lumentoKEEP
An eye on your NAS, in plain words. KEEP tells you when a backup has failed or leaves a share out, checks the safety features most people never look at, and watches your photos for bit rot: silent damage no one notices until the photo won't open. It only reads. When a file has gone bad, it tells you which one, finds the copy in your backup and checks that the copy is still good.
It changes nothing you value.
KEEP only reads your files, and the Linux kernel stops it from writing to them. We tested that on a real NAS: KEEP's self-test tried 51 different ways to change a file, and the kernel refused every one. It never repairs, never copies over a file and never writes into a share. The only things it writes are its own index, its own pages and its own log lines.
That's a deliberate limit. A tool that fixes files can also break them. KEEP finds the problem and you decide what to do, in ADM, with your own hands.
Notice it early.
Know where to look.
Checks your backups
Backups can fail without a word. KEEP reads your backup jobs, local, USB and remote, and tells you when one fails, stalls, is overdue or has never finished, and why, such as a USB disk that refuses some file names. It lists shares no backup covers, and you can mark the ones that don't need one.
Spots a weak backup
A backup can run every night and still let you down. KEEP warns when a backup keeps only one copy, so a damaged photo can overwrite the good one, when its disk can't catch damage itself, and when its encrypted destination is locked.
Checks the NAS's own safety features
Snapshots that are missing, stale or writable. Scrubs and RAID checks that never run or found errors. A mirror running on one disk. KEEP reads them all and says what to do in ADM.
Finds silent damage
A file can change on disk with no error and no warning. KEEP keeps a SHA-256 fingerprint of each file and checks it again later. If the bytes changed and nothing you did explains it, KEEP flags the file. It also catches damage a file system's own checksums can miss, such as a file written wrong by failing memory.
Tells an edit from damage
If you edit a photo, that isn't damage. KEEP looks at the file in pieces to tell the two apart, reads it a second time before it raises the alarm, and knows a file you've only moved. It never stops to ask you. One limit: damage at the very start of a file that also looks edited reads as an edit.
Names the file
You get the file's name and what's wrong with it: damaged, unreadable or missing. You don't get a vague warning that something somewhere is off.
Proves the good copy is good
KEEP finds the damaged file's copy in your backup, reads it and checks it against the fingerprint, so you know the copy is intact before you restore it. It never touches the copy. You restore it yourself in ADM.
Speaks through ADM
Notices go to ADM's own System log, where you already look, once per change and never repeated. KEEP also checks that ADM will email you when something fails. Its admin page shows each finding as a card, sorted by how urgent it is, with what to do in ADM.
Stays out of your backups' way
When you set it up, KEEP suggests a nightly reading window that misses your backups and scrubs, and it reads nothing until you pick one. If a backup runs anyway, KEEP pauses and says so.
Light on the NAS
It runs at idle priority, pauses while the RAID syncs or scrubs, only reads inside your nightly window, and can stop after a limit you choose. Upgrades keep its data, and it comes back by itself after a reboot.
Honest about its limits
Some file systems already checksum your data and some, like ext4, don't. KEEP says which you have, and says plainly when it can't promise something. Every piece of advice it gives, with its sources, is on what KEEP teaches.
Index, compare,
tell you.
Your NAS may already catch some damage. KEEP adds the part it can't: a second, independent record of what each file should contain.
- Install lumento KEEP from App Central and set a password on its admin page.
- Choose when it reads. Pick a nightly window, and each night KEEP reads your photos and records a fingerprint for each. It throttles itself, so the NAS stays usable.
- It compares. On the next pass, a file whose contents changed with no matching edit is flagged. A file that's now unreadable or missing is flagged too.
- You hear about it. KEEP writes to ADM's System log and shows the finding on its admin page, with where a good copy may be.
- You restore. Use ADM to bring back the good copy. KEEP never does it for you.
Tested on a real NAS. Not yet released.
Built
- A read-only walk of the share, with the kernel as the guard
- Fingerprints and the index
- Sorting edits from damage
- Proving the backup copy is good
- Backup jobs, local, USB and remote: failed, stalled, overdue or never run
- Shares no backup covers
- Weak backups: one copy only, a disk that can't catch damage, a locked destination
- Checks on scrubs, snapshots, RAID and file system error counts
- A check that ADM will email you when something fails
- Notices in ADM's System log
- The admin page
- Installed and tested on a real Asustor NAS: the write self-test, upgrades and reboots
Next
- Watching every share, not just Photos, including encrypted ones
- Advice updates from lumento.one, with an off switch
- An optional check that finds which disk of a mirror holds the bad copy
Platform
- Asustor ADM 5.1 or later, x86-64 and ARM
- The core is built to be the same on any NAS
- Synology, QNAP and TrueNAS are under consideration
