Fantasy time - Solid state disks.

[Paula J Frazer-Campbell]

Hi

It is Friday and I had a little time spare so I am looking at Solid state disks. "One Can Dream".

Does anyone have any experiance of these on a HP system.

Setting up?
Failure rates?
LVM and these disks?
Actual performance on a busy database?
Mirrordisk?

Thanks in advance.

Paula

[Dave La Mar]

By "solid state disks", are you referring to something along the line of an XP256/512?
We are using the XP512 and, yes,
I would have some input.
NA my reply if not.
dl

[Paula J Frazer-Campbell]

Dave
Not sure on the xp256.

Solid state = no moving parts - basically memory the behaves like a disk.

Paula

[Paula J Frazer-Campbell]

Hi Dave
Just looked up xp256 - sorry but no.

Paula

[S.K. Chan]

We are in the middle of evaluation this product for Oracle transaction purposes.

http://www.imperialtech.com/products_megaram5k.htm

It'll be interesting to see how turns out. Another product which is "suppose" to be good is the Quantum Snap Server. I would imagine not needing the mirroring since those are on RAID, failure rate .. surely by 10 fold.. well all will be known soon if we decide to purchase it.

[Paula J Frazer-Campbell]

Dave

Check out:-

http://www.bitmicro.com/



Paula

[Robert Gamble]

Cool !!

Paula, so is this basically a RAM type of device ... that is accessed by /dev/dsk/x ?

[Patrick Wallek]

Very interesting stuff Paula.

I would think that if the devices are still seen as regular disk devices, /dev/dsk/c?t?d?, which it sounds like they should be, that LVM setup, mirroring setup, etc. would be the same as what we are used to now.

I can see where those would definitely be much faster. Theoretically, your limiting factor now would probably be your scsi or fibre links since you're not going to have the latency associated with head movement on the disk.

That stuff sounds great. I can definitely see where future storage $$$$'s (or Euros or Pounds Sterling.....) will be spent.

It would be great to be able to get an evaluation unit with about 200GB of storage. That would be lots of fun.

[Steve Miller_4 · Accepted solution]

I've had great experiences with SSD using two different vendors. The first was Solid Data Systems (OEMd by MTI). *Very* expensive at the time - about $25k/GB. The second, and one I'd recommend, was Platypus. Much cheaper at about $2500/GB (list) and very scalable.

http://www.platypus.net

Both were used in an Oracle Applications environment for the TEMP tablespace datafiles, which are very write intensive and the EMC write cache could not keep up. Huge performance boost for OLTP and batch processes (ranged from 200-1000% for large batch jobs).

- Dual attached Fibre Channel for LVM alt link,
- Shows up as 2 /dev/dsk/cXtYdZ drives
- Does internal hardware mirroring (stay away from mirror-ux as it will add overhead)
- Internal hard drive for writing data out in the event of long term power failure (and it works)
- Battery backup...

I never had a failure in my experience (about 2 years), but I'm sure there are some out there. Just a matter of how the device handles it and whether it requires downtime.

One word of caution - there's not (at least at the time) any way to 'sync' two of these devices over long distances for disaster recovery purposes. Even if there was, timing the EMC SRDF process and SSD sync process would be a challenge. If that's not a concern, then go for it (if you can get your boss to give you the $$$)

[Mark Grossman]

We have two Raid systems from Seek Systems out of Bothell WA. The disks are normal 36 or 73gb, but the Raid system has Solid State Disk for caching. They have an SSD accelerator product that hooks to your existing disks externally or the full Raid system with SSD cache, hot spares, etc. To get all disks SSD would be way too expensive for us.
LVM and system setup is normal for these products.
It definetly helps online performance for Oracle.

Mark

[A. Clay Stephenson]

Hi Paula:

I haven't used these guys on HP-UX but I have used them on other UNIX boxes and they can easily give 25x increases in throughput. Believe it or not, my first use of one was in the early '80's on an Apple II running the UCSD p-system. That one was a whopping 304KB; the one performance number I remember was that complex Pascal compiles went from about 300 lines/minute to about 3000 lines/minute.

I tended to restrict their use to temp files or as essentially very large arrays for analysis programs that were too big to fit into memory. I have also used them as database temp tables after loading them from the actual table. Even with the newer internal disk backup, battery-backed RAM models, I've never been comfortable using them as actual database or critical data storage. They are ideal in database cases where you are doing read-only queries; there you will easily see 25x speed increases.

Unless you are mirroring to another solid-state disk, mirroring is not really practical because you would then have the same disk bottleneck.

Regards, Clay

[Bill McNAMARA_1]

Hi Paula,

there are Solid State Disk modules for the SC10 disk subsystem. (I saw these around a year and a half ago - they're probably more now ie FC60 etc..)

They are REAL expensive though... for the likes of the amazon.com and heavy hit webserrvers.

Later,
Bill

[Bill McNAMARA_1]

Here's the link:

http://www.hp.com/products1/storage/products/disk_arrays/disksystems/sc10/infolibrary/index.html

[Wodisch]

Hello Princess,

aren't those supposed to turn up now, for Intel (and others) have announces huge FLASH-RAM chips?

Just my $0.02,
Wodisch
PS: Clay - I still have my old Apple II with 1MB of "RAMdisk" (good things never die :-) running UCSD with diskdrivers of my own (for speed)

[David Diaz]

Hi,
We have solid state disks from Solid Data Systems (http://www.soliddata.com) on V, T, N and K class 9000/800 servers. We run Sybase 11.9.2 on them. Our database on the V is pretty busy (Over 550 users connected at once, lots of I/O). The other boxes are for reporting, development, etc... We strictly use the "RamDisks" for tempdb though.
Setup and install is easy, like installing an external hard drive.
You can use SAM to create VG's and LV's, no problem.
Here's the best part, failure rate for us has been NIL in the three years I've been here, performance has improved tremendously as well.
Overall, it's been a very good investment (that's how your boss has to see it ;>] ).

Hope this helps,

David

[George_Dodds]

Hey Paula,

Maybe if we ask very very nicely we could get one to evaluate!

Or maybe not!

Shame, got space in the garage!

Cheers

George

[Dave Wherry]

Paula,
Here's some information on that Solid Data Systems device that David Diaz mentioned.
HP resells it as the Solid State Disk Excellerator. It comes in SCSI and Fibre channel versions. Baiscally you start with a frame and add memory array boards. The low end config. is 512MB and scales up to 32GB. You add 512MB, 1GB or 2GB boards.
Access time is quoted as 14 or 50 microseconds.
Tranfer rates are:
40MB/sec for SCSI and 100MB/sec for FC burst.
40 MB/sec for both, sustained.

List prices for the frame are:
$22,000 to $32590 for SCSI and
$26,538 to $41,806 for FC.
The boards are:
$6,474 for 512MB
$12,864 for 1GB
$25,728 for 2GB
And of course some different bells and whistles and configurations.

Like Clay, back in the old days I saw a solid state device for Prime systems. I think it was about 20MB or so. Very expensive, but very fast. The site I knew that had one loved it.

[John Bolene]

An aside, on our UNISYS mainframe we use 2 Zitel SSD disk subsystems of 1G each and the main I/O time is the data transfer time.

These are used for the hotspot files which are defined as being less than 10 Meg in size and having total I/O's of more than 2% of total I/O.

Normally we get about 25% of the total I/O's from these devices.

[Paula J Frazer-Campbell]

Hi Guys

Thanks for all the answers.

Once again the Forum comes through.

I now have more than enough info


Notice the capitol "F" on Forum as this place deserves it.


;^)

Paula