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From Terje Marthinussen <tmarthinus...@gmail.com>
Subject Re: Use of SSD for commitlog
Date Wed, 08 Aug 2012 16:20:54 GMT
Probably you can get an intel 320 160GB or a Samsung 830 for the same price as the 146GB 15k
rpm drive.

Overprovision the SSD 20% and off you go.

It will beat the HDD both sequentially and randomly.

Terje

On Aug 8, 2012, at 11:41 PM, Amit Kumar <kumaramit.extra@gmail.com> wrote:

> 
> There is a really good presentation about SSD and Cassandra on youtube by Rick Branson.
I highly recommend watching it.
> 
> http://www.youtube.com/watch?v=zQdDi9pdf3I
> 
> 
> Amit
> On Aug 8, 2012, at 6:23 AM, Hiller, Dean wrote:
> 
>> A 7.5 is probably fine and can still beat it as it is going to be the speed of writing
not seeking(and I am not sure if they spec hard drives with a write time when not seeking….not
sure).  Remember that drives are rated on how fast they spin…this disk should not be spinning
a lot(in theory)…it is always writing.
>> 
>> Even on a read, it would do one seek and then do a very long sequential read(and
I think that only happens on startup anyways).
>> 
>> Later,
>> Dean
>> 
>> From: Darvin Denmian <darvin.denmian@gmail.com<mailto:darvin.denmian@gmail.com>>
>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
>> Date: Wednesday, August 8, 2012 7:16 AM
>> To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
>> Subject: Re: Use of SSD for commitlog
>> 
>> Thanks for your reply Dean,
>> 
>> considering your reply.... maybe I use a 15k RPM SCSI Disk, I think it'll perform
better than a SSD disk.
>> 
>> On Wed, Aug 8, 2012 at 10:01 AM, Hiller, Dean <Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov>>
wrote:
>> Probably not since it is sequential writes….(ie. Seek performance is the big hit
and if it is sequential it should not be seeking and is about just as fast as an SSD in theory).
 In practice, I have not measure the performance of one vs. the other though…that I always
the best way to go.(you could write a micro benchmark test with warmup writes and then stream
writes to and see how it does without cassandra).
>> 
>> Dean
>> 
>> From: Darvin Denmian <darvin.denmian@gmail.com<mailto:darvin.denmian@gmail.com><mailto:darvin.denmian@gmail.com<mailto:darvin.denmian@gmail.com>>>
>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>"
<user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>>
>> Date: Tuesday, August 7, 2012 8:34 PM
>> To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>"
<user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>>
>> Subject: Use of SSD for commitlog
>> 
>> Hi,
>> 
>> Can somebody tell me if is there some benefit in use SSD Disks
>> for commitlog?
>> 
>> THanks!
>> 
> 


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