Re: Replacing drives with larger ones in a 4 drive raid1

For completeness here's the summary of my replacement of all four 6 TB drives (henceforth "6T") with 8 TB drives ("8T") in a btrfs raid1 volume. I included transfer rates so maybe others can get a rough idea what to expect when doing similar things. All capacity units are SI, not base 2.

Re: Replacing drives with larger ones in a 4 drive raid1

> a "replace" of the 3rd 6 TB drive onto a second 8 TB drive is currently in > progress (at high speed). This second replace is now finished, and it looks OK now: # btrfs replace status /data Started on 16.Jun 01:15:17, finished on 16.Jun 11:40:30, 0 write errs, 0 uncorr. read

Re: Replacing drives with larger ones in a 4 drive raid1

>> So I was back to a 4-drive raid1, with 3x 6 TB drives and 1x 8 TB drive >> (though that 8 TB drive had very little data on it). Then I tried to >> "remove" (without "-r" this time) the 6 TB drive with the least amount >> of data on it (one had 4.0 TiB, where the other two had 5.45 TiB each). >>

Re: Replacing drives with larger ones in a 4 drive raid1

boli posted on Tue, 14 Jun 2016 21:28:57 +0200 as excerpted: > So I was back to a 4-drive raid1, with 3x 6 TB drives and 1x 8 TB drive > (though that 8 TB drive had very little data on it). Then I tried to > "remove" (without "-r" this time) the 6 TB drive with the least amount > of data on it

Re: Replacing drives with larger ones in a 4 drive raid1

> Replace doesn't need to do a balance, it's largely just a block level copy of > the device being replaced, but with some special handling so that the > filesystem is consistent throughout the whole operation. This is most of why > it's so much more efficient than add/delete. Thanks for this

Re: Replacing drives with larger ones in a 4 drive raid1

On 2016-06-12 06:35, boli wrote: It has now been doing "btrfs device delete missing /mnt" for about 90 hours. These 90 hours seem like a rather long time, given that a rebalance/convert from 4-disk-raid5 to 4-disk-raid1 took about 20 hours months ago, and a scrub takes about 7 hours

Re: Replacing drives with larger ones in a 4 drive raid1

Henk Slager posted on Sun, 12 Jun 2016 21:03:22 +0200 as excerpted: > But now that you anyhow have all data on 3x 6TB drives, you could save > balancing time by just doing btrfs-replace 6TB to 8TB 3x and then for > the 4th 8TB just add it and let btrfs do the spreading/balancing over > time by

Re: Replacing drives with larger ones in a 4 drive raid1

On Sun, Jun 12, 2016 at 7:03 PM, boli wrote: >>> It's done now, and took close to 99 hours to rebalance 8.1 TB of data from >>> a 4x6TB raid1 (12 TB capacity) with 1 drive missing onto the remaining >>> 3x6TB raid1 (9 TB capacity). >> >> Indeed, it not clear why it takes 4

Re: Replacing drives with larger ones in a 4 drive raid1

>> It's done now, and took close to 99 hours to rebalance 8.1 TB of data from a >> 4x6TB raid1 (12 TB capacity) with 1 drive missing onto the remaining 3x6TB >> raid1 (9 TB capacity). > > Indeed, it not clear why it takes 4 days for such an action. You > indicated that you cannot add an online

Re: Replacing drives with larger ones in a 4 drive raid1

On Sun, Jun 12, 2016 at 12:35 PM, boli wrote: >> It has now been doing "btrfs device delete missing /mnt" for about 90 hours. >> >> These 90 hours seem like a rather long time, given that a rebalance/convert >> from 4-disk-raid5 to 4-disk-raid1 took about 20 hours months ago,

Re: Replacing drives with larger ones in a 4 drive raid1

> It has now been doing "btrfs device delete missing /mnt" for about 90 hours. > > These 90 hours seem like a rather long time, given that a rebalance/convert > from 4-disk-raid5 to 4-disk-raid1 took about 20 hours months ago, and a scrub > takes about 7 hours (4-disk-raid1). > > OTOH the

Re: Replacing drives with larger ones in a 4 drive raid1

Updates: > So for this first replacement I mounted the volume degraded and ran "btrfs > device delete missing /mnt", and that's where it's been stuck for the past > ~23 hours. Only later did I figure out that this command will trigger a > rebalance, and of course that will take a long time.

Re: Replacing drives with larger ones in a 4 drive raid1

This is somewhat off topic but... 9.6.2016, 18.20, Duncan kirjoitti: Are those the 8 TB SMR "archive" drives? I haven't been following the issue very closely, but be aware that there were serious issues with those drives a few kernels back, and that while those issues are now fixed, the

Re: Replacing drives with larger ones in a 4 drive raid1

On 09.06.2016, at 17:20, Duncan <1i5t5.dun...@cox.net> wrote: > Are those the 8 TB SMR "archive" drives? No, they are Western Digital Red drives. Thanks for the detailed follow-up anyway. :) Half a year ago, when I evaluated hard drives, in the 8 TB category there were only the Hitachi 8 TB

Re: Replacing drives with larger ones in a 4 drive raid1

boli posted on Wed, 08 Jun 2016 20:55:13 +0200 as excerpted: > Recently I had the idea to replace the 6 TB HDDs with 8 TB ones ("WD > Red"), because their price is now acceptable. Are those the 8 TB SMR "archive" drives? I haven't been following the issue very closely, but be aware that there

Replacing drives with larger ones in a 4 drive raid1

Dear list I've had a 4 drive btrfs raid1 setup in my backup NAS for a few months now. It's running Fedora 23 Server with kernel 4.5.5 and btrfs-progs v4.4.1. Recently I had the idea to replace the 6 TB HDDs with 8 TB ones ("WD Red"), because their price is now acceptable. (More back story: