1. Files This distribution contains the following files: a) README.txt: this file b) *.tgz: I/O trace files, described below c) md5_check.md5: output of md5sum for tgz files 2. I/O trace files There are 216 I/O traces from a warehouse (also called a failure domain) of a production cloud block storage system (CBS). The traces are I/O requests from 5584 cloud virtual volumes (CVVs) for ten days (from Oct. 1st to Oct. 10th, 2018). The I/O requests from the CVVs are mapped and redirected to a storage cluster consists of 40 storage nodes (i.e., disks). More information about the CBS architecture is available from the ATC '20 paper titled "OSCA: An Online-Model Based Cache Allocation Scheme in Cloud Block Storage Systems". Each trace file is named as .tgz. The date format consists of year(4 char.), month(2 char.), day(2 char.), and hour(2 char.). Here is an example file name. 2018-10-01-01.tgz - year : 2018 - month : 10 (Oct.) - day : 1st - hour : 1 AM 3. I/O trace file format The files are compressed comma-separated text files leveraging "tar" command. The fields in the files are: Timestamp,Offset,Size,IOType,VolumeID - Timestamp is the time the I/O was issued. The timestamp is given as a Unix time (seconds since 1/1/1970). - Offset is the starting offset of the I/O in sectors from the start of the logical virtual volume. 1 sector = 512 bytes - Size is the transfer size of the I/O request in sectors. - IOType is "Read(0)", "Write(1)". - VolumeID is the ID number of a CVV. 4. Some suggestions on the use of the traces In addition to using these traces to examine the issues discussed in the ATC '20 paper, they can be used to analyze: (1) the CBS access patterns of CVVs by dividing traces for each CVV using the VolumeID. (2) the architecture optimization of CBS by simulating the mapping of I/O requests to storage nodes. 5. Attribution. Please cite the publication of the ATC '20 paper mentioned above as a reference in any published work using these traces.