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DukeR1337
2 Iron

Quick verifcation regarding Fast Cache

Hi everyone

Unfortunately usually I only deal with 3x Fast Cache disks 100 GByte in size each. Usually I take two to create a Fast Cache with a size of 100 GByte and one is left as hotspare.


As far as I know Fast Cache is always RAID 1 and as soon as 1 disk is broken and there is no HS the write cache for the Fast Cache is diabled.

We now have a EMC VNX 5300 where we ordede 5x 200 GByte disks for Fast Cache. My idea was to design a Fast Cache with 4x 200GB disks and take one as HS. Which means 4x 200 GB devided by 2 (RAID 1) = 400 GB Fast Cache.

Based on the fact sheet the maximum amount for a VNX 5300 is 500 GB Fasts Cache by using 10x 100 GByte.

https://www.google.ch/search?q=emc+fast+cache&biw=1266&bih=842&source=lnms&tbm=isch&sa=X&sqi=2&ved=0...

What I don't understand and that is the actual infrmation I need. Is Fast Cache using RAID 1 then or RAID 10? Is it possible to create 1 RAID 1 with more than 2 disks? Or do I have to create 2x RAID 1 Fast Cache (if this is possible).


I've nevere did that before and it would be really good to know about the technical concept and how to do it?

Is there more effort of configuration when using 4 disks instead of 2? Or is it just clicking "Create" and add all disks needed?

https://www.google.ch/search?q=emc+fast+cache&biw=1266&bih=842&source=lnms&tbm=isch&sa=X&sqi=2&ved=0...

https://www.google.ch/search?q=emc+fast+cache&biw=1266&bih=842&source=lnms&tbm=isch&sa=X&sqi=2&ved=0...

Thank you very much

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5 Replies
brettesinclair
3 Silver

Re: Quick verifcation regarding Fast Cache

Fast CACHE is created as RAID1.

You can 'point and click' create it in the gui but the order you select the drives determines the Primary and Secondary drives for the mirror(s).

Check the best practice doc for guidelines;

https://support.emc.com/kb/442856

DukeR1337
2 Iron

Re: Quick verifcation regarding Fast Cache

Hi

Thanks for your feedback. Does that mean I have 1 big RAID1 one out of 4 disks or two RAID 1 with each 2 disks?

Cheers

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DukeR1337
2 Iron

Re: Quick verifcation regarding Fast Cache

Hi

Can you let me know about this?

Cheers

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brettesinclair
3 Silver

Re: Quick verifcation regarding Fast Cache

The disks are grouped in pairs so I suppose it's really grouped R1's or mirrors.

There's no striping thought so don't confuse with R10.

Why is the definition so important to you ?

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eastman3
1 Copper

Re: Quick verifcation regarding Fast Cache

Hello,

I did not request the verification, so I do not know why my name was

there.

Please cancel this if I made something wrong.

Thank you.

Sincerely,

Eastman Yi 易正淋

Product Manager, Enterprise Information Service Div

LEALEA TECHNOLOGY CO., LTD.

力麗科技股份有限公司

系統服務事業部

+886-910-389-079

+886-2100-2458 # 8594

eastman@llt.com.tw

台北市松江路162號7樓

寄件者: "P@rity99" <emc-community-network@emc.com>

收件者: "eastman@llt.com.tw" <eastman@llt.com.tw>,

日期: 2016/11/02 下午 04:07

主旨: Re: - Quick verifcation regarding Fast Cache

DECN

Quick verifcation regarding Fast Cache

reply from Brett@S in VNX - View the full discussion

The disks are grouped in pairs so I suppose it's really grouped R1's or

mirrors.

There's no striping thought so don't confuse with R10.

Why is the definition so important to you ?

Reply to this message by replying to this email, or go to the message on

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