Overview of DLSS Workshop Don Petravick FNAL Office of Science Data Management Workshop

D. Petravick -- Office of Science Data Management Workshop DLSS What was it? DLSS Disk in Large Scale Storage Systems Feb 19-20 Hosted by NASA Goddard http://www.westoverconferences.com/dvt/dvt_agenda.htm Agenda Government Requirements, Cost, Performance, Reliability, File Systems, Security, Legal Requirements. I’ll present to my own schema. 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

Government Requirements Evident difference between defense type systems and scientific systems. Defense type systems stringent and increasing security requirements, kernel level file protections, etc. Science more able to exploit middleware approaches file systems implemented in middleware. Some frustration with the nature of the POSIX file interface. 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

D. Petravick -- Office of Science Data Management Workshop Technology Talk by STK about tape. (B. Raymond) Disk Discriminate by market, not by interface “personal”, Enterprise. Disk qualities differ depending on market Talk by D. Anderson (Seagate) about interfaces and features in disks. “Disk becomes tape” 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

It’s not Just the Interface! A drive, is a drive, is a drive. Or is it ? Cost Reliability Scalability Performance Data Integrity Desktop 7,200 rpm ATA/SATA Power Consumption Enterprise 15,000 rpm SCSI/FC System Architecture What’s important to the Application ? 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

PS Drive RV Operating Range RVI (max rms) Cabinet Compare w/Cheetah 10K.6 - Seek Data Only 5 10 15 20 25 30 35 40 45 50 1 2 3 4 6 7 8 9 11 12 13 14 16 17 18 19 21 22 23 24 26 27 28 29 31 32 33 Cabinet/Vendor rads/sec (rms) --- Bars represent range of min to max values Abnormal Range 37 Rad/s**2 Normal Range 21 Rad/s**2 Average of all samples for this cabinet PS Drive RV Operating Range 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

D. Petravick -- Office of Science Data Management Workshop Application -- Backup Current: Large permanent store people and backup community share tape as a media Talks by COPAN, Kai Li (Princeton) Backup community is interested in disk. Accelerated backup Diminishes the role of removable media 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

Application Permanent Store High Energy Physics sites currently have ~2PB. Ingest rate to permanent stores are ~100 TB/month Permanent stores are not necessarily archives. Loss rate per replication About 1/million 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

Large Permanent Stores Currently implemented on tape. Requirements beyond naïve cost, capacity Security requirements, accident Full understanding of errors in the systems Issue of continuously ingesting materials. Archival quality of personal disk Not only Disk BER, block-level logic errors FNAL commodity disk/ Linux buffering experience Archival disk format should be Robust Standard 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

Application -- Buffering secure community v.s. high perf/science community. Commodity v.s. enterprise approach Middleware v.s. kernal Questions of if posix access semantics are sufficient. Extensions, if any were not clear 12/31/2018 D. Petravick -- Office of Science Data Management Workshop

Tentative, Personal Gap Analysis from DLSS. Disks as a technology Big Science buffers are not a market center for personal disks Analogous to good cluster building? In the limit COTS !=> JIT? Access Evident need to understand if POSIX semantics are sufficient. Extensions, common basis for them were not clear Could be explored Permanent Store, as we know it. There is Potential for fiducially permanent store The kind a program manager would trust Work needed, not explicitly supported in the market today. Backup Is increasingly specialized. 12/31/2018 D. Petravick -- Office of Science Data Management Workshop