Chapter 323: Climate-Controlled Storage and Cold Data

1:20 PM. The phone vibrated on the desk. Old Zhou sent a photo and a voice message. The photo was a scanned copy of a yellowed ledger, its edges curled and the red official stamp blurred, but the entry date was clear: November 12, 2016. The voice message was layered with the sound of wind and the crisp click of a lighter opening and closing. “Mr. Lin, found them. Three LTO-5 tapes, serial numbers ending in 047, 048, and 049. The warehouse is in the logistics park converted from the old textile machinery factory in the northern suburbs, Gate 4, Zone B. It’s now managed by an outsourcing company for the municipal archives. You need to report in advance with your ID and a company introduction letter. I’ve already made arrangements. When you get there, look for Old Wu on duty. Just a heads-up: those tapes have been sitting for seven years. The dehumidifier in the climate-controlled room broke down for a stretch last year, so the labels might be brittle and the casings a bit sticky.”

Lin Chen replied: “Received. The letter has been issued.” He screenshotted the PDF with the official seal and forwarded it to Su Man. She replied instantly: “Printed and bagged. Stress test latency is stable at 180 milliseconds. Drive safely, and don’t push your foot.”

He turned off his phone and pulled open the drawer. He took out anti-static gloves, a lint-free cloth, a portable LTO-5 reader (procured overnight at a premium on a second-hand platform and delivered via same-city flash courier), and a paper copy of the Data Asset Access Application Form. He stuffed the reader into his backpack and zipped it all the way up. He slipped a new silicone insole into his left shoe, retied the laces, and secured them with a double knot. As he stood, his knee gave a faint ache. He braced himself against the edge of the desk to straighten up, without pausing.

2:00 PM sharp. The elevator descended. The cold air of the underground garage hit him, carrying the sharp scent of gasoline. He opened the car door, slid into the driver’s seat, adjusted the seat, fastened his seatbelt, and turned the ignition. He set the navigation: Northern Suburbs Old Textile Machinery Factory Logistics Park. Estimated travel time: forty-five minutes.

The city overpasses gleamed a dull gray-white under the afternoon sun. Traffic crawled, brake lights stretching into a continuous red ribbon. Lin Chen modulated the throttle with his right foot, keeping his left foot hovering lightly beside the pedal to avoid bearing weight. He turned on the car Bluetooth and played a track of white noise. His mind automatically broke down the upcoming steps: entry verification → sign confidentiality agreement → don dust suit → Old Wu guides → locate shelf → visual inspection → power on reader → export manifest → hash comparison → sign out. Every step had a contingency plan. If the reader failed to recognize the old tapes, the backup was to contact the provincial university of technology lab for legacy equipment. If the labels had peeled off, he would reverse-engineer the physical location using the ledger’s serial numbers. If the data was corrupted, he would cross-reference it with the RAID mirror records from the 2016 migration logs. No gambling on luck. Only calculating probabilities.

3:10 PM. The navigation chimed: “You have arrived near your destination.” Lin Chen turned onto a service road. The asphalt was cracked, flanked by faded factory walls and rusted gantry cranes. The iron gate of the logistics park stood half-open. An old man in a worn uniform sat in the guard booth. Lin Chen handed over his ID and the introduction letter. The man checked them, made a phone call. Five minutes later, a man in his fifties wearing gray work clothes walked out, a badge on his chest reading “Warehouse Supervisor: Wu Jianguo.”

“Mr. Lin?” Old Wu sized him up, his gaze lingering for half a second on Lin Chen’s slight limp before he asked no further questions. “Old Zhou called. Follow me. The warehouse is on the second basement level. It’s climate-controlled, but the ventilation is mediocre. Keep your mask on.”

Lin Chen nodded. They walked through a dim corridor, swiped a card, and descended the stairs. The air turned abruptly cold, carrying a mixed smell of old paper and aged plastic. The underground storage area was vast, rows of metal shelving stretching to the limits of sight. Old Wu switched on his headlamp, its beam cutting through the suspended dust. “The 2016 batch is over there. Zone C, Row 7.”

Top shelf. Three dark blue plastic cases, coated in a thin layer of dust. Lin Chen put on his gloves and carefully lifted them down. The cases showed minor surface scratches, but the sealing strips were intact. He opened a lid. Three LTO-5 tapes lay quietly in anti-vibration foam. The label paper had yellowed and curled at the edges, but the handwritten serial numbers were still legible: NAS-02-COLD-047, 048, 049. They matched the ledger exactly.

“Can you read them directly?” Old Wu asked.

