The original post: /r/datahoarder by /u/fgt67cam on 2024-05-24 19:13:55.
I recently purchased a used LTO-5 tape drive and some used tapes. LTO-5 has a rated capacity of 1.5TB (1.36TiB). When I've been writing data to these tapes (uncompressed) and they seem to cap at 1300 GiB which seems to be ~90GiB short. I write the tapes using the command:
tar cvf - /files-to-write 2> >(tee /Tape.log >&2) | mbuffer -m 14G -L -P 80 > /dev/st0
I recorded how much data was written to each different tape before I got the "tar: Exiting with failure status due to previous errors" message which usually means it has reached the end of the tape and can no longer write anything.
Tape 1: 1391776710636 bytes (1296 GiB)
Tape 2: 1424535198256 bytes (1326 GiB)
Tape 3: 1334993518029 bytes (1243 GiB)
Tape 4: 1383193282217 bytes (1292 GiB)
The tape drive I'm using is heavily used as well as the tapes. This is the sg_log for one of them:
HP Ultrium 5-SCSI I6CZ
Supported log pages [0x0]:
0x00 Supported log pages [sp]
0x02 Write error [we]
0x03 Read error [re]
0x0c Sequential access device [sad]
0x0d Temperature [temp]
0x11 DT Device status [dtds]
0x12 Tape alert response [tar]
0x13 Requested recovery [rr]
0x14 Device statistics [ds]
0x15 Service buffers information [sbi]
0x16 Tape diagnostic data [tdd]
0x17 Volume statistics [vs]
0x18 Protocol specific port [psp]
0x1b Data compression [dc]
0x2e Tape alert [ta]
0x30 Tape usage (lto-5, 6) [tu_]
0x31 Tape capacity (lto-5, 6) [tc_]
0x32 Data compression (lto-5) [dc_]
0x34 Read forward errors (lto-5) [rfe_]
0x35 DT Device Error (lto-5, 6) [dtde_]
0x3e Device Status (lto-5, 6) [ds_]
Write error counter page [0x2]
Errors corrected without substantial delay = 0
Errors corrected with possible delays = 0
Total rewrites or rereads = 0
Total errors corrected = 0
Total times correction algorithm processed = 0
Total bytes processed = 0
Total uncorrected errors = 0
Read error counter page [0x3]
Errors corrected without substantial delay = 0
Errors corrected with possible delays = 0
Total rewrites or rereads = 0
Total errors corrected = 0
Total times correction algorithm processed = 0
Total bytes processed = 0
Total uncorrected errors = 0
Sequential access device page (ssc-3)
Data bytes received with WRITE commands: 0 GB
Data bytes written to media by WRITE commands: 0 GB
Data bytes read from media by READ commands: 0 GB
Data bytes transferred by READ commands: 0 GB
Native capacity from BOP to EOD: 1527775 MB
Native capacity from BOP to EW of current partition: 1517690 MB
Minimum native capacity from EW to EOP of current partition: 12239 MB
Native capacity from BOP to current position: 17654 MB
Maximum native capacity in device object buffer: 206 MB
Cleaning action not required (or completed)
Temperature page [0xd]
Current temperature = 41 C
Reference temperature = <not available>
DT device status page (ssc-3, adc-3) [0x11]
Very high frequency data:
PAMR=0 HUI=0 MACC=1 CMPR=1 WRTP=0 CRQST=0 CRQRD=0 DINIT=1
INXTN=0 RAA=0 MPRSNT=1 MSTD=1 MTHRD=1 MOUNTED=1
DT device activity: No DT device activity
VS=0 TDDEC=0 EPP=0 ESR=0 RRQST=0 INTFC=0 TAFC=0
Very high frequency polling delay: 16 milliseconds
DT device ADC data encryption control status (hex only now):
00 00 00 00 00 00 00 00 00
Key management error data (hex only now):
00 00 00 00 00 00 00 00 00 00 00 00 00
Primary port 1 status:
non-SAS transport, in hex:
00 00 00 00 00 00 00 00 00 50 01 10 a0 01 4a a5 9c ........P....J..
10 50 01 10 a0 01 4a a5 9e P....J..
Primary port 2 status:
non-SAS transport, in hex:
00 3b 00 00 01 00 00 00 01 50 01 10 a0 01 4a a5 9d ;.......P....J..
10 50 01 10 a0 01 4a a5 9e P....J..
Primary port 3 status:
non-SAS transport, in hex:
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
10 00 00 00 00 00 00 00 00 ........
Primary port 4 status:
non-SAS transport, in hex:
00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
10 00 00 00 00 00 00 00 00 ........
Vendor specific [parameter_code=0x8000]:
00 80 00 43 06 31 17 00 00 00 02 ..C.1.....
Vendor specific [parameter_code=0x8003]:
00 80 03 43 08 00 00 00 00 00 00 00 00 ..C.........
Vendor specific [parameter_code=0x8010]:
00 80 10 43 08 00 00 00 00 00 00 00 00 ..C.........
Vendor specific [parameter_code=0x8020]:
00 80 20 43 12 00 00 00 00 00 00 00 00 00 00 00 00 . C.............
10 00 00 00 00 00 00 ......
Vendor specific [parameter_code=0xa101]:
00 a1 01 43 04 00 00 00 00 ..C.....
