title: ÐÐ¾Ð²ÑÑÐµÐ½Ð¸Ðµ Ð¼Ð°ÑÑÑÐ°Ð±Ð¸ÑÑÐµÐ¼Ð¾ÑÑÐ¸ ÑÐ¸ÑÑÐµÐ¼Ñ Ñ ÑÐ°Ð½ÐµÐ½Ð¸Ñ Ð´Ð°Ð½Ð½ÑÑ Ð¿ÑÑÐµÐ¼ ÑÐµÐ°Ð»Ð¸Ð·Ð°ÑÐ¸Ð¸ ÑÑÐµÐºÐ° Ð¿ÑÐ¾ÑÐ¾ÐºÐ¾Ð»Ð¾Ð² SCSI Ð² Ð¿ÑÐ¾ÑÑÑÐ°Ð½ÑÑÐ²Ðµ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ
title: Ð²ÑÐ¿ÑÑÐºÐ½Ð°Ñ ÐºÐ²Ð°Ð»Ð¸ÑÐ¸ÐºÐ°ÑÐ¸Ð¾Ð½Ð½Ð°Ñ ÑÐ°Ð±Ð¾ÑÐ° Ð¼Ð°Ð³Ð¸ÑÑÑÐ°
titleType: Subtitle
title: Increasing storage scalability by implementing the SCSI protocol stack in user-space
Creators: name: ÐÐ¾Ð¿ÑÐµÐ², ÐÐµÐ½Ð¸Ñ
Publisher: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑÐ½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾
Year: 2020
Subjects: ÑÐ¸ÑÑÐµÐ¼Ð° Ñ ÑÐ°Ð½ÐµÐ½Ð¸Ñ Ð´Ð°Ð½Ð½ÑÑ
Ð¼Ð°ÑÑÑÐ°Ð±Ð¸ÑÑÐµÐ¼Ð¾ÑÑÑ
scsi
iscsi
linux
scst
Ð¿ÑÐ¾ÑÑÑÐ°Ð½ÑÑÐ²Ð¾ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ
storage system
scalability
user-space

description: Ð¢ÐµÐ¼Ð° Ð²ÑÐ¿ÑÑÐºÐ½Ð¾Ð¹ ÐºÐ²Ð°Ð»Ð¸ÑÐ¸ÐºÐ°ÑÐ¸Ð¾Ð½Ð½Ð¾Ð¹ ÑÐ°Ð±Ð¾ÑÑ: Â«ÐÐ¾Ð²ÑÑÐµÐ½Ð¸Ðµ Ð¼Ð°ÑÑÑÐ°Ð±Ð¸ÑÑÐµÐ¼Ð¾ÑÑÐ¸ ÑÐ¸ÑÑÐµÐ¼Ñ ÑÑÐ°Ð½ÐµÐ½Ð¸Ñ Ð´Ð°Ð½Ð½ÑÑ Ð¿ÑÑÐµÐ¼ ÑÐµÐ°Ð»Ð¸Ð·Ð°ÑÐ¸Ð¸ ÑÑÐµÐºÐ° Ð¿ÑÐ¾ÑÐ¾ÐºÐ¾Ð»Ð¾Ð² SCSI Ð² Ð¿ÑÐ¾ÑÑÑÐ°Ð½ÑÑÐ²Ðµ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»ÑÂ». 
Ð Ð°Ð±Ð¾ÑÐ° Ð¿Ð¾ÑÐ²ÑÑÐµÐ½Ð° Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ Ð²Ð»Ð¸ÑÐ½Ð¸Ñ Ð¸ÑÐ¿Ð¾Ð»Ð½ÐµÐ½Ð¸Ñ Ð»Ð¾Ð³Ð¸ÐºÐ¸ ÑÑÐ°Ð½Ð´Ð°ÑÑÐ° SCSI Ð² Ð¿ÑÐ¾ÑÑÑÐ°Ð½ÑÑÐ²Ðµ ÑÐ´ÑÐ° Linux Ð½Ð° Ð¼Ð°ÑÑÑÐ°Ð±Ð¸ÑÑÐµÐ¼Ð¾ÑÑÑ ÐÐ ÑÐ¸ÑÑÐµÐ¼Ñ ÑÑÐ°Ð½ÐµÐ½Ð¸Ñ Ð´Ð°Ð½Ð½ÑÑ, Ð° ÑÐ°ÐºÐ¶Ðµ Ð¿ÑÐ¾ÐµÐºÑÐ¸ÑÐ¾Ð²Ð°Ð½Ð¸Ñ ÑÐµÑÐµÐ½Ð¸Ñ, Ð¿Ð¾Ð·Ð²Ð¾Ð»ÑÑÑÐµÐ³Ð¾ ÑÐ½Ð¸Ð·Ð¸ÑÑ Ð½Ð°ÐºÐ»Ð°Ð´Ð½ÑÐµ ÑÐ°ÑÑÐ¾Ð´Ñ.
