{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,6,19]],"date-time":"2025-06-19T04:18:29Z","timestamp":1750306709309,"version":"3.41.0"},"reference-count":12,"publisher":"Association for Computing Machinery (ACM)","issue":"2","license":[{"start":{"date-parts":[[2014,9,15]],"date-time":"2014-09-15T00:00:00Z","timestamp":1410739200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["SIGARCH Comput. Archit. News"],"published-print":{"date-parts":[[2014,9,15]]},"abstract":"\n RAID5 disk arrays with rotated parities can tolerate single disk failures by reconstructing missing blocks on demand by XORing the contents of corresponding\n K<\/jats:italic>\n blocks on surviving disks by a\n K<\/jats:italic>\n -way\n Fork\/Join<\/jats:italic>\n (\n F\/J<\/jats:italic>\n ) request, which is considered completed after the\n K<\/jats:italic>\n disks are accessed. F\/J accesses in RAID5 are processed concurrently with interfering disk accesses. The mean response time of F\/J and independent\/interfering requests: R\n F\/J<\/jats:sup>\n \/\n K<\/jats:sub>\n and R\n Ind<\/jats:sup>\n and the mean delay from the completion of the first to the last F\/J task, known as task dispersion time: T\n disp<\/jats:sup>\n \/\n K<\/jats:sub>\n , are performance metrics of interest. Given R\n F\/J<\/jats:sup>\n \/\n K<\/jats:sub>\n > R\n Ind<\/jats:sup>\n with FCFS scheduling, it is desirable to equalize disk access times, but giving a higher nonpreemptive priority to disk accesses due to F\/J requests with respect to interfering disk accesses results in R\n Ind<\/jats:sup>\n & R\n F\/J<\/jats:sup>\n \/\n K<\/jats:sub>\n . We propose a continuum of conditional priority methods based on the fraction F of F\/J accesses completed with FCFS scheduling. F = \u221estands for FCFS and F = 0 stands for unconditional priorities. Simulation shows that F = 1\/8 with K = 8 yields R\n F\/J<\/jats:sup>\n \/\n K<\/jats:sub>\n \u2248 RInd for three distributions of disk requests and in the range of F\/J and independent disk requests considered. F can be varied adaptively based on measurement results to balance disk access times.\n <\/jats:p>","DOI":"10.1145\/2669594.2669598","type":"journal-article","created":{"date-parts":[[2014,9,17]],"date-time":"2014-09-17T14:22:25Z","timestamp":1410963745000},"page":"15-19","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Balancing disk access times in RAID5 disk arrays in degraded mode by conditionally prioritizing fork\/join requests"],"prefix":"10.1145","volume":"42","author":[{"given":"Alexander","family":"Thomasian","sequence":"first","affiliation":[{"name":"Thomasian and Associates, Pleasantville, NY"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bingxing","family":"Liu","sequence":"additional","affiliation":[{"name":"Thomasian and Associates, Pleasantville, NY"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuhui","family":"Deng","sequence":"additional","affiliation":[{"name":"Thomasian and Associates, Pleasantville, NY"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"320","published-online":{"date-parts":[[2014,9,15]]},"reference":[{"key":"e_1_2_1_1_1","doi-asserted-by":"publisher","DOI":"10.1145\/176979.176981"},{"volume-title":"Theory\/Computer Applications","year":"1975","author":"Kleinrock L.","key":"e_1_2_1_2_1"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1109\/12.2213"},{"key":"e_1_2_1_4_1","first-page":"111","volume-title":"Proc. 10th IEEE Int'l Conf. on Data Engineering","author":"Thomasian A.","year":"1994"},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.5555\/193201.194082"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1109\/71.595583"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1093\/comjnl\/bxh108"},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1109\/TC.2007.1041"},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/1629075.1629076"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1145\/2024716.2024719"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/2628913"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-642-40725-3_25"}],"container-title":["ACM SIGARCH Computer Architecture News"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2669594.2669598","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/2669594.2669598","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T07:19:15Z","timestamp":1750231155000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2669594.2669598"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,9,15]]},"references-count":12,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2014,9,15]]}},"alternative-id":["10.1145\/2669594.2669598"],"URL":"https:\/\/doi.org\/10.1145\/2669594.2669598","relation":{},"ISSN":["0163-5964"],"issn-type":[{"type":"print","value":"0163-5964"}],"subject":[],"published":{"date-parts":[[2014,9,15]]},"assertion":[{"value":"2014-09-15","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}