orchestrated in the cloud • Curve can backup / sync data to slave cloud • When master cloud failure happens, Database service can move to the slave cloudData apps(middleware/bigdata/ai) • CurveFS can

maximum number of mounts. # Currently (2014) it must be typed exactly as shown # (with a single space before and after the equals sign). #mount_max = 100 # man fuse user_allow_other Allow non-root wants to enable. * * libfuse attempts to initialize this field with * reasonable default values before calling the init() handler. */ unsigned want; /** * Maximum number of pending "background" test # owner: root # group: root user::rw- group::r-- other::r-- # wanghai01w© XXX Page 23 of 33 # before set wanghai01@pubbeta2-curve5:/tmp$ echo "hello" >> acl.test -bash: acl.test: Permission denied #

#define O_TRUNC 00001000 #define O_APPEND 00002000 #define O_NONBLOCK 00004000 #define O_SYNC 00010000(before linux 2.6.33) 04010000(after linux 2.6.33) #define O_DSYNC 00010000(after linux 2.6.33) #define FASYNC permitted. If the -o default_permissions mount option is given, this check is already done by the kernel before calling open() and may thus be omitted by the filesystem. When writeback caching is enabled, the

The Annual Failure Rate of disks is AFR, and the average running Time of disks is MTBF (Mean Time Before Failure). 𝐴𝐹𝑅 = 1 𝑀𝑇𝐵𝐹/（24 ∗ 365） ∗ 100 In CurveBS, the data on one disk is distributed

CurveBS I/O processing flow Before introducing IO processing flow, we first describe the overall architecture, data organization and topology structure of CURVE. CurveBS uses the central