On 2015-08-04 13:36, John Ettedgui wrote: > On Tue, Aug 4, 2015 at 4:28 AM, Austin S Hemmelgarn > wrote: >> On 2015-08-04 00:58, John Ettedgui wrote: >>> >>> On Mon, Aug 3, 2015 at 8:01 PM, Qu Wenruo wrote: >>>> >>>> Although the best practice is staying away from such converted fs, either >>>> using pure, newly created btrfs, or convert back to ext* before any >>>> balance. >>>> >>> Unfortunately I don't have enough hard drive space to do a clean >>> btrfs, so my only way to use btrfs for that partition was a >>> conversion. >> >> If you could get your hands on a decent sized flash drive (32G or more), you >> could do an incremental conversion offline. The steps would look something >> like this: >> >> 1. Boot the system into a LiveCD or something similar that doesn't need to >> run from your regular root partition (SystemRescueCD would be my personal >> recommendation, although if you go that way, make sure to boot the >> alternative kernel, as it's a lot newer then the standard ones). >> 2. Plug in the flash drive, format it as BTRFS. >> 3. Mount both your old partition and the flash drive somewhere. >> 4. Start copying files from the old partition to the flash drive. >> 5. When you hit ENOSPC on the flash drive, unmount the old partition, shrink >> it down to the minimum size possible, and create a new partition in the free >> space produced by doing so. >> 6. Add the new partition to the BTRFS filesystem on the flash drive. >> 7. Repeat steps 4-6 until you have copied everything. >> 8. Wipe the old partition, and add it to the BTRFS filesystem. >> 9. Run a full balance on the new BTRFS filesystem. >> 10. Delete the partition from step 5 that is closest to the old partition >> (via btrfs device delete), then resize the old partition to fill the space >> that the deleted partition took up. >> 11. Repeat steps 9-10 until the only remaining partitions in the new BTRFS >> filesystem are the old one and the flash drive. >> 12. Delete the flash drive from the BTRFS filesystem. >> >> This takes some time and coordination, but it does work reliably as long as >> you are careful (I've done it before on multiple systems). >> >> > I suppose I could do that even without the flash as I have some free > space anyway, but moving Tbs of data with Gbs of free space will take > days, plus the repartitioning. It'd probably be easier to start with a > 1Tb drive or something. > Is this currently my best bet as conversion is not as good as I thought? > > I believe my other 2 partitions also come from conversion, though I > may have rebuilt them later from scratch. > > Thank you! > John > Yeah, you're probably better off getting a TB disk and starting with that. In theory it is possible to automate the process, but I would advise against that if at all possible, it's a lot easier to recover from an error if you're doing it manually.