To upgrade to XFS or not to upgrade, that is the question

[ShangHangin]

I am going to be expanding my array starting with a replacement of my parity drive and swapping out a few drives along the way.  I am running 6.3.5 RFS.  I have a 21TB array made up of 3- 3GB drives, 6-2GB drives, 500MB cache.  My plan was to bump the parity to a 4GB, replace a couple of the older 2GB with 4GBs, move one of the 2GB's as a cache drive.

 

My question to the experts:  Is it worth going through the trouble to convert to the XFS file system?  If so, is this the time to do it?

 

I look for thoughts from the community.

 

Thanks,

 

[BRiT]

It was nearly required for my system to convert to XFS from ReiserFS to stop all the issues it was having. I did this years ago, so maybe the RFS support has improved since then, but in the betas when XFS first showed up it seemed like RFS consistently caused trouble.

[tdallen]

Nearly mandatory, I'd say.

[JorgeB]

7 hours ago, ShangHangin said:

Is it worth going through the trouble to convert to the XFS file system?

 

Always

[ShangHangin]

Thanks for the comments.  I am planning to move forward on this.

 

From a planning standpoint, I am going to first upgrade my Parity drive, re-establish parity, then roll through the drives in the following order.  For most drives, the new "destination" drive is larger than the current drive.  In the end, I will have 3 "leftover" 2GB drives.

 

Let me know if you see any holes in the plan or any "gotchas" to the conversion.

 

 

[Lev]

I'm always like WTF when I see these posts, but then a zen like calm takes over me. WHAT IF?... there was a parallel universe in which I or you had  never ran into the trouble caused by RieserFS, and therefore never had a need to question it? ReFS for life? What is this XFS? I'd like to visit that universe. It's nice to meet you @ShangHangin, you've traveled far and yet not so far.

 

To answer your questions... yes make the move to XFS ! Go to 99% disk full with XFS, it won't have the trouble that ReFS did in high disk space utilization.

 

Second question isn't something you asked but it's my question. Why in your parallel universe would you buy 4TB drives in this day and age? Or are these leftovers? Leftovers = OK ! But if you putting out some $ then please find 8TB's, you can get two 8TB to do what you need vs 3x4TB per your plan.

 

@ShangHangin very happy to see you post after being gone so long. Welcome back 

 

 

 

 

[ShangHangin]

@Lev Yes, I have come so far yet have a long journey ahead of me.  Since I have been using unRaid, I have never had an issue with RFS.  Most likely luck, but I continue to be "Grasshopper" like in the ways of Linux.  Many thanks for your sage advice - more options to consider in my quest.

[trurl]

47 minutes ago, ShangHangin said:

Thanks for the comments.  I am planning to move forward on this.

 

From a planning standpoint, I am going to first upgrade my Parity drive, re-establish parity, then roll through the drives in the following order.  For most drives, the new "destination" drive is larger than the current drive.  In the end, I will have 3 "leftover" 2GB drives.

 

Let me know if you see any holes in the plan or any "gotchas" to the conversion.

 

 

 

I'm a little concerned about this "plan", because it doesn't actually address changing the filesystem of any disks.

 

Do you know what is involved in changing filesystems?

[trurl]

And this part of what you said also makes me wonder if you know what to do:

1 hour ago, ShangHangin said:

I am going to first upgrade my Parity drive, re-establish parity

The usual way to upgrade parity is to just replace the parity drive with a larger drive. When you do this unRAID will rebuild parity. So there is no separate re-establish parity step involved.

[ShangHangin]

@trurl   Sorry for my poor choice of words regarding parity.  As I plan to increase drive sizes during the conversion process, my planned first step is to upgrade the Parity drive and let unRaid rebuild on the larger disk.  After that is complete, then move onto to the file system change process by using a blank drive (pre-cleared) formatted to XFS, and copying data over following the "Mirror each disk with rsync, preserving parity" process.   I plan to use this process because I have a mix of user share and excluded drive.

 

I hope I am on the right track.

 

[BobPhoenix]

@Lev ReiserFS was a great files system for data security with a 32 bit kernel.  The recovery tool cannot be beat.  I tried to build parity on a full 2TB cache drive and stopped the build after a couple of minutes and was able to recover ~90% of my files on the ReiserFS disk.  I could put up with the slow writes when it gets full as long as my data was safe and easy to recover from file system errors.  But you are correct about ReiserFS and unRAID 6 as I've seen numerous posts about problems where the solution was to switch to XFS or BTRFS.  64 bit kernels and ReiserFS just don't work well together.  Just wish XFS recovery tools were as good as the ReiserFS tool.  I lost 4TB when recovery failed on an XFS drive (the -L option on XFS_REPAIR made the drive completely unreadable and I didn't have time to make a backup first like I usually do before I do a repair - my bad) and BTRFS has been no better.  I had to restore my BTRFS cache pool from backup when recovery failed for that.  Of course the BTRFS problem could have been the incompatibility between my hardware and 6.4.  I've never had crashes with 6.3.5 and earlier which likely caused the cache pool to become unrecoverable when I tried 6.4.

[lionelhutz]

Your plan sounds fine.

 

I would also recommend you look at 8T drives. I know they cost more, but the $/T is about the best for a 6T and very close behind is the 8T drive. You will likely pay more per terabyte for a 4T drive then either the 6T or 8T unless you get them on sale for a deal. It would cost more to add 2 x 8T drives compared to 3 x 4T drives, but if you add another 8T drive the cost of that 8T will be less then adding yet 2 more 4T drives.

 

 

 

10 hours ago, BobPhoenix said:

ReiserFS was a great files system for data security with a 32 bit kernel.  The recovery tool cannot be beat.  

 

RFS was a great file system. If it wasn't for the developers trouble it likely would still be one. But, it got pushed to the side and others have passed it.

[Lev]

On 10/22/2017 at 5:54 PM, BobPhoenix said:

XFS or BTRFS.  64 bit kernels and ReiserFS just don't work well together.  Just wish XFS recovery tools were as good as the ReiserFS tool.  I lost 4TB when recovery failed on an XFS drive (the -L option on XFS_REPAIR made the drive completely unreadable and I didn't have time to make a backup first like I usually do before I do a repair - my bad) and BTRFS has been no better

 

What you said there pretty much sums up my feelings on the matter too. Each has there + or - in relation to each other. 

 

Honestly though I look back after having bought a serious UPS system about two years ago my file-syste  issues are like next to nothing.  I strongly recommend a UPS for anyone.

 

If anyone reading this doesn't have money for a UPS, just hold back on that next easystore HD purchase, delete some of your linux ISOs to make some free space to get you by a little longer and go buy the best over-sized UPS you can afford.