Ð Ð°Ð±Ð¾ÑÐ° Ð¿ÑÐ¾Ð²Ð¾Ð´Ð¸Ð»Ð°ÑÑ Ð½Ð° Ð¾ÑÐ½Ð¾Ð²Ðµ ÑÑÑÐµÑÑÐ²ÑÑÑÐµÐ³Ð¾ ÐºÐ¾Ð¼Ð¼ÐµÑÑÐµÑÐºÐ¾Ð³Ð¾ Ð¿ÑÐ¾Ð´ÑÐºÑÐ°. ÐÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ðµ Ð¸ÑÑÐ¾Ð´Ð½Ð¾Ð³Ð¾ ÑÐµÑÐµÐ½Ð¸Ñ Ð¸ ÑÐºÑÐ¿ÐµÑÐ¸Ð¼ÐµÐ½ÑÑ Ð¿Ð¾ÐºÐ°Ð·Ð°Ð»Ð¸, ÑÑÐ¾ Ð¿Ð¾Ð»Ð½Ð¾ÑÐµÐ½Ð½Ð¾Ðµ Ð¸ÑÐ¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°Ð½Ð¸Ðµ Ð´ÑÐ°Ð¹Ð²ÐµÑÐ°-ÑÐµÐ°Ð»Ð¸Ð·Ð°ÑÐ¸Ð¸ SCSI, SCST, Ð¾ÐºÐ°Ð·ÑÐ²Ð°ÐµÑ Ð¿Ð°Ð³ÑÐ±Ð½Ð¾Ðµ Ð²Ð»Ð¸ÑÐ½Ð¸Ðµ Ð½Ð° Ð¼Ð°ÑÑÑÐ°Ð±Ð¸ÑÑÐµÐ¼Ð¾ÑÑÑ Ð¿ÑÐ¾Ð³ÑÐ°Ð¼Ð¼Ð½Ð¾Ð³Ð¾ Ð¾Ð±ÐµÑÐ¿ÐµÑÐµÐ½Ð¸Ñ ÑÐ¸ÑÑÐµÐ¼Ñ ÑÑÐ°Ð½ÐµÐ½Ð¸Ñ Ð´Ð°Ð½Ð½ÑÑ Ð²ÑÐ»ÐµÐ´ÑÑÐ²Ð¸Ðµ Ð½ÐµÑÑÑÐµÐºÑÐ¸Ð²Ð½Ð¾ÑÑÐ¸ Ð¿ÑÐ¸Ð¼ÐµÐ½ÑÐµÐ¼ÑÑ Ð°Ð»Ð³Ð¾ÑÐ¸ÑÐ¼Ð¾Ð² Ð¸ Ð½Ð°ÐºÐ»Ð°Ð´Ð½ÑÑ ÑÐ°ÑÑÐ¾Ð´Ð¾Ð² Ð¸ÑÐ¿Ð¾Ð»Ð½ÐµÐ½Ð¸Ñ Ð»Ð¾Ð³Ð¸ÐºÐ¸ Ð² ÑÐ´ÑÐµ.
