Author Topic: cache Drive possible ?  (Read 2213 times)

Offline MasterCATZ

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cache Drive possible ?
« on: April 19, 2013, 09:41:11 pm »
I am planing on moving from ZFS Raidz to flexraid

mostly because if their is a massive fail I can still recover files the second being I like the sound of LESS HDD's needing to run when only accessing 1 file

my current ZFS system consists of 2 x 24 hdd racks and 1x 16 hdd rack

I am planing on giving flexraid a go with my 16x hdd system as I was about to replace it from 2tb with 3tb HDD's

because of the way zfs worked I used an 4 gig DDR RAM drive for an log drive that I would like to still make use off ( apart from that i might just make it a swap drive as its to small to use for anything else)

or is it possible to still use my SSD cache drives to speed things up ?


 

Offline Brahim

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Re: cache Drive possible ?
« Reply #1 on: April 19, 2013, 10:16:26 pm »
The SSD will be useless in FlexRAID.
What you could do is place your small files on it or anything that needs quick access. That or use it as a scratch disk.

Offline MasterCATZ

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Re: cache Drive possible ?
« Reply #2 on: April 20, 2013, 05:09:12 am »
Actually now that I finally gotten flexraid to work on ubuntu ( held up by permission errors ) and being used as XBMC HTPC


I am wanting to know if URU does what I am hoping it does is this going to act as a scratch disk ?

I am thinking

DRU ( data disk )
PPU ( redundancy )
URU scratch disk where data is dumped onto until a scheduled RAID-F is performed


just dumped my first 40 gig file to see what happens and noticed data went onto the first DRU
I am assuming the next file sent will go onto the next DRU

and I am assuming if I add an URU that the files will go their until I do an RAID-F then spread them across the DRU's ?




Offline Brahim

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Re: cache Drive possible ?
« Reply #3 on: April 20, 2013, 06:09:12 am »
There is no cache drive as although FlexRAID has high performance, it is not a performance oriented solution.
If you want super high performance, you will need to go with a striped RAID.

A cache drive is just not necessary in FlexRAID as in the worst case scenario, you get the performance of a single drive, and in the best case scenario, you get RAID-0 performance.

What you can do, is add the SSD to the array and place content that need fast SSD type speed into it.
Before adding the SSD to the array, create a folder on it so you know how to locate that SSD specifically within the array.