Linux io-stack-diagram v1.0

Linux io-stack-diagram v1.0

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  Applications (Processes) direct I/O (O_DIRECT) VFS Page Cache nvme hookedin Device Drivers (hook in similar like stacked devices like mdraid/device mapper do) iomemory-vsl with module option LVM Block I/O Layer optional stackable devices on top of “normal” block devices – work on bios mdraid device mapper drbd ... I/O Scheduler maps bios to requests deadlinecfq noop request-based device mapper targets dm-multipath SCSI mid layer virtio_blk iomemory-vsl Physical devices HDD SSD DVD drive Micron PCIe Card Fusion-io PCIe Card LSI RAID Adaptec RAID Qlogic HBA Emulex HBA ... malloc read(2) write(2) open(2) stat(2) chmod(2) ... BIOs (Block I/O) sysfs (transport attributes) /dev/vd* SCSI upper layer /dev/sda .../dev/sdb /dev/fio* SCSI low layer megaraid sas aacraid qla2xxx ... libata ahci ata_piix ... lpfc Transport Classes scsi_transport_fc scsi_transport_sas scsi_transport_... /dev/fio* /dev/nvme#n# mtip32xx /dev/rssd* The Linux I/O Stack Diagram (version 1.0, 2012-06-20) http://www.thomas-krenn.com/en/oss/linux-io-stack-diagram.html Created by Werner Fischer and Georg Schönberger License: CC-BY-SA 3.0, see http://creativecommons.org/licenses/by-sa/3.0/ block based FS ext2 ext3 btrfs ext4 xfs ifs iso9660 ... NFS coda Network FS gfs ocfs smbfs ... pseudo FS special purpose FSproc sysfs futexfs usbfs ... tmpfs ramfs devtmpfs pipefs network nvme device The Linux I/O Stack Diagram version 1.0, 2012-06-20 outlines the Linux I/O stack as of Kernel version 3.3 mmap (anonymous pages) stackable iscsi_tcp network