Vendor specific [parameter_code=0xa102]:
00 a1 02 43 04 00 00 00 00 ..C.....
TapeAlert response page (ssc-3, adc-3) [0x12]
Flag01h: 0 02h: 0 03h: 0 04h: 0 05h: 0 06h: 0 07h: 0 08h: 0
Flag09h: 0 0Ah: 0 0Bh: 0 0Ch: 0 0Dh: 0 0Eh: 0 0Fh: 0 10h: 0
Flag11h: 0 12h: 0 13h: 0 14h: 0 15h: 0 16h: 0 17h: 0 18h: 0
Flag19h: 0 1Ah: 0 1Bh: 0 1Ch: 0 1Dh: 0 1Eh: 0 1Fh: 0 20h: 0
Flag21h: 0 22h: 0 23h: 0 24h: 0 25h: 0 26h: 0 27h: 0 28h: 0
Flag29h: 0 2Ah: 0 2Bh: 0 2Ch: 0 2Dh: 0 2Eh: 0 2Fh: 0 30h: 0
Flag31h: 0 32h: 0 33h: 0 34h: 0 35h: 0 36h: 0 37h: 0 38h: 0
Flag39h: 0 3Ah: 0 3Bh: 0 3Ch: 0 3Dh: 0 3Eh: 0 3Fh: 0 40h: 0
Requested recovery page (ssc-3) [0x13]
Recovery procedures:
Recovery not requested
Device statistics page (ssc-3 and adc)
Lifetime media loads: 5288
Lifetime cleaning operations: 195
Lifetime power on hours: 48480
Lifetime media motion (head) hours: 12747
Lifetime metres of tape processed: 187049835
Lifetime media motion (head) hours when incompatible media last loaded: 0
Lifetime power on hours when last temperature condition occurred: 0
Lifetime power on hours when last power consumption condition occurred: 0
Media motion (head) hours since last successful cleaning operation: 66
Media motion (head) hours since 2nd to last successful cleaning: 126
Media motion (head) hours since 3rd to last successful cleaning: 187
Lifetime power on hours when last operator initiated forced reset
and/or emergency eject occurred: 20048
Lifetime power cycles: 77
Volume loads since last parameter reset: 5288
Hard write errors: 2
Hard read errors: 0
Duty cycle sample time (ms): 27276000
Read duty cycle: 0
Write duty cycle: 0
Activity duty cycle: 76
Volume not present duty cycle: 15
Drive manufacturer's serial number: 0
Drive serial number: 0
Medium removal prevented: 0
Maximum recommended mechanism temperature exceeded: 0
Media motion (head) hours for each medium type:
Density code: 0x44, Medium type: 0x0
Medium motion hours: 0
Density code: 0x44, Medium type: 0x1
Medium motion hours: 0
Density code: 0x46, Medium type: 0x0
Medium motion hours: 0
Density code: 0x46, Medium type: 0x1
Medium motion hours: 0
Density code: 0x58, Medium type: 0x0
Medium motion hours: 12747
Density code: 0x58, Medium type: 0x1
Medium motion hours: 0
Service buffer information page (adc-3) [0x15]
Service buffer identifier: 0x0
Buffer id: 0x41, tu=0, nmp=0, nmm=0, offline=0
pd=0, code_set: Binary, Service buffer title:
DT Device Error Log
Tape diagnostics data page (ssc-3) [0x16]
Parameter code: 0
Density code: 0x58
Medium type: 0x0
Lifetime media motion hours: 12739
Repeat: 0
Sense key: 0x3 [Medium Error]
Additional sense code: 0x0
Additional sense code qualifier: 0x2
[Additional sense: End-of-partition/medium detected]
Vendor specific code qualifier: 0x5098
Product revision level: 1228292954
Hours since last clean: 58
Operation code: 0x1d
Service action: 0x0
Medium id number (in hex):
00 49 43 32 47 4f 42 6e 36 38 30 00 00 00 00 00 00 IC2GOBn680......
10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Timestamp origin: 0x0
Timestamp:
00 00 00 00 09 6f 65
Parameter code: 1
Density code: 0x58
Medium type: 0x0
Lifetime media motion hours: 11121
Repeat: 0
Sense key: 0x3 [Medium Error]
Additional sense code: 0xc
Additional sense code qualifier: 0x0
[Additional sense: Write error]
Vendor specific code qualifier: 0x5083
Product revision level: 1228292954
Hours since last clean: 67
Operation code: 0x0
Service action: 0x0
Medium id number (in hex):
00 41 44 37 48 52 56 4e 55 58 4e 00 00 00 00 00 00 AD7HRVNUXN......
10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Timestamp origin: 0x0
Timestamp:
00 00 00 fb 62 2c 3e
Parameter code: 2
Density code: 0x58
Medium type: 0x0
Lifetime media motion hours: 1261
Repeat: 0
Sense key: 0x3 [Medium Error]
Additional sense code: 0x14
Additional sense code qualifier: 0x0
[Additional sense: Recorded entity not found]
Vendor specific code qualifier: 0x5090
Product revision level:...
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Content cut off. Read original on https://old.reddit.com/r/DataHoarder/comments/1czsqvv/lto_tape_capacity_do_tapes_lose_capacity_with_use/