Why a backup can look fine and still fail
Most offices find out their backup does not work on the worst possible day: the PC has died, the accountant is waiting, and the newest copy will not open. The reasons are usually small and boring:
- The backup stopped months ago and nobody noticed. A changed password, a full disk or a moved folder is enough.
- It backed up the wrong folder. The data was moved to another drive, or a new company or financial year was added somewhere else.
- The copy was taken while the data was open and is half-written.
- The file is there but damaged, on a failing pen drive or disk.
None of these show up until you try to open the backup. So the only real test is to restore it and look inside. It takes about fifteen minutes once a month.
The golden rule: restore beside, never over
Always restore a test copy into a new, separate folder or a new database name. Never restore over your live data to "check" a backup. If the backup is older than you think, or the wrong one, restoring over live data wipes everything entered since.
Do the test after office hours, or on a PC other than the main one if you can.
Testing Tally, Busy or Marg data
- Make a test folder on a drive with free space, for example
D:\RestoreTest. Do not use your live data folder. - Restore the newest backup into that folder, using your software's own restore option or by copying the backed-up data folder into it.
- Open the restored company from the test folder. In TallyPrime you can point the data path at the test folder when you open a company; in other software, use the option to open or select a company from a different folder.
- Check the data is recent and complete (see the checklist below).
- Close it, and delete the test folder, so nobody enters live work in the test copy by mistake.
If you have more than one company or financial year, test a different one each month so that over a few months every company has been opened at least once.
Testing a SQL Server database (ERP and billing software)
Restore the newest .bak file under a new database name with the MOVE option, so the test copy gets its own files and cannot touch the live database. The exact command is in our guide to automating SQL Server Express backups. Then point a copy of your software at the test database, or run a simple query, such as the latest bill date, and compare it with the live one. Drop the test database when you are done.
Testing office files
Pick five files at random from different folders, including one changed this week, restore them to a test folder, and open each one: an Excel sheet, a PDF, a scanned bill, a Word letter. A file that restores but will not open is the same as no file.
The checklist: what to look at
When the restored data is open, check:
- The latest entry. Is yesterday's last bill, voucher or receipt there? This tells you how old the backup really is.
- A balance you know. Cash or bank balance, a big party's outstanding, or stock of a fast item. Compare it with the live data as of the backup date.
- Every company. Are all companies and years in the list, including the newest?
- A report. Run a ledger or a GST report for last month. Damaged data often opens but fails on reports.
Write it down
Keep a simple log, on paper or in a sheet, one line per test:
| Date | Backup tested | Latest entry found | Problems | Checked by |
|---|---|---|---|---|
| 10-Nov-2026 | 9-Nov evening copy | Bill 4512, 9-Nov | None | Ramesh |
It takes a minute and it answers the question every owner should be able to answer: "When did we last prove our backup works?"
What to do if the test fails
- The newest copy is old: the backup has stopped. Find out why today: a full disk, a changed password or a moved folder are the usual reasons.
- It will not open: try the copy before it. If several fail, the backups are being taken while the data is in use, or the storage is failing.
- A company is missing: add its folder to the backup now.
Fix it, then test again the same week.
How JS1 Vault does the test for you
JS1 Vault runs this check itself. Once a month it restores a copy of each database on your PC under a new name, and opens it to prove it really comes back. Your data is backed up every evening, encrypted before it leaves the PC, kept in India and locked so nothing on the PC can delete it. When you do need data back, it comes back beside your live data, never over it: a JS1 technician restores databases, and folders can be brought back by your PC's Windows administrator from the JS1 Vault icon, or by our technician with you.
More reading: Google Drive, pen drive or online backup?, back up Tally data automatically and how long to keep business records in India.
See how JS1 Vault works and start a free trial.
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