分析在 Ceph 上运行的 OpenStack 虚拟机写入和读取模式

分析所有虚拟机 IO 模式。

在您的 ceph.conf 中添加以下内容

[client]
log file = /var/log/qemu/qemu-guest.$pid.log
debug rbd = 20

日志文件的路径必须可由 QEMU 写入。 日志显示提交的 IO 的偏移量和长度。

一些示例

• DD 一次 4K：dd if=/dev/zero of=/dev/vdb bs=4k count=1 conv=fsync

librbd: aio_write 0x7f2b01690ab0 off = 0 len = 4096 buf = 0x7f2a981b2000

• DD 10 次 1M：dd if=/dev/zero of=/dev/vdb bs=1M count=10 conv=fsync

librbd: aio_write 0x7f2b01690ab0 off = 0 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 1048576 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 2097152 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 3145728 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 4194304 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 5242880 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 6291456 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 7340032 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 8388608 len = 1048576 buf = 0x7f2a98338200
librbd: aio_write 0x7f2b01690ab0 off = 9437184 len = 1048576 buf = 0x7f2a98338200

请注意，这些数据中的大部分也通过管理套接字聚合，该套接字也可以为在 Ceph 上运行的虚拟机设置。