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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.
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?
Thank you very much
brettesinclair
715 Posts
1
October 19th, 2016 05:00
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
208 Posts
0
October 19th, 2016 23:00
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
DukeR1337
208 Posts
0
November 1st, 2016 06:00
Hi
Can you let me know about this?
Cheers
eastman3
2 Posts
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November 2nd, 2016 01:00
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
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日期: 2016/11/02 下午 04:07
主旨: Re: - Quick verifcation regarding Fast Cache
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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 ?
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brettesinclair
715 Posts
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November 2nd, 2016 01:00
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 ?