Veritas-bu

[Veritas-bu] LTO3 show shining

2006-09-26 10:15:30
Subject: [Veritas-bu] LTO3 show shining
From: jpiszcz at lucidpixels.com (Justin Piszcz)
Date: Tue, 26 Sep 2006 10:15:30 -0400 (EDT)
Very interesting + useful information, thanks!

On Tue, 26 Sep 2006, Joe Royer wrote:

> 27MB/s is for HP drives, and HP employs the best overall data rate
> matching mechanism.
> 40MB/s for IBM drives, and it's not variable like HP.  The drive must
> literally switch gears resulting in speeds of 40, 50, 60, 70 or 80 MB/s
> 7.5MB/s for Seagate/Quantum/Certance but don't be decieved by their
> "13-speed" marketing.  The drive not only needs to switch gears, but it
> can only switch at the beginning or end of the tape, making shoeshining
> a very real possibility.
>
> Again, I don't have references, so take me with a grain of salt ;)
>
>
> ----Originial message----
> Date: Mon, 25 Sep 2006 18:17:34 -0600
> From: "Scott Jacobson" <SJACOBSO at novell.com>
> Subject: Re: [Veritas-bu] LTO3 show shining
>
> Remember, variable speed matching supported on some manufactures tape
> drives doesn't necessarily make Justin's suggested performance speeds an
> absolute.  But his performance number's are a good base line.
> -sj
>
>>>> Justin Piszcz <jpiszcz at lucidpixels.com> 9/25/2006 3:20 PM >>>
> If your speeds are < 27MB/s, you get "Shoe Shining" - 27MB/s is the
> minimum you are supposed to run an LTO3 drive at.
>
> Justin.
>
> On Mon, 25 Sep 2006, Hindle, Greg wrote:
>
>> Nb 5.0 mp6 Solaris 9
>>
>> Ok Maybe this has been said before but with all the talked about show
>> shining LTO3 FC drives. Currently I have NDMP backups going to my LTO 3
>> drives. Early next year when we buy more LTO3 drives we are changing
>> over our non-ndmp backups to go to LTO3 drives as well.  My questions
>> are this:
>>
>> What settings need to be changed and to what to minimize LTO3 show
>> shining?
>>
>> How can I tell if my drives are show shining? Where do I look, what
>> commands do I need to run etc.?
>
>
> -- 
> Joe Royer / SysAdmin / Digital Motorworks / 512-692-1028
>
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