Beginners Guide to Snapshot RAID With FlexRAID 2.0

Hey everybody! I can't help with the coding, but I'm extremely grateful for all the hard work Brahim is putting into this. So, I'm trying to help where I can. I put this guide together, basically a Dummies guide to FlexRAID 2.0 (Snapshot Only) All the information is on the forum here in pieces, I've put it in to one place that will hopefully make it easier for total newbs to get started. I'm a newb myself and this is a work in progress; I would really appreciate any constructive criticism/error corrections from the experts around here. Please, if you don't mind, post any corrections here in this thread So I don't get 10 messages with the same fix!

One big thing the guide is missing is how to add network shares to the array. I know how to mount shares to a drive letter in XP, but I'm running out of drive letters so I'd like to include whatever workaround there is to that problem in the guide. So if somebody could instruct me on adding network shares to the array without mounting them to a drive letter, I'd really appreciate it!

Excellent!

I will work on setting up a new Wiki/knowledge-base site where we can organize all this. I might make that my priority tonight.
In your next revision, make sure to include pictures (lots of them). Many people only read words only if there is a picture next to them.

Again, great work!

Thanks Brahim!

You're absolutely right, it needs screenshots.

I'm planning on getting all the verbage finished and corrected first, then working on adding screenshots to each step.

good job. def add screenshots and maybe a TOC and Appendix.

other than that i don't see any errors in your guide.

Hey Nak, thanks for this! My only question is how do I get a single drive view of my new FlexRAID setup? I think I may need to configure a storage pool as well? Would like to browse to say, K:\ and have that be my pooled DRUs.

- Brian

Hey Brian! Wish I could help, but I'm a newb at this myself. I haven't even lookked at view or pool, just snapshot.

No problem. If I get it figured out, I'll see if I can document it as well!

First off FANTASTIC guide - so simple and easy

.

Just one quick thing, after I setup my DRU's and PPU's, set the appropriate settings you mentioned and hit 'Create' I am getting:

The [<[create]>] task has successfully initiated... Process number: 1

Instead of the Process number: 3 you mentioned in the guide - is this a problem?

Also you don't explain why, I'm sure you know what you're doing but always interested, why are we replacing DEBUG/TRACE with INFO in the properties file?

This message was edited 1 time. Last update was at 04/04/2011 10:30:35

Thanks! It's a work in progress still.

Don't worry about the process number. That's just a running count of how many operations the service has performed since it started. We change "TRACE" to "INFO" to change the level of logging in the log file. If there's a bug, you can use the "TRACE" info to figure out what's going wrong. But there's a lot of information in the file. By changing it to "INFO", it makes it a lot easier for a user to see normal operation of the service. If you have a bug that Brahim--the developer--will need to look at, make sure and change it back to "TRACE" so that Brahim has all the information necessary to debug.

Great questions! I'll add that information to the next revision!

Nak

This message was edited 1 time. Last update was at 07/04/2011 05:43:20

My recommendation for insert:

How does FlexRAID differ from traditional RAID?
Traditional RAID(Redundant Array of Inexpensive Disks) has variety of level and all of them does differ from one to another. Some offer better protection than another, while another may offer better performance. But eventually what all traditional RAIDs are just a block RAID, which mean they all are running in block which has 1 common requirement. All blocks must be in the same sizes and each of the drives must have the same amount of blocks or the lowest common denominator will be used. For more information about what a RAID is, please check the RAID wiki page. What FlexRAID differ from the traditional RAID or block RAID is that it's a data RAID. In other words, RAID or the protection of RAID is done at the data level instead of the block level. Or to paraphrase it, FlexRAID is protecting data instead of block that contain data.

How does FlexRAID works?
Considering the word RAID is in the name, in a way it has to work like a RAID. To be more specific, it works like a parity RAID, eg: RAID 5 or RAID 6. If you want to understand how parity type of RAID works, the same wiki page describe it very well under the "RAID Parity" section. In a layman term (although not accurately describe), this is how a parity RAID works. Say you have 5 drives, and 4 of the drives has a file in it; and FlexRAID call them DRU. Except for last drive which reserve to store parity file or in the FlexRAID case, it's call PPU. If the 4 drives containing data 1,2,3 and 4 and when you sum them all up you has 1+2+3+4=10. So, if you consider the result of 10 to be a parity, even if you missing any one of the number you can reconstruct it. Eg: 1+2+?+4=10, and to solve problem and get the missing value you would simply do ?=10-4-2-1=3. That's a simple mathematics of how RAID works in general.

My recommendation for modification:

What Can FlexRAID do?
FlexRAID has 3 main functions: Snapshot RAID, Live RAID, and storage pooling.

Snapshot RAID takes a picture of your data at one point in time, the point you last performed an update. Any changes since the last update are not protected. Snapshot RAID is best used on data that does not change too often. It’s perfect for large collections of multimedia content. Automatic updates can be scheduled to run every night, or whatever frequency you desire.

Live RAID run in the background and consistently workings its magic to update the protection mechanism when you make any changes, addition or deletion to your data. The upshot is it's intended for the type of data that's being updated frequency in small amount at a time. And it's quite CPU intensive and if you make any error lie deleting a file, well Live RAID won't save you, at least not on it's own. It won't be able to recognize if the deletion of a file is accidental or deliberate.

Storage Pooling is a background service that is actually does not offer any type of data protection at all. Its only purpose is to help you organize your data. There are many way of setting the Storage Pooling, but it's out of the scope for this guide.

This guide will discuss Snapshot RAID only.

So if I make a Snapshot RAID with 3 same disks it won't automatically join 3 the DRUs. How can I join them?

GREAT!
Thanks!

This message was edited 2 times. Last update was at 06/06/2011 12:56:44

Thanks for the very good guide !

now i bit understand what i need

i guess for my situation is Flexraid Snapshot the best choice to install
as most of my drives i use for downloades and shares of movies stored for longer times and dont regulairy changed so much

need to make free a test system to see how things are work before i go play with my regulair system.

edit : i installed Flexraid with sucses on a Win7 system but creating an array wasnt going well , or at least i had some errors
after the creating process there were some lines .... see log , i looked the log.log but its quite long so i have to find out were the errors going.
havnt much time for it yet so i will study for that later.
But what need to do if you see errors in the creating process ?
for now i simple click the 'delete array' button and array was gone, or at least i think so.
hopefully my system wont have any trouble now after doing this.
It might be a problem because the system has already 2 raid arrays and 2 raidcontrollers on it, also its a dual boot config for win7/server 2008 R2 ?

At last i can give a try on another machine but it need some work to prepair it.

Anyway , creating an array wasnt really difficult folowing the short manual and till so far it seems to work
one thing i saw into the creating screen was an option "URU" which is not explained into the manual but it was standard not activated so i leaved this.

I just did some quick tests using this guide and found one strange thing.

My config:
Tx RAID
DRU1 DRU2 DRU3 PPU1

Succesfully created the raid, then manually deleted all files from PPU1 drive.
Then I want to restore it:
Restore: PPU1, click "restore".
Gives an error message, here is the log:

So probably the only working way to restore a PPU is "recreate the raid".