/foo/bar in CurveBS 2. The address space of the block device /dev/sda maps to chunks of file in the system. For example, chunk1 corresponds to the address space of 0 to 4MB in /dev/sda, and chunk2 corresponds 1. A CopySet, as the basic unit of a consistent replication group, contains Consensus Module and Log Module. 2. The State Machine corresponds to the chunk in the CurveBS, and it applies the operations the CurveBS Client has been optimized to decouple the application from libcurve and add a NEBD module to join the two. l Nebdclient: Forward the requests from QEMU and curve-NBD to the specified

parameter. If the number of pending * background requests exceeds this number, the FUSE kernel module will * mark the filesystem as "congested". This instructs the kernel to * expect that queued variable can be used to inform the * kernel about the timestamp granularity supported by the file-system.© XXX Page 13 of 33 * The value should be power of 10. The default is 1, i.e. full * nano-second rlim_max=256*1024}) = 0 lstat("acl.test", {st_mode=S_IFREG|0674, st_size=6, ...}) = 0 getxattr("acl.test", "system.posix_acl_access", "\2\0\0\0\1\0\6\0\377\377\377\377\2\0\6\0\3362\0\0\4\0\4\0\377\377\377\377\20

replicas of data. If one replica fails, the system can read and write data successfully on the other two replicas. When two copies fail at the same time, the system cannot determine the failure reason because the actual situation of the system. Estimation of availability and reliability in the three- replicas case Assume that the total number of disks in Curve system is N, the number of replicas is

Easy operation and maintenance ○ High performance ● CEPH ○ Complex and Large amount of codes ○ system maintenance are difficult in corner cases ○ Performance requirements cannot be metAgenda Why develop flowOther performance optimizations RAFT protocol Zero data copy pre-created file poolCURVE file system File service middleware Upper-layer applications can access file data in storage pools through of Curve file systems ● System operation and maintenance ○ Further improve tools for installation/monitoring/maintenance ○ dashboard ● Cloud Native ○ Using CURVE file system in KubernetesCURVE community

kernel issues forget only after the release or releasedir * calls. * * Note that if a file system will be exported over NFS the * inodes lifetime must extend even beyond forget. See the * generation the lookup count for all inodes implicitly drops * to zero. It is not guaranteed that the file system will * receive corresponding forget messages for the affected© XXX Page 5 of 15 * inodes. nlookup); /** * Remove a file * * If the file's inode's lookup count is non-zero, the file * system is expected to postpone any removal of the inode * until the lookup count reaches zero (see description

High performance Cloud native Distributed storage system https://www.opencurve.io/Agenda • CurveBS Architecture • CurveBS Topology • CurveBS Data Organization • MetaData Server (MDS) • ChunkServer and expand CurveBS clusters • Use Curve Discover to discover resource changes and to collect the system’s runtime status to operatorCurveFS ArchitectureCurveFS Data OrganizationCurveFS File OrganizationCurveFS and expand CurveFS clusters • Use Curve Discover to discover resource changes and to collect the system’s runtime status to operatorthanksAbout RAFT

Curve integrate to Cloud NativeCurve intro • Curve is an distributed storage system • High performance • Easiser operation • Cloud native • Curve is composed of two parts • Curve Block Storage performance cloud native distributed block storage • Curve File System (CurveFS) • CurveFS: a high performance cloud native file system (Based on CurveBS / S3 compatible Storage)Operator capability Level

Curve High performance Cloud native Distributed storage system https://www.opencurve.io/Agenda • What is Curve • Use Cases • CurveBS • Key Features • Comparing to Ceph • CurveFS • Comparing is an distributed storage system • Components • Curve Block Storage (CurveBS) • CurveBS: a high performance cloud native distributed block storage • Curve File System (CurveFS) • CurveFS: a

010000000(since linux 2.6.39) #define O_TMPFILE 020000000|O_DIRECTORY #define O_NDELAY O_NONBLOCK(O_NDELAY是在System V的早期版本引入的，后改进为O_NONBLOCK) flags中必须access mode：O_RDONLY, O_WRONLY, O_RDWR其中之一；© XXX Page 4 of 23