disparty - another RAID4 tool

OK, in my search for RAID4 parity based protection utilities, I stumbled upon disparity. It is like SnapRAID, only simple enough that I can understand its command line. It is also still actively being worked on (albeit after a long pause). The next version will contain its own GUI, but for now you can either download the utility itself here:

http://www.vilett.com/disParity/forum/topic.php?id=94


Or download the GUI which also has the utility built in here:

http://student.fau.edu/pbryan/web/dsm/



I am going to remove SnapRAID and test this one out. Anyone currently using disparity?

Out of curiosity, what does dual parity drives gain you?

EDIT: If you use the DisParity Storage Manager (the GUI), you can have more than one parity drive:
http://student.fau.edu/pbryan/web/dsm/
Edited by cybrsage - 10/15/12 at 8:01pm

Does no one use this?

Development has restarted...though I have to say I newly discoverd the software. I like its easy to understand syntax, for example:

How to update the backup:

1. Open a command prompt, cd to the directory where you installed disParity,
and type "disparity update". Any files deleted since the last snapshot or
update will be removed from the parity. Any new files added since the last
snapshot or update will be added to the parity. Edited files will also
be updated.

How to recover a lost drive:

1. Open a command prompt, cd to the directory where you installed disParity,
and type "disparity recover [num] [dir]" from the command line. [num] is
the drive number to recover. [dir] is the location where you want the
recovered files to be written. This location must have enough space to
store the recovered data, or else disParity will eventually run out of disk
space and abort. An example might be "disparity recover 2 C:\data\" which
will restore whatever files were on drive #2 to the folder C:\data.
2. Check the log file and make sure that disParity reported "Hash verified" for
all of your recovered files.


How easy is that?

AFAIK, it only works via the third party GUI (to use two parity drives). A new version with a built in GUI will be coming out in a few months - it is currently being worked on.

A new version of disparity is in beta and it is MUCH nicer. It now has a built in GUI. If you want to try it out, go here:

http://www.vilett.com/disParity/forum/topic.php?id=156

I ran into an issue after the install, since I am upgrading from a previous version - I had to reboot after the install but the procedures did not mention that. I would reboot after install regardless, just to be sure. So far, I like the changes.

DisParity is now on beta 0.28.

http://www.vilett.com/disParity/beta.html

Beta 0.29 has been released.

http://www.vilett.com/disParity/beta.html

If you have never tried disparity, you should. If you tried it in the past, it is a VERY VERY VERY different animal now - you should try it again.

Dunno, I only own one 3TB drive I am willing to toss aside for use as the parity drive. Why do you want multiple parity drives?

AFAIK, disparity does not do realtime raid (at least if it does I have not seen it) and only does snapshot raid. So basically, you are saying you guys use two parity drives in case one parity drive fails at the same time a data drive fails. Is that correct? Wouldn't running a batch file to copy the changed files do the same thing? Something like:

@echo off
REM Copy parity files
@echo Copying Parity Files to Secondary Drive
xcopy Z:\*.* Y:\*.* /e /c /r /y
@echo Copy Complete
pause
exit

With Z being your primary parity drive and Y being your secondary parity drive, and running the batch file after the sync is complete. I have never seen the need for two parity drives, but that does not mean others do not. Just curious is all.
Edited by cybrsage - 12/26/12 at 12:52pm

Beta .30 has been released:

http://www.vilett.com/disParity/beta.html

This one adds the ability to restore individually deleted files, provided you have not run the sync since then.

Oops, wrote that backwards. It DOES do snapshot, not realtime. My bad, I will edit the previous post.

I do not understand how having two parity drives will help you if you change something and then lose a drive prior to the sync. Why would two parity drives help you in that instance? It would appear that neither one would be updated if you did not yet sync.

I am a bit confused still. Is the 1 and 2 the two parity drives or two of the data drives?

Wouldn't the parity info on the two parity drives be the exact same info? Why would having two copies of the same thing be of any help?

From what I can tell of disParity (maybe I should ask the author, eh?), it appears it knows what is on each drive, that it does not lump them all together. When I run a scan, it tells me the differences for each data drive and then it updates based on that one data drive based on the individual files. When I remove a data drive from the set, it goes through and deletes the parity based on the protected files. Since I have mostly ISO's of BluRays, the files are quite large. This means I can watch it as it runs. It tells me the number of adds, changes, and deletes since the last run, per data drive. When I say to update, it creates the parity info while scanning each file (it lists the file it is currently working upon). When you remove the drive, it does the same thing in reverse.

I will read up more on RAID4 Parity and how it works, it is quite possible I just do not understand.

DisParity has been updated again. One of the things added (has been there for a few revs and I did not notice) is that you can recover individual files now...called Undelete by the program. You can decide where to put them too, you do not have to recover them to the drive they originated on. Current rev is:

Beta 0.34 is up and running. http://www.vilett.com/disParity/beta.html

Disparity is up to beta 0.35 now:

Changes in version 0.35 beta released Monday, January 14, 2013
•Fixed bug where errors accessing the root of a drive during a scan were not reported in the UI.
•A warning is now displayed when trying to set the temp folder to a location on the parity drive.
•Scanning of the parity folder itself is now prevented.
•The log file now lists the time to completion for long running tasks like update and verify.
•Fixed a sporadic crash bug in Reset.


http://www.vilett.com/disParity/beta.html

AH, ok, I understand what you are saying. I can see some people wanting that, I personally do not want to lose two 4TB drives to parity alone.

I have been using it quite some time now, it works well. You can recover and entire drive or undelete some or all of the files you deleted between now and your last sync job.