1. Tape Drive Testing
IBM 3592

2. IBM 3592 tape drive Maximum native data rate of 40 MB/s
60GB (not for us) and 300 GB IBM 3592 cartridge
8 meters/s high-speed search
Compatible with IBM tape library, not STK tape library (Powderhorn)
1Gps/2Gps fibre channel connection
3592 tape drive
3584 library

3. Initial test infrastructure (now 8 ‘mid-range` servers)
Tape Server
IBM 3584 Tape Library
Fiber
Qlogic Fiber Channel Bus Adapter
IBM 3592 Tape Drive

4. Over 125,000 mount/dismount cycles performed, no errors
‘Mechanical` tests
Over 125,000 mount/dismount cycles performed, no errors
Test mechanical reliability of drive / media: some cartridges now mounted > 4000 times, no errors
Perform random file reads on selected tapes and media: superseded by CASTOR/ALICE MDC6 operation

5. Performance tests General characteristics
Drive mount (from slot) 3.2 s
Time to access VOL s
Rewind s
Unload s
Dismount (to slot) s
Write very small ‘labelled file’ 0.2s
CM chip, RF I/O, 4096 bytes, part of cartridge
512 tracks in 64 sets of 8
8 m/s high speed search
20,000 load/unload cycle lifetime for cartridge
300 full file passes lifetime for cartridge
Measurements made over 88 cartridges in the 3584

6. `Performance` tests (without CASTOR)
Read and write to tape
Use UNIX commands mt, dd only
Similar tests are carried out on all new types of drive to be used at CERN to measure…
Capacity of cartridge and blocksize, 1-256K
Capacity of cartridge and filesize
Write datarate with blocksize 1-256K
Write datarate with blocksize 1-17K
Write datarate with very small blocksize bytes
Read datarate with blocksize 1-256K
Reproducibility of maximum capacity, filling a single cartridge
Variation in maximum capacity, filling different cartridges
Labelled files, 'position to file' and rewind timings
Blocks, 'position to block' and rewind timings
Apparent sizes of small labelled files, from rewind timings
Time to create small labelled files
Compression write datarate with blocksize 1-256K
Compression read datarate with blocksize 1-256K
Compression write datarate with filesize
Verification of legal FC command execution
…..and so on and so on…….

7. `Performance` tests (using CASTOR)
Verify the functioning of the CASTOR and CASTOR related functions:
tape_up tape unit standard testing for production utility
tplabel tape labelling utility
dumptape tape dumping (scanning) utility
stagein tape reading utility
stagewrt tape writing utility
repack move CASTOR file from tape and reclaim utilities

8. `Performance` tests: some typical examples..
No compression, 1K=1024, 1M=
Data transfer rate (write)

9. `Performance` tests: some typical examples..
Compressed data transfer rate (write)
Use compression, 1K=1024, 1M=
dd if=/dev/zero ibs=256k of=/dev/nst0 obs=256k count=n

10. `Performance` tests: some typical examples..
‘Labelled’ file position/rewind times
‘user’ files on tape, each ~25 MB (100 blocks of 256K), simulated labels
The 64 serpentine track sets (32 ‘out’, 32 ‘back) show clearly!
Command mt -f /dev/nst0 fsf n
Command mt -f /dev/nst0 rewind

11. Check returned information, timing, command acceptance
Functionality Tests
Go through the set of commands available on the SCSI standard
Check returned information, timing, command acceptance
SCSI 3 COMMANDS:
Change Definition, Compare, Copy, Copy and Verify, Display Message, Erase, Format Medium, Inquiry, Load/Unload, Locate , Log Select, Log Sense, Mode Select (6), Mode Select (10), Mode Sense (6), Mode Sense (10), Persistent Reserve In, Persistent Reserve Out, Prevent/Allow Medium Removal, Read, Read Attribute, Read Block Limits, Read Buffer, Read Position, Read Reverse, Receive Diagnostic Results, Recover Buffered Data, Release Unit (6), Release Unit (10), Report Density Support LUNs, Request Sense Unit (6), Reserve Unit (10), Rewind, Send Diagnostic, Set Capacity, Space, Test Unit Ready, Verify, Write, Write Attribute, Write Buffer, Write Filemarks
IBM 3592 TESTED COMMANDS
Display Message, Erase, Inquiry, Load/Unload, Locate , Log Select, Log Sense, Mode Select (10), Mode Sense (10), Persistent Reserve In, Persistent Reserve Out, Prevent/Allow Medium Removal, Read, Read Block Limits, Read Buffer, Read Position, Receive Diagnostic Results, Recover Buffered Data, Release Unit (6), Report Density Support, Report LUNs, Request Sense Unit (6), Reserve Unit (6), Rewind, Send Diagnostic, Space, Test Unit Ready, Write, Write Buffer, Write Filemarks OK

12. Test Infrastructure

13. Test Scenarios
1) IBM tape driver and IBMtapeutil (interactive/command line mode)
2) Linux tape driver and cernTapeTestUtil (interactive/command line mode)

14. Analysis of Results

15. Conclusions IBM 3592 Tape Drive SCSI commands OK
cernTapeTestUtil more than a test tool for tape drives; also a diagnostics tool .... provides access to vital information on tape drive and media statistics and status
cernTapeTestUtil works on STK 9840, STK 9940, HP LT02 as well as 3592 and will be used on any new equipment that will arrive to be tested
Use of a SCSI/fibre channel analyzer permits a precise logging of results and this can be used for all our drives