“Need to run a power test.” Lin Chen took out the reader and connected it to a power bank. The indicator light came on. He inserted tape 047. The mechanical drive emitted a soft click. The screen displayed a progress bar: Identifying media... Reading...

During the thirty-second wait, Lin Chen stared at the screen. A dull throb pulsed in his left foot. He shifted his weight, leaning against a shelf upright. Sweat traced down his temple. He didn’t wipe it away.

Read successful. Capacity: 1.42TB. File system: EXT3. He exported the directory manifest. A TXT file generated. He scrolled through it quickly. The file naming conventions were standardized, the timestamps continuous. No garbled characters.

“048.” He swapped the tape. Click. Progress bar. Read successful. Capacity: 1.38TB. Manifest exported. “049.” The third tape. Click. The progress bar moved halfway, then suddenly froze. The screen flickered. Error: Media surface scratched. Partial sectors unreadable.

Lin Chen’s brow furrowed slightly. He took out the lint-free cloth and gently wiped the edge of the tape. He reinserted it and initiated another read. The progress bar advanced slowly, stalling again at 92%. Warning: Logical Block Address LBA 44012-44105 damaged.

“Is it broken?” Old Wu leaned in.

“Physical damage. It won’t affect the manifest export.” Lin Chen’s voice remained steady. He pulled up the reader’s low-level logs, manually bypassed the damaged sectors, and forced an export of the remaining directory. The file generated. He compared the three manifests. 047 and 048 were complete. 049 was missing approximately 1.2GB of cold data, primarily consisting of image archive backups from October 2016.

He opened his error notebook. On a fresh page, he wrote: Tape 049 LBA damaged. Missing 1.2GB. Need to verify if this is a redundant backup or core clinical data.

He opened his laptop, connected the reader, and wrote a verification script. He cross-referenced the hash values of the three manifests against the original manifest in the 2016 migration logs. The script ran. Three minutes later, it output the result: 047/048 exact match. 049 missing segment corresponds to log note: 'Duplicate verification disk, RAID1 mirrored, not unique source'.

Lin Chen let out a long breath. Not core data. A redundant disk. Compliance required “proof of original physical media sealing” and “data integrity traceability.” As long as he could prove the missing portion had a mirrored backup and did not break the lineage chain of the primary dataset, it would pass the audit.

He picked up a pen and filled in the read results on the access form. Old Wu watched from the side and handed him an ink pad. “Press your thumbprint. Warehouse rule: leave a trace for entry and exit.”

Lin Chen pressed his thumb down. The red ink left a clear impression. He packed up his equipment, returned the tapes to their plastic cases exactly as they were, and snapped the lids shut. Old Wu led him back to the surface. The sunlight was blinding. Lin Chen squinted, got back into his car, and closed the door.

4:20 PM. He dialed Su Man’s number. “I have the manifests. Tape 049 has physical damage, but the missing segment is RAID1 redundant and doesn’t affect the main chain. I’ve packaged the read logs and the hash comparison report. Run attachment thirteen of the compliance template. Highlight ‘non-core redundant disk damaged, primary data lineage intact.’” “Understood.” The rapid clatter of keyboards came through the line. “I’ll finalize the materials tonight. Submit for preliminary review before 10 AM tomorrow. How’s your foot?” “It’s fine.” Lin Chen hung up.

He leaned back against the seat and closed his eyes. The cabin was quiet, save for the faint hum of air from the AC vents. He opened his eyes, took out the error notebook, and drew a heavy checkmark next to Locate tape library. Extract archive manifest. Complete lineage chain.

The phone screen lit up. Enterprise WeChat. Provincial Health Commission, Science and Technology Division. New message: Preliminary materials received. Entering formal review stage. Please prepare: 1. On-site photos of media sealing (with timestamp watermark); 2. Scanned originals bearing dual signatures; 3. Third-party data integrity appraisal report (must hold CMA accreditation). Supplement window: 72 hours.

Lin Chen stared at the screen. 72 hours. CMA accreditation. Third-party appraisal.

He set the phone down and restarted the car. The engine purred to life. He turned the wheel around and merged onto the overpass heading back into the city. In the rearview mirror, the iron gate of the logistics park shrank, gradually dissolving into the gray-yellow fringe of the urban sprawl. He opened his browser and searched for “Directory of Provincial CMA-Certified Data Appraisal Institutions.” The list was long. He verified their business scopes, scheduling availability, and quotes one by one. His finger glided across the trackpad, the cold screen light reflecting on his face.

Countdown: three days. The appraisal agency’s schedule had to be locked in tonight.