On Fri, Dec 4, 2009 at 1:06 AM, Erik Trimble <erik.trim...@sun.com> wrote:
> Hey folks.
>
> I've looked around quite a bit, and I can't find something like this:
>
> I have a bunch of older systems which use Ultra320 SCA hot-swap connectors
> for their internal drives. (e.g. v20z and similar)
>
> I'd love to be able to use modern flash SSDs with these systems, but I have
> yet to find someone who makes anything that would fit the bill.
>
> I need either:
>
> (a) a SSD with an Ultra160/320 parallel interface (I can always find an
> interface adapter, so I'm not particular about whether it's a 68-pin or SCA)
>
> (b) a SAS or SATA to UltraSCSI adapter (preferably with a SCA interface)
>
>
Hi Erik,
One of the less well known facts about SCSI is that all SCSI commands are
sent in legacy 8-bit mode. And it takes multiple SCSI commands to make a
SCSI drive do something useful! Translation - it's s-l-o-w. Since one of
the big upsides of an SSD is I/O Ops/Sec - get ready for a disappointment if
you use SCSI based connection. Sure - after the drive has received the
necessary commands it can move data blocks reasonably quickly - but the
limit, in terms of an SSD will *definitely* be the rate at which commands
can be received by the drive. This (8-bit command) design decision was
responsible for SCSIs' long lasting upward compatibility - but it also
turned into its achilles heel; that ultimately doomed SCSI to extinction.
I understand exactly the problem you're solving - and you're not alone (got
4 V20Zs in a CoLo in Menlo Park CA that I maintain for Genunix.Org and I
visit them less than once a year at great expense - both in terms of time
and dollars)! IMHO any kind of a hardware "hack job" and a couple of 1.8"
or 2.5" SATA SSDs, combined with an OpenSolaris plugin SATA controller,
would be a better solution. But I don't like this solution any more than I'm
sure you do!
Please contact me offlist if you have any ideas and please let us know (on
the list) how this works out for you.
Regards,
--
Al Hopper Logical Approach Inc,Plano,TX a...@logical-approach.com
Voice: 972.379.2133 Timezone: US CDT
OpenSolaris Governing Board (OGB) Member - Apr 2005 to Mar 2007
http://www.opensolaris.org/os/community/ogb/ogb_2005-2007/
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