[asterisk-users] Asterisk RT on Disk On Module Performance and Durability

[Tzafrir Cohen]

On Fri, Oct 06, 2006 at 05:10:34PM -0500, Erick Perez wrote:
> I understand Jeremy and Kris point of view (BTW Kris, astlinux rocks!!)
> 
> However the main question was not aswered (or i didn't get it, did I ?)
> 
> If I use a Disk on Module that has 2million hours MTBF and a Read/Write
> lifecycle of 2million times, then, How many days/weeks/months/years will
> take to do 2million read/write cycles?
> which leads to my second question.
> How do I measure/count the read and writes a normal linux system running
> asterisk does during a day, so I can extrapolate that in terms of time? Is
> there an utility?
> 
> Example: if I setup system XYZ with asterisk, then load this magical
> utility/procedure that counts how many writes the filesystem has done to /
> or to /,/tmp,/var and after 24 hours the utility/procedure says: 10thousand
> writes, then, I will do
> 10thousand writes a day multiplied by 200 days = 2 millions
> Obviously this means I will not use a RAM disk and I want to write to the
> module everytime
> 
> Then i will assume that the Disk on a Module will die after 200 days. Or am
> I completely and horribly misunderstanding the "2million
> Read/Write LifeCyle" advertised by Disk-on-Module companies?
> 
> Example:
> http://www.pqi.com.tw/product2.asp?oid=140&cate1=143&PROID=34
> ‧MTBF:2,000,000 Hours
> ‧R/W Cycle:2,000,000 Times

Hmmmm, I'm not sure that this is exactly the data you're after.

You're looking for the ammounts of writes for the disk block that gets
the most writes.

E.g: for a standard ext3 filesystem, the journal area would probably
have very frequent writes, whereas most of the system would remain
mostly unchanged.

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