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From Mohit Anchlia <mohitanch...@gmail.com>
Subject Re: Commit log on USB flash disk?
Date Sat, 16 Nov 2013 19:14:13 GMT
In our testing USB tends to be slower. If there is something more integrated internally would
give you better performance

Sent from my iPhone

On Nov 16, 2013, at 8:30 AM, Dan Simpson <dan.simpson@gmail.com> wrote:

> It doesn't seem like a great idea.  The USB drives typically use dynamic wear leveling.
 See this analysis on wear: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CD8QFjAC&url=http%3A%2F%2Fwww.usenix.org%2Fevent%2Ffast10%2Ftech%2Ffull_papers%2Fboboila.pdf&ei=qZyHUrizFtKAygGs9YGoCg&usg=AFQjCNHTC7d6fcI1CNWmjbHMwgXI1nUWcQ&sig2=BaWgHj3ib-cQOBPQsoCadA&bvm=bv.56643336,d.aWc&cad=rjt
> 
> If you you do end up using it, make sure to monitor write latency so you don't get hit
by the bus.
> 
> 
> On Sat, Nov 16, 2013 at 6:12 AM, David Tinker <david.tinker@gmail.com> wrote:
>> Our hosting provider has a cost effective server with 2 x 4TB disks
>> with a 16G (or 64G) USB thumb drive option. Would it make sense to put
>> the Cassandra commit log on the USB thumb disk and use RAID0 to use
>> both 4TB disks for data (and Ubuntu 12.04)?
>> 
>> Anyone know how long USB flash disks last when use for a write heavy
>> workload like this?
>> 
>> Please tell me if this is a really bad idea.
>> 
>> Our alternative is to use one 4TB disk for commit log and one for
>> data. Of course this will give us only half the space.
>> 
>> Thanks
>> David
> 

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