CentOS - Jan 2010 - CentOS Digest, Vol 60, Issue 13

Another issue to consider with SSDs is that they are based on Flash technology.
Each flash cell can only be written on about 10,000 to 100,000 times or so (*),
so if you're using extensive read/write on your server you will be impacted.
SSD manufacturers go around this issue by giving some intelligence to the drive
controllers, so that they minimize the per-cell usage (which means moving things
around a bit internally, transparently to you), so in many cases you will not
see any impact. However, I would be careful on what I run on it, and what
services are enabled, maybe having another disk around for write intensive apps.

Emanuel

(*) http://en.wikipedia.org/wiki/Solid-state_drive#Disadvantages

----
Emanuel Machado, PhD.
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Sent: Wednesday, January 13, 2010 12:00 PM
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Subject: CentOS Digest, Vol 60, Issue 13

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Emanuel Machado wrote:
> Another issue to consider with SSDs is that they are based on Flash
> technology. Each flash cell can only be written on about 10,000 to
> 100,000 times or so (*), so if you're using extensive read/write on
> your server you will be impacted. SSD manufacturers go around this
> issue by giving some intelligence to the drive controllers, so that
> they minimize the per-cell usage (which means moving things around a
> bit internally, transparently to you), so in many cases you will not
> see any impact. However, I would be careful on what I run on it, and
> what services are enabled, maybe having another disk around for write
> intensive apps.
No, you can write (append) as often as you like. It is the erase cycles 
that are limited. So the chip life depends on how often those files get 
deleted.

Bob McConnell
N2SPP