ADSM-L

Re: Slow LTO drives

2002-01-29 04:13:16
Subject: Re: Slow LTO drives
From: Suad Musovich <suad AT CCU1.AUCKLAND.AC DOT NZ>
Date: Tue, 29 Jan 2002 22:10:43 +1300
Have you tested it from the OS?  Large file test / small file test / mixed files

Whats your movebatchsize/movesizethresh set to in TSM?

The LTO drives work well with bigger files and start to suffer on small ones.

I get only aggregate 5-10 GB/hr when I migrate a stgpool with small
fileservers/workstations but get 25-35 GB/hr for db servers. I've actually got
some I/O problems myself that are begin fixed by plugging in some extra 
bandwidth,
so I can tell you the difference after that.

Suad
--
On Tue, Jan 29, 2002 at 12:23:56AM +0300, Bill Smoldt wrote:
On Tue, Jan 29, 2002 at 12:23:56AM +0300, Bill Smoldt wrote:
> I've gone back through the list about the slow LTO issues.  I haven't found
> anything that works in this case.
>
> TSM V4.2.1.9
> W2K SP2
> 3584 Library at latest firmware
> LTO drives at 18N2 firmware latest on devdrvr
> Netfinity xSeries 350
> LTO Device driver is 4.0.2.4 - tried 4.0.2.1 and previous versions of
> 4.0.1.x
> RSM disabled.
>
> Possible issues:
>
> Drives and library are connected using the motherboard SCSI 7899 Ultra 160
> chips - one per channel - no internal devices connected.  I know about the
> Microsoft vs Adaptec supplied driver but can't determine if it applies to
> this chipset.
>
> Cable length to get to the library is long but already installed under the
> floor - at least the 12 meter limit and maybe a bit longer (I'm trying to
> find out)
>
> These drives write at about 4G/hour even on 4 GB files.  The device drivers
> don't stay loaded after a reboot but have to be updated by hand.
>
> Does anyone have any suggestions to speed these drives up?
>
> Thanks,
>
> Bill Smoldt
> STORServer, Inc.
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