CentOS - May 2011 - SSD for Centos SWAP /tmp & /var/ partition

Has anyone actually used a SSD in a Centos setup?

My little experiment with a s/h WD drive for /tmp and SWAP 
partitions kicked the bucket on Wednesday, when the poor WD 
drive caught the click-of-death. It was a s/h drive 
to start with and lasted about 4 months. But that was 
without the /var/log/ partition being written to it, as I 
mounted that back onto /var/log from the original drive.

So I had to install another (WD) drive, and repartion it and 
rebuild my RPM package database, from the backed-up Packages 
file. That seems to be all OK now.

I'm wondering if it would be a good idea to use a new SSD 
for moving all the disk i/o to, that Linux likes to do so 
often. Plus putting SWAP onto a decent SSD should speed 
things up somewhat.

Here's a short video of a laptop fitted with a SSD drive 
booting macOS, compared to a similar laptop booting from 
the standard HDD.

The laptop with the SSD boots and loads some apps in 28 
seconds. The other one takes twice as long.

http://eshop.macsales.com/shop/SSD/OWC/Mercury_Extreme_Pro_6G/?utm_source=thessdreview&utm_medium=banner&utm_campaign=042111

Kind Regards,

Keith Roberts

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2011/5/20 Keith Roberts <keith at karsites.net>:
> Has anyone actually used a SSD in a Centos setup?
Yes.

> I'm wondering if it would be a good idea to use a new SSD
> for moving all the disk i/o to, that Linux likes to do so
> often. Plus putting SWAP onto a decent SSD should speed
> things up somewhat.
Just buy fastest ocz drive than you can find from stores.
>
> Here's a short video of a laptop fitted with a SSD drive
> booting macOS, compared to a similar laptop booting from
> the standard HDD.
>
> The laptop with the SSD boots and loads some apps in 28
> seconds. The other one takes twice as long.
So, slow? My macbook pro with ocz ssd boots much faster :)

--
Eero

On 05/20/2011 01:26 PM, Keith Roberts wrote:
> I'm wondering if it would be a good idea to use a new SSD
> for moving all the disk i/o to, that Linux likes to do so
> often.
Yes, it's often a really good idea.  If you're doing software RAID on 
Linux, you really should either disable disk drives' write cache or have 
the system on a UPS with monitoring and automated shutdown.  Most people 
will opt for the latter.  Using an SSD can boost write performance and 
reliability for other systems.  I just found this write-up on the topic:

http://insights.oetiker.ch/linux/external-journal-on-ssd.html
> Plus putting SWAP onto a decent SSD should speed
> things up somewhat.
Well, only if you're using swap space.  If that's the case, adding RAM 
to the system will probably be less expensive and a lot more effective.

Keith,

On Friday, May 20, 2011 you wrote:
> I'm wondering if it would be a good idea to use a new SSD
> for moving all the disk i/o to, that Linux likes to do so 
> often. Plus putting SWAP onto a decent SSD should speed 
> things up somewhat.
As far as I understand, SSD are fast at reading and slow at writing.
They are strong if data rarely changes and if it is mainly read like root
partitions.

This may be useful for webservers that hold the content in /var/www.

Putting your often changing data like swap and /var/log on a SSD may
slow down your system.

A swap partition is used to save expensive RAM. Don't use much more
expensive FLASH-ROM to replace it.

Beside that, if your system is heavily swapping, a SSD will wear out
quickly.


best regards
---
Michael Schumacher
PAMAS Partikelmess- und Analysesysteme GmbH
Dieselstr.10, D-71277 Rutesheim
Tel +49-7152-99630
Fax +49-7152-996333
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