I’m running on v7.2.4 pro with dual parity drives and no slots left. I have a couple of items I wish to address. Looking for best approach guidance. I’m comfortable replacing disks. I’ve read the xfs v4 upgrade process.

Recent upgrade identified 2 v4 xfs disks. I’ve started to move data off those with the intention of reformatting them. I have a parity disk I wish to upgrade and one of those xfs disk will get swapped for larger disk. I also keep cold spares handy. I do not need to reuse what I plan to upgrade. Space is limited but I’m sure I can juggle. I have multiple backups of data I can’t lose so not worried there.

Minimizing downtime is my primary concern. I would typically run mover to satisfaction, shut down, pull disk, add new disk, start array, rebuild disk and repeat as needed. Just the xfs issue has me questioning the approach .

I’m thinking best approach is move data off xfs disks, change format of both xfs disks, let that process complete and then replace parity, then replace the small old xfs disks. What do the good people here suggest?

All advice is appreciated, thank you for reading.

I think it's important to share findings with the community. I did figure out a way forward.

Yesterday I proceeded to reformat the smaller of the two v4 xfs disks. Disk had already all content removed. It was quick, parity was not touched. Completed without issue. It took seconds.

Last night I started to move data off the 2nd disk. It will be done by the time I get home later today. I'll reformat following wiki instructions. Same process I did for the smaller disk. That fixes the v4 issue.

I'm still on the fence on selecting the parity upgrade or parity swap. I need to chew on that a bit. I'm learning toward upgrading parity. I suspect that will allow for the most uptime. I'll just disable mover until it's done. I can upgrade the smaller data disk once parity build completes. Whatever I decide it's happening tonight.

On 5/3/2026 at 10:11 AM, daniel.boone said:

dual parity....

... a parity disk I wish to upgrade and one of those xfs disk will get swapped for larger disk.

No data disk can be larger than either parity disk.

Assuming you will not be using a new data disk larger than either parity disk, since you have dual parity, you can rebuild 2 disks at the same time, whether parity or data. So you could replace one parity and one data disk at the same time.

Started Parity 2 upgrade/rebuild is underway. Its taken a bit of time to juggle data around but its done. Once this completes I'll have dual parity of the same size. I had a mismatch previously which kept me from going beyond a certain size.

@trurl, Its exactly why I had to upgrade the 2nd parity disk. Parity build takes a long time so I anticipate the last of the current disk upgrades to happen next week. I've done so many disks swaps at this point that process doesn't worry me.

Quick recap..

Problem was dual parity drives of different sizes. Latest upgrade identified 2 xfs v4 disks. I was planning to fix my parity but the xfs disk support issue added a wrinkle I had not previously dealt with. I wasn't sure which approach was best for uptime while minimizing the disk wear. I anticipated multiple parity builds during this. I could have not been more wrong.

My solution..

I started by upgrading an array disk, non v4, to make room. Moved data off one of the v4 disk, reformatted, repeated process for for the 2nd xfs v4 disk. I was pleasantly surprised that formatting was quick and did not impact the parity. Once dust settled I proceeded to upgrade my smaller parity disk. That leaves one disk to upgrade after parity is recreated. Process took time but my array has been running the entire time minus the reboots/shutdowns I had to do during the disk upgrade process. Wish you all well. Thanks for reading. Consider this one done..

On 5/6/2026 at 11:55 AM, trurl said:

No data disk can be larger than either parity disk.

In the case where you have dual parity and are upgrading a parity disk, only the size of the parity disk not being rebuilt matters, since the rebuilding parity disk is invalid until rebuilt. The valid parity disk can rebuild a single data disk as long as it is not larger than the valid parity disk.

The invalid 2nd parity disk can be built as long as there is no more than one invalid disk in the array.

You can rebuild both parity if no data disks are invalid.

You can rebuild one parity and one data disk if the other parity and all other data disks are valid.

You can rebuild 2 data disks if both parity and all other data disks are valid.

No data disk can be larger than any valid parity disk.

So, you still could have rebuilt both at the same time.

4 minutes ago, trurl said:

You can rebuild one parity and one data disk if the other parity and all other data disks are valid.

...

No data disk can be larger than any valid parity disk.

I should note, however, that I have not tried this myself. It is even possible it won't allow you to do it even though it should work. I wonder if @JorgeB has tested that scenario.

8 minutes ago, trurl said:

I should note, however, that I have not tried this myself. It is even possible it won't allow you to do it even though it should work. I wonder if @JorgeB has tested that scenario.

Yes, this is possible, as long as the other data disks and the other parity are valid.

Thanks, I actually have done the parity swap in the past. If I recall for at least prior versions the system was unavailable for a portion of the process. My first priority here was uptime so I wasn't ready to commit to that approach.

I have some experience with the product. I think my first version of unRaid was 4. Even so I still ask here when things are not clear to me, especially on new functionality. What threw me here was the xfs v4 upgrade. As mentioned that was super easy, fast and I experienced no down time.

My parity drive 2 upgrade completed yesterday. Over the weekend I'll pull the oldest drive, rebuild and with that all changes will be done. Drives are now on the latest xfs version. I'll have completed 3 drive swaps at that point. I have enough free space that I can wait for sale prices on a drive purchase.

Thanks all for the guidance.

6 hours ago, daniel.boone said:

have done the parity swap in the past. If I recall for at least prior versions the system was unavailable for a portion of the process

Parity swap was not involved in this scenario. It is for upsizing parity when you already have a disabled data disk, so you can use a larger disk to upsize parity and use the original parity to rebuild the data disk.

Parity swap copies parity to the new parity disk, so the array has to be offline during the copy so parity can't change. Then the array can be online again for the data disk rebuild to the original parity.

Also, reviewing the thread. Not clear whether you were considering rebuilding an XFS V4 disk. Of course, that rebuild would have resulted in an XFS V4 disk.