Author Topic: Understanding the limitations of Snapshot RAID  (Read 15721 times)

Offline naeonline

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Re: Understanding the limitations of Snapshot RAID
« Reply #15 on: April 06, 2012, 01:10:21 pm »
Is this recycle bin you are refering to the URU?

Offline Brahim

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Re: Understanding the limitations of Snapshot RAID
« Reply #16 on: April 07, 2012, 02:23:04 pm »
Is this recycle bin you are refering to the URU?

No.
Snapshot RAID in Cruise Control mode has a special option for recycle bin.
Please read the wiki post as it touches on the use of that recycle bin feature.

Offline JazJon

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Re: Understanding the limitations of Snapshot RAID
« Reply #17 on: July 28, 2012, 08:05:31 am »
What if we want to only use FlexRaid SnapShot, and not FlexRaid pooling too.  I'm going to use Drive Bender for the pooling. (duplication disabled) and then use SnapShot raid for protection.    Should I schedule the Update for more often then once a day?  The drives will have Videos/Pictures/Music only on them.

P.S. I was trying to better understand how parity raid works and found this great article
http://riceball.com/d/content/raid-5-parity-what-it-and-how-does-it-work

Offline JazJon

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Re: Understanding the limitations of Snapshot RAID
« Reply #18 on: July 30, 2012, 05:05:01 pm »
Does FlexRaid actually write any data to the DRU's?  (or is it all on the PPU + DataBase file on C:)

My understanding is Files protected by standard raid parity will no longer be standard NTFS files, they will be "file parts" that are spread across multiple hard drives that will look garbled outside of the pool.    Is FlexRaid different?  I'd like to better understand how Snap Raid works given the previous sentence and the other link in my last post.

Also, is it possible to use SnapShot Raid in Cruise Control if you don't want to use Pooling?    I couldnt figure out how to use SnapShot only mode in Cruise Control, so I set it up via Expert mode for now.   I'm assuming the special  recycle bin option is only when you're using FlexRaid pooling so maybe that's why Cruise Control is a Raid  + Pooling combo option only.
« Last Edit: July 30, 2012, 05:08:38 pm by JazJon »

Offline m0t0k0

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Re: Understanding the limitations of Snapshot RAID
« Reply #19 on: July 31, 2012, 03:29:34 pm »

You are correct flexRAID just examines the DRUs and calculates parity data which is written to the PPU. As such the DRUs remain untouched NTFS volumes and can be read interdependently in any other system

Normal RAID implementations stripe that data and parity over multiple disks

Again you are correct as far as I know Cruise control consists of RAID and pooling. The recycle bin is not affected unless the drives are pooled
WHS 2011
Transparent RAID

Offline lc123

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Re: Understanding the limitations of Snapshot RAID
« Reply #20 on: December 20, 2012, 07:05:02 am »
I don't really want to use pooling at all but I want the Flexraid recycle bin which currently only works with pooling. If I understand how it works now:
In a non-pooled environment, without using the flexraid recycle bin, whenever files are deleted, the data is compromised until the parity is rebuild??

So what happens if you delete a bunch of files and then start to rebuild the parity, and then during the rebuild a drive goes bad? Isn't that a problem? Without the flexraid recycle bin, will some data be lost?

It seems like just deleting ANY files on the raid, it is possible that if a drive goes bad before the rebuild of parity is totally completed, you could loose data. Is that true?

It seems like the Flexraid Recycle Bin should be added to the Data Protection product without pooling. Because without the Flexraid Recycle Bin, Snapshot Raid doesn't seem to be completely safe.


Offline uhthome

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Re: Understanding the limitations of Snapshot RAID
« Reply #21 on: October 06, 2014, 07:21:42 am »
Hi,
I have one question regarding the recycle bin feature of Flexraid:
I am using a snapshot raid in cruise control on WHS 2011 and the recycle bin featrue is turned on. The windows recycle bin is disabled for the drives in the pool as well as for the pooled drive V:\.

The wiki says: Editing a file in the pool will compromise recovery in the event that a drive fails, but deleting a file is no problem because the deleted file is saved in the flexraid recycle bin feature until the next parity update.

Therefore, instead of just editing a file, can I avoid a compromised recovery by deleting the file (so it goes to the recycle bin) and then write a new version to the pool unter the same name? This procedure should do the same to the file as editing, but a copy of the old version should be in the Flexraid recyvcle bin in case a recovery is needed for a faile drive. Or does the new file, carrying the same name, interfere with the recovery mechanism?

Is this procedure a good solution to maintain data integrity in case a file needs to be changed, or not?

« Last Edit: October 06, 2014, 03:20:42 pm by uhthome »