Transcript Testing High Performance Tape Drives HEPiX FALL 2005 Data Services Section Hugo Caçote @ HEPiX Fall 2005

Testing High Performance Tape Drives
HEPiX FALL 2005
Data Services Section
Hugo Caçote @ HEPiX Fall 2005
Motivation
LHC
~15 Petabytes/year
Hugo Caçote @ HEPiX Fall 2005
Current Model
DATA
DATA
RFIO
DATA
DATA
CASTOR
HSM
DATA
DATA
Hugo Caçote @ HEPiX Fall 2005
Devices Tested
IBM 3592JA Tape Drive
IBM 3584 Library
+
+
300 GB / 60 GB
40 MB/sec
Future Generation Tape Drives >100 MB/s
117 carts
12 drives
Testing in 2006
HP LT0-3
+
STK SL8500
+
400 GB
1,448 carts
64 drives
80 MB/sec
Hugo Caçote @ HEPiX Fall 2005
Test Infrastructure
Tape Server
Tape Library
Fiber
Fiber Channel HBA
Tape Drive
Hugo Caçote @ HEPiX Fall 2005
Functionality Tests
• Go through the set of commands available on the SCSI standard
Check returned information, timing, command acceptance
SCSI 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
Hugo Caçote @ HEPiX Fall 2005
Functionality Tests
fibre channel analyzer for
verifying SCSI commands
Hugo Caçote @ HEPiX Fall 2005
Test Scenarios
Linux tape driver and cernTapeTestUtil (interactive/command line mode)
Hugo Caçote @ HEPiX Fall 2005
Analysis of Results
Hugo Caçote @ HEPiX Fall 2005
Mechanical Tests
IBM 3592:
Over 125,000 mount/dismount cycles performed, no errors
Test mechanical reliability of drive / media: some cartridges now
mounted > 4000 times, no errors
Random file reads on selected tapes and media:
superseded by CASTOR operation in data challenges
HP LTO-3:
Over 125,000 mount/dismount cycles performed, no errors
Test mechanical reliability of drive / media: some cartridges now
mounted > 5000 times, no errors
Hugo Caçote @ HEPiX Fall 2005
Performance Tests
- Use of native Linux Commands (mt/dd) for data transfers :
•
•
•
•
•
read / write
compression / no compression
blocksize
filesize
position “labeled” files
Hugo Caçote @ HEPiX Fall 2005
Performance
LTO-3 Data Transfer Rate
Write no compression
MBytes/s
MBytes/s with blocksize, L30099
80
70
60
50
40
30
20
10
0
1
4
16
64
25
6
2
0
1
4
Blocks (K)
Hugo Caçote @ HEPiX Fall 2005
Performance
LTO-3 Data Transfer Rate
Read no compression
MBytes/s
MBytes/s with blocksize, L30100
80
70
60
50
40
30
20
10
0
1
4
16
64
6
25
4
2
10
Blocks (K)
Hugo Caçote @ HEPiX Fall 2005
Performance
LTO-3 Locate File Timing
LTO-3 Locate Record Timing
Skipping 40 MB files
180
Skipping 512 MB steps
160
140
140
120
120
Seconds
Seconds
100
100
Skip
80
Skip
80
Rewind
Rewind
6060
4040
2020
00
1 11 21 31 41 51 61 71 81 91 101 111 121 131 141 151 161 171 181 191 201 211 221 231 241 251 261 271
1 37 73 109 145 181 217 253 289 325 361 397 433 469 505 541 577 613 649 685 721 757
Groups of 33 labelled files
Skips
Hugo Caçote @ HEPiX Fall 2005
ANSI Labels
80 Bytes
80 Bytes
80 Bytes
Header 1
Header 2
Header 3
0-? Bytes
Tapemark
Data
Tapemark
80 Bytes
80 Bytes
80 Bytes
Trailer 1
Trailer 2
Trailer 3
Headers
Filename, block size, HSM version, time of writing …
Trailers
Number of blocks, non standard data …
Tapemark
Sync
Tapemark
Special records on tape used by the drive , immediate bit =0/1
Flush buffer
Hugo Caçote @ HEPiX Fall 2005
Sync
Labels vs Performance
Average Effective Write Data Transfer HP LTO-3
70
Minimum
over head
Data Transfer MBytes/s
60
50
40
Imm=1Tpmrk=3 Sync=1
Imm=0 Tpmrk=3 Sync=1
Imm=0 Tpmrk=1 Sync=1
30
Imm=0 Tpmrk=0 Sync=1
Imm=0 Tpmrk=0 Sync=0
Maximum
over head
20
10
0
0
500
1000
1500
2000
File Size/MBytes
Hugo Caçote @ HEPiX Fall 2005
Labels vs Performance
Average Effective Write Data Transfer HP LTO-3 vs IBM 3592JA
70
Data Transfer MBytes/s
HP-LTO3
60
Imm=1Tpmrk=3 Sync=1 LTO3
Imm=0 Tpmrk=3 Sync=1 LTO3
50
Imm=0 Tpmrk=1 Sync=1 LTO3
Imm=0 Tpmrk=0 Sync=1 LTO3
Imm=0 Tpmrk=0 Sync=0 LTO3
Imm=1Tprmk=3 Sync=1 3592
40
Imm=0 Tpmrk=3 Sync=1 3592
Imm=0 Tpmrk=1 Sync=1 3592
Imm=0 Tpmrk=0 Sync=1 3592
Imm=0 Tpmrk=0 Sync=0 3592
30
20
IBM 3592JA
10
0
0
200
400
600
800
1000
1200
1400
1600
1800
2000
File Size/MBytes
Hugo Caçote @ HEPiX Fall 2005
Labels vs Performance
Average Effective Write Data Transfer HP LTO-3 vs IBM 3592JA
70
60
Imm=1Tpmrk=3 Sync=1 LTO3
Imm=0 Tpmrk=3 Sync=1 LTO3
Imm=0 Tpmrk=1 Sync=1 LTO3
Imm=0 Tpmrk=0 Sync=1 LTO3
Imm=0 Tpmrk=0 Sync=0 LTO3
IBM 3592
small files
40
Imm=1 Tpmrk=3 Sync=1 3592
Imm=0 Tpmrk=3 Sync=1 3592
Imm=0 Tpmrk=1 Sync=1 3592
Imm=0 Tpmrk=0 Sync=1 3592
30
20
Imm=0 Tpmrk=0 Sync=0 3592
10
2024
1000
700
400
97
100
94
91
88
85
82
79
76
73
70
67
64
61
58
55
52
49
46
43
40
37
34
31
28
25
22
19
16
13
7
10
4
1
0
0.25
Data Transfer MBytes/s
50
File Size/MBytes
Hugo Caçote @ HEPiX Fall 2005
HSM Integration
Functionality + Mechanical + Performance
OK
Drive integration in HSM system
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
Hugo Caçote @ HEPiX Fall 2005
Operations
IBM 3592/HP LT0-3:
SNMP Agent :
Error Counters
Tape Alerts
Drive and Media: number mounts/Loads/…
IBM 3592:
Statistical Analysis and Reporting System :
bit 62: SARS Drive Relative Quality
X'00' is unknown, best X'01' -> worst X'FF‘
Request Sense
bit 63 SARS Media Relative Quality
X'00' is unknown, best X'01' -> worst X'FF'
No Vendor:
drives
Perfect tool for monitoring all type of drives and for a large number of
Hugo Caçote @ HEPiX Fall 2005
More Tests
RFIO
CASTOR
HSM
??
SAN
$$
Hugo Caçote @ HEPiX Fall 2005