4. Popular symptoms of damaged HDD
● BSOD
● Hard drive makes strange noises
● “Disk not formatted” messages
● Cyclic reboot
● The system slows down or hangs
● Drive or device not found
● Operating system not found
7. Common damages of HDD
● Unreadable sectors of the hard drive
● Faulty electronics board
● Malfunction of the magnetic head unit
● Switch failure
● Wedge engine hard drive
● Sticking of magnetic heads
8. What is test data?
Data that exists (for example, in a database) before a test is
executed, and that affects or is affected by the component or
system under test.
9. Test data. Types
REAL / LIVE SYNTHETIC / EMULATED
+ diverse
+ close to production (unforeseen
cases)
+ fast to generate or emulate
+ accurate
+ sharpened for our needs (autotests)
- bulky
- changeable
- complexities with testing of
negative cases
- can be changed or lost
- knowledge and technical details are
needed
- needs to redo the existing system
- time to create subsystems
10. Test data. Disks
- REAL data > EMULATED data
- Health disks monitoring
- New data disk
(buy, get from clients or made it yourself)
- Drives with unique behavior
- Negative testing -> dead HDDs
- Probabilistic problems and freezes
- Continuous research
11. Test data. Amount of cases
Manufacturers
Hitachi, WD, Seagate, Toshiba, Samsung, Fujitsu, Kingston, Transcend, HP, IBM and
many others
Types of Data
Storages
IDE HDD, SATA HDD, SATA SSD, SAS HDD, USB HDD, USB flash, SD cards, M2 SATA
PCIe, Apple SSD PCIe
Adapters SATA-USB, IDE-SATA, Card readers
Models Each manufacturer has more than 100 different models of disks
Disk firmwares Each model can have several versions of firmware
Types of failures 6 groups of popular failures, each one has own algorithm to prevent or fix problems
Disk Health and
Operating time
Disk can work without degrading ~ 2-4 years, and after damage - nobody knows
Cases are listed only for one
feature
12. Test data. Emulators
- Research about similar behaviors of HDD
- Change application architecture for Emulator system
implementation
- JIRA issues called “Test everything and more”
✓ Time saved
✓ Rescued drives
✓ Short test cases (configuration files)
✓ Ability to make specific tests
− Not everything can be emulated
13. Test data. OS Etalons
- OS: NTFS, FAT16, FAT32, exFAT, ext2, ext3, ext4,
HFS, HFS+, HFSx
- more than 20 factors affecting the algorithm
- backups of HDD’s
Etalons:
- with clean operating systems for installation test
- with different OS
- different amount, size, type and fragmentation of
files
- image files with core structures of OS
14. Test data. Installations
- HDD with all supported OS to install
- Before testing - make copy for yourself
(~ 1 day to copy all needed disk)
- Clean OS for installation without updates
(~ 2 days to get updates)
- Drivers, libraries, creating DB, antiviruses,
firewalls
- Test stands
15. Test data. DB and Case Management
- Copies of production databases
- Non-disclosure agreements
- Backing up the database of all product versions
(testing the upgrade - downgrade)
- Cases with major changes in releases
(each version of DB backup contains such changelog cases)
16. Test data. Performance
- Special HDD’s to test performance
- Performance disks with more than
500 TB amount of recorded data
- Performance test plans
- Highly specialized knowledge
(performance issues with JIT compilation or SSD Garbage
Collection in used cells)
17. Test data. Hardware
- Main testers are electronic engineers
- Test data:
- cables, boards, adapters …
- levels of current, voltage …
- statics and other physical issues
- Special software to test quality
of units assembly
18. Test data. Preparation time
Research market and buy new disks 1-4 hours
Wait for disk to arrive in our office 1-4 week
Install OS to disk 1-3 hours
Make partitions with required test data 0.5 hours - 2 days
Generate needed data to test DB 1 - 4 hours
Copy disk to disk (make image) 1 - 5 hours
Copy from image file to disk 2 - 10 hours
Fill or Erase disk 1 - 5 hours
Wait for OS updates to test installations 1 - 2 days
19. Results
- Much attention is paid to data preparation
- Preparation takes a lot of time
- Real and emulated data combination
- Large amounts of data that can not be stored in the database
- Test data generators are not suitable for our purposes
- Test design techniques for test data preparation
(pairwise, boundary value analysis, decision table testing, equivalence partitioning)
- Mind maps, checklists, user stories
