Cgroups-blkio

Anlegen einer Control Group

• cgcreate -g blkio:/mygroup

Checken

• lscgroup | grep blkio:/mygroup

blkio:/mygroup

Welche Parameter sind Subsystem Block-I/O vorhanden

• cgget -g blkio /mygroup

/mygroup:
blkio.throttle.io_serviced: Total 0
blkio.io_service_bytes_recursive: Total 0
blkio.io_serviced_recursive: Total 0
blkio.time:
blkio.io_serviced: Total 0
blkio.reset_stats:
blkio.io_wait_time: Total 0
blkio.weight: 500
blkio.leaf_weight_device:
blkio.throttle.read_iops_device:
blkio.io_merged_recursive: Total 0
blkio.throttle.write_bps_device:
blkio.leaf_weight: 500
blkio.sectors_recursive:
blkio.weight_device:
blkio.io_service_time_recursive: Total 0
blkio.throttle.write_iops_device:
blkio.throttle.io_service_bytes: Total 0
blkio.io_service_bytes: Total 0
blkio.io_wait_time_recursive: Total 0
blkio.io_service_time: Total 0
blkio.time_recursive:
blkio.io_merged: Total 0
blkio.throttle.read_bps_device:
blkio.sectors:
blkio.io_queued: Total 0
blkio.io_queued_recursive: Total 0

Zustand der Drosselung checken

• cgget -g blkio /mygroup | grep blkio.throttle.write_bps_device

blkio.throttle.write_bps_device:

Feststellen der Major und Minor Nummer

• ls -l /dev/sda

brw-rw---- 1 root disk 8, 0 Okt 12 22:24 /dev/sda

Geschwindigkeit einschränken

• echo "8:0 1048576" > /sys/fs/cgroup/blkio/mygroup/blkio.throttle.write_bps_device

Erneutes checken

• cgget -g blkio /mygroup | grep blkio.throttle.write_bps_device

blkio.throttle.write_bps_device: 8:0 1048576

Ohne Einschränkung

• dd if=/dev/zero of=/tmp/test count=50 bs=100M

50+0 records in
50+0 records out
5242880000 bytes (5.2 GB, 4.9 GiB) copied, 23.0043 s, 228 MB/s

Mit Einschränkung(Funktioniert nicht wie gewünscht)

• cgexec -g blkio:/mygroup dd if=/dev/zero of=/tmp/test count=50 bs=100M