Rob Berendt
> --
> IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 
> Mail
> to:  2505 Dekko Drive
>            Garrett, IN 46738
> Ship to:  Dock 108
>            6928N 400E
>            Kendallville, IN 46755
> http://www.dekko.com
>
> --
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