I started a simple backup like Ive done many times. Both pools local, backup pool empty, usual zfs send -R | zfs receive of a current snapshot.
The first 18 TBs ran normally, took just under an hour per TB. gstat showing the target disks pounding - like 300 MB/sec writes. I went away, came back later. It's now been on 22.0 TB to 22.4 TB for about a day. gstat is showing something like *KB* of write a sec not hundreds of MB.
2 source disks being read, out of the 14 or so in the source pool, and they're just 0.3% and 0.5% busy respectively.
The server is otherwise as far as I can tell, totally idle. zpool status -v shows no issues/errors.
50 minutes for each of the first 18 TB, then suddenly today almost no speed at all.
Where do I begin to diagnose and fix whatever's up?
The first 18 TBs ran normally, took just under an hour per TB. gstat showing the target disks pounding - like 300 MB/sec writes. I went away, came back later. It's now been on 22.0 TB to 22.4 TB for about a day. gstat is showing something like *KB* of write a sec not hundreds of MB.
2 source disks being read, out of the 14 or so in the source pool, and they're just 0.3% and 0.5% busy respectively.
The server is otherwise as far as I can tell, totally idle. zpool status -v shows no issues/errors.
50 minutes for each of the first 18 TB, then suddenly today almost no speed at all.
Where do I begin to diagnose and fix whatever's up?