Ð¡ ÑÐµÐ»ÑÑ Ð¿Ð¾Ð²ÑÑÐµÐ½Ð¸Ñ Ð¼Ð°ÑÑÑÐ°Ð±Ð¸ÑÑÐµÐ¼Ð¾ÑÑÐ¸ ÑÐ¸ÑÑÐµÐ¼Ñ Ð±ÑÐ»Ð¾ ÑÐ¿ÑÐ¾ÐµÐºÑÐ¸ÑÐ¾Ð²Ð°Ð½Ð¾ Ð¸ ÑÐµÐ°Ð»Ð¸Ð·Ð¾Ð²Ð°Ð½Ð¾ ÑÐµÑÐµÐ½Ð¸Ðµ, Ð·Ð°ÐºÐ»ÑÑÐ°ÑÑÐµÐµÑÑ Ð² Ð¿ÐµÑÐµÐ½Ð¾ÑÐµ Ð¸ÑÐ¿Ð¾Ð»Ð½ÐµÐ½Ð¸Ñ Ð±Ð¾Ð»ÑÑÐµÐ¹ ÑÐ°ÑÑÐ¸ Ð»Ð¾Ð³Ð¸ÐºÐ¸ SCSI Ð² Ð¿ÑÐ¾ÑÑÑÐ°Ð½ÑÑÐ²Ð¾ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ. ÐÑÐµÐ´ÑÑÐ°Ð²Ð»ÐµÐ½Ð½ÑÐ¹ Ð² ÑÐ°Ð±Ð¾ÑÐµ Ð¿Ð¾Ð´ÑÐ¾Ð´ Ð¾ÑÐ½Ð¾Ð²Ð°Ð½ Ð½Ð° Ð¸ÑÐ¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°Ð½Ð¸Ð¸ Ð´ÑÐ°Ð¹Ð²ÐµÑÐ° SCST Ð² ÐºÐ°ÑÐµÑÑÐ²Ðµ ÑÑÐ½Ð½ÐµÐ»Ñ Ð´Ð»Ñ Ð¿ÐµÑÐµÐ´Ð°ÑÐ¸ ÑÑÐ°ÑÐ¸ÐºÐ° Ð¾Ñ ÑÐ¾ÑÑÐ¾Ð² Ð² Ð¿ÑÐ¾ÑÑÑÐ°Ð½ÑÑÐ²Ð¾ Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ, Ð³Ð´Ðµ Ð±ÑÐ»Ð° ÑÐµÐ°Ð»Ð¸Ð·Ð¾Ð²Ð°Ð½Ð° Ð»Ð¾Ð³Ð¸ÐºÐ° ÐºÐ¾Ð½ÑÐ¸Ð³ÑÑÐ¸ÑÐ¾Ð²Ð°Ð½Ð¸Ñ Ð½ÐµÐ¾Ð±ÑÐ¾Ð´Ð¸Ð¼ÑÑ ÑÑÑÐ½Ð¾ÑÑÐµÐ¹ Ð¸ Ð¾Ð±ÑÐ°Ð±Ð¾ÑÑÐ¸ÐºÐ¸ Ð·Ð°Ð²Ð¸ÑÐ¸Ð¼ÑÑ SCSI-ÐºÐ¾Ð¼Ð°Ð½Ð´. Ð ÐµÐ·ÑÐ»ÑÑÐ°ÑÑ Ð°Ð¿ÑÐ¾Ð±Ð°ÑÐ¸Ð¸ Ð½Ð¾Ð²Ð¾Ð³Ð¾ ÑÐµÑÐµÐ½Ð¸Ñ Ð¿Ð¾ÐºÐ°Ð·Ð°Ð»Ð¸ Ð²ÑÑÐ¾ÐºÐ¸Ð¹ Ð¿Ð¾ÑÐµÐ½ÑÐ¸Ð°Ð» ÐµÐ³Ð¾ Ð²Ð½ÐµÐ´ÑÐµÐ½Ð¸Ñ Ð² ÑÑÑÐµÑÑÐ²ÑÑÑÐ¸Ð¹ Ð¿ÑÐ¾Ð´ÑÐºÑ.
description: The subject of the graduate work is âIncreasing storage scalability by implementing the SCSI protocol stack in user-spaceâ.
The given work is devoted to estimation of the storage scalability overhead which can potentially arise from an execution of the SCSI protocol logic in the Linux kernel-space, as well as to designing a solution to reduce these overhead costs.
The work was carried out based on the existing commercial storage system. The study of the initial solution and the experiments proved that the full use of the SCST kernel driver being an implementation of the SCSI target subsystem causes a significant scalability degradation due to an inefficiency of the applied algorithms and an overhead of the in-kernel execution.
A solution based on transferring the execution of most of the SCSI logic to user-space was designed in order to increase the storage scalability. The approach presented in this work uses SCST as a tunnel for transmitting a host traffic to the storage software. In the same time, the logic for configuring SCSI entities and handling dependent protocol commands was optimized and re-implemented in user-space. The final testing and analysis of the new solution proved a high potential for its integration into the existing product.