Found at 0x0, and every 262144 bytes thereafter (every 256KB), and all have a similar preamble.
00000000 56 4F 4C 31 35 55 58 32 39 39 20 20 20 20 20 20 20 20 20 20 20 4E 45 54 57 4F 52 4B 45 52 20 20 VOL15UX299 NETWORKER
00000020 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
00000040 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 33 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3................
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 04 00 00 ................................
00000080 00 00 00 05 0B 1A B3 8B 5F 1A B3 8B 18 F6 36 A0 C0 E9 07 9F 00 00 00 02 00 00 00 00 00 04 00 00 ........_.....6.................
000000A0 00 00 00 09 00 00 00 09 00 00 00 1D 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................................
000000C0 00 00 01 0C 00 00 00 01 00 00 00 06 CB 1C 15 A8 5F 1C 15 A8 1E 36 36 A0 C0 E9 07 9F 00 00 00 00 ................_....66.........00040000 56 4F 4C 31 35 55 58 32 39 39 20 20 20 20 20 20 20 20 20 20 20 4E 45 54 57 4F 52 4B 45 52 20 20 VOL15UX299 NETWORKER
00040020 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
00040040 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 33 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3................
00040060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 04 00 00 ................................
00040080 00 00 00 05 0B 1A B3 8B 5F 1A B3 8B 18 F6 36 A0 C0 E9 07 9F 00 00 00 02 00 00 00 01 00 04 00 00 ........_.....6.................
000400A0 00 00 00 06 00 00 00 06 CB 1C 15 A8 5F 1C 15 A8 1E 36 36 A0 C0 E9 07 9F 00 00 00 00 00 03 8E 6C ............_....66............l
000400C0 00 01 AE 8C DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD ................................00080000 56 4F 4C 31 35 55 58 32 39 39 20 20 20 20 20 20 20 20 20 20 20 4E 45 54 57 4F 52 4B 45 52 20 20 VOL15UX299 NETWORKER
00080020 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
00080040 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 33 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3................
00080060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 04 00 00 ................................
00080080 00 00 00 05 0B 1A B3 8B 5F 1A B3 8B 18 F6 36 A0 C0 E9 07 9F 00 00 00 02 00 00 00 02 00 04 00 00 ........_.....6.................
000800A0 00 00 00 04 00 00 00 06 CC 1C 15 A8 5F 1C 15 A8 1E 35 36 A0 C0 E9 07 9F 00 00 00 00 00 00 2B 14 ............_....56...........+.
000800C0 00 00 E4 74 DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD ...t............................000C0000 56 4F 4C 31 35 55 58 32 39 39 20 20 20 20 20 20 20 20 20 20 20 4E 45 54 57 4F 52 4B 45 52 20 20 VOL15UX299 NETWORKER
000C0020 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
000C0040 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 33 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3................
000C0060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 04 00 00 ................................
000C0080 00 00 00 05 0B 1A B3 8B 5F 1A B3 8B 18 F6 36 A0 C0 E9 07 9F 00 00 00 02 00 00 00 03 00 04 00 00 ........_.....6.................
000C00A0 00 00 00 06 00 00 00 06 CA 1C 15 A8 5F 1C 15 A8 1E 37 36 A0 C0 E9 07 9F 00 00 00 00 00 02 2F E4 ............_....76.........../.
000C00C0 00 00 60 14 DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD ..`.............................Majourity of these are sparse and only filled with ‘DD’ values. Large but empty files?
Some are not though, and have data right up the end end of the block. This looks like a file continuation.
0017FFE0 6E 76 64 75 6D 70 3A 20 20 20 20 20 20 20 20 20 48 49 53 54 53 49 5A 45 3D 31 30 30 30 0A 20 31 nvdump: HISTSIZE=1000. 1
00180000 56 4F 4C 31 35 55 58 32 39 39 20 20 20 20 20 20 20 20 20 20 20 4E 45 54 57 4F 52 4B 45 52 20 20 VOL15UX299 NETWORKER
00180020 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
00180040 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 33 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3................
00180060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 00 04 00 00 ................................
00180080 00 00 00 05 0B 1A B3 8B 5F 1A B3 8B 18 F6 36 A0 C0 E9 07 9F 00 00 00 02 00 00 00 06 00 04 00 00 ........_.....6.................
001800A0 00 00 00 05 00 00 00 06 CA 1C 15 A8 5F 1C 15 A8 1E 37 36 A0 C0 E9 07 9F 00 00 00 00 00 05 AA F8 ............_....76.............
001800C0 00 00 52 58 33 2E 32 38 2E 30 30 20 4D 51 20 72 31 65 6E 76 64 75 6D 70 3A 20 20 20 20 20 20 20 ..RX3.28.00 MQ r1envdump:
001800E0 20 20 48 4F 4D 45 3D 2F 71 61 2F 65 64 61 71 61 0A 20 31 33 2E 32 38 2E 30 30 20 4D 51 20 72 31 HOME=/qa/edaqa. 13.28.00 MQ r1