Hello, I have a btrfs filesystem which has been working ok for about 90days, but on Monday it become very slow (takes about 6hours to rsync backup a 3GB Ubuntu server - despite minimal changes from previous backup). I noticed, that even with no processes reading or writing to the filesystem, that btrfs-transaci was writing to the disk (averaging at about 5MB/s) for a few hours before stopping until I wrote to the filesystem again and then the process would repeat. The btrfs filesystem uses skinny-metadata and is mounted with relatime It has 744 subvolumes (of which about 700 are readonly snapshots) Any ideas? Is there some sort of cleanup getting automatically run in the background? * Linux hutton-cis.cc.strath.ac.uk 3.16.0-30-generic #40~14.04.1-Ubuntu SMP Thu Jan 15 17:43:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux * Btrfs v3.12 * Label: none uuid: a3e49694-a66d-4c0d-b5bd-d2b7ced68535 Total devices 1 FS bytes used 4.59TiB devid 1 size 8.76TiB used 4.77TiB path /dev/dm-0 * Data, single: total=4.41TiB, used=4.41TiB System, DUP: total=8.00MiB, used=544.00KiB System, single: total=4.00MiB, used=0.00 Metadata, DUP: total=186.00GiB, used=184.17GiB Metadata, single: total=8.00MiB, used=0.00 unknown, single: total=512.00MiB, used=16.30MiB * There is nothing logged in dmesg except for the standard boot messages Thanks for any help anyone can be, -- Ian Gordon, Department of Computer and Information Sciences, University of Strathclyde. Tel: 0141 548 3592 Fax: 0141 548 4523 Room: LT1307 The University of Strathclyde is a charitable body, registered in Scotland, with registration number SC015263. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
