PHP reads a file 8 KiB at a time by default. On a disk where every
request waits, such as a network or cloud volume, that made reading five
times slower: on the test server 5 MiB/s instead of 27 MiB/s. Without
PHP's read buffer every read of a blob is one request to the disk. The
same for packs on a local location.
The backup records the time of the folders with something in them, packed in the meta record,
so an older version still reads the snapshot. A restore through Nextcloud leaves a folder that
was already there alone. The round trip checks what Nextcloud shows, not only the disk.
Reported apart from unreadable files, with example paths and the advice to rename
them, instead of advice about permissions. Start of the 1.1.0 plan in PLAN.md.
- Leave out and report a file or folder whose name a snapshot cannot hold
- A staging write failure stops a full restore under --salvage
- Browse reuses its repository; empty folders read along with the entries
- Keep leases alive while empty folders are created; exact-prefix empty folder is the target
- Clean up tables that were partly created or before the transaction started
- Bin: no empty message after a read error; longer pages
- Record folders without files in the meta record of a snapshot and restore them (#27)
- Errors writing to the restore directory stop the restore, also with --salvage
- Resume: check the folder before skipping, clean temporaries in folders that are complete
- Clean only read-ahead folders of our own; refresh the lease on skipped files
- Drop tables a failed database restore created; keep --salvage from calling a restored database fresh
- Retry a pack that fails to open on the storage (SMB)
- Without cron, running backups take turns from the open page
- Bin: read in parts with a counter and progress bar, show read errors, refresh when a run ends
- The admin page and backup:status warn when background jobs do not run on a
system cron, or the cron stopped, with a link to how to set one up.
- Without a working system cron, the open admin page moves a running backup
forward through /api/tick, a short step per poll.
- The database phase shows the tables dumped ("db: 47/183 tables"); a backup
that has not moved for 15 minutes says it is waiting for background jobs.
- The trash of restore points is on a tab of its own, Bin.
- New screenshots; changelog and plan for 1.0.2.
On S3, index files and the tree segments read back when a snapshot is
written are fetched 16 at a time through the storage's S3 client
(IBackend::getRanges(), getMany()). Blobs that follow each other in a pack
are read as one range on every location. The snapshot is written in a step
of its own and the run shows "commit" meanwhile. On a 1 TB production
repository the check went from about 4 hours to 3.5 minutes.
backup:status and the web interface list the runs of the last 7 days,
running ones and at least the newest 5; --all / "Show older runs" list
all. Durations of a day or more show the days.
A run only showed "running (files)", which says nothing during a backup
of a terabyte. The files phase now records an expected size on its first
step: the previous snapshot's size, or for a first backup the users'
files, versions and trash from Nextcloud's file cache (approximate, shown
with a ~). The web interface and occ backup:status show the share of it
done so far, including a large file that is still being read; it stays
below 100% until the run finishes.
Storage and repository:
- Listing skipped every name containing ".part-", directories too, so the
exports of a user like "john.part-time" were invisible to prune on S3,
SFTP, FTP and SMB and their data was deleted. Only real temporary uploads
("<name>.part-<8 hex>") are skipped now.
- prune refuses to run while a recorded per-user export's manifest is
missing, instead of freeing that export's data.
- forget() and untrash() copy first, switch the catalog, and delete the
originals last, so a crash can no longer leave the catalog pointing at a
missing snapshot or database dump.
- Writes are checked against the expected size, so a short upload is an
error instead of a truncated pack; raw restores check rename() and touch().
- A catalog write refuses to overwrite a generation another process just
wrote, and the catalog lock lasts 300 s, so opening a large repository
inside it no longer lets the lease run out.
Backup runs and scheduling:
- A file that keeps changing is read again at most three times; then the
last read is kept and reported, instead of restarting forever and
blocking cleanup.
- Unreadable files and folders are recorded, logged, shown by occ
backup:run, stored in the snapshot and notified to admins, instead of
being skipped silently.
- After a failed scheduled backup, at most three attempts a day, an hour
apart, instead of a new run and notification every five minutes.
- The job no longer spins on a run whose lease another process holds, and
the weekly cleanup catches up after a Sunday spent backing up.
- Notifications for the per-user export retention events.
A full backup opened its repository at the start of a step and wrote the
catalog at the end of it, without the catalog lock. A per-user export or
restore that wrote the catalog in between could lose its entry, or the
snapshot could lose its own.
The final step now only stores the snapshot object and moves the run to a
new 'commit' phase. BackupService then records the snapshot under the
catalog lock, from a repository opened inside that lock; if the lock is
busy, the next step retries the commit. Repository::writeSnapshot() keeps
its old behaviour as putSnapshot() plus recordSnapshot().
TreeWalker walks one or more roots in a stable segment-wise order with
exclusions and resumes after a cursor; ParentCursor merge-joins the
previous snapshot in the same order. BackupRun no longer keeps a file
list or the parent's entries in memory or in its state.
- detect files changing during reading or between resumable steps and
re-read them (size/mtime/ctime/inode), spike F overwrites mid-run
- drop pending blob ids when a pack or index upload fails
- dump and restore PostgreSQL sequence state exactly, bound parameters,
validated catalog names; spike C checks all sequences exactly
- keep invalid UTF-8 byte-exact (tagged base64)
- refuse large tables without a primary key
- StorageBackend: check write/flush/close results, validate base path
- user_migration import/export: root paths, intermediate folders,
partial writes, read errors
- spikes: never touch an existing account, own fixtures, 512M note
BackupRun is a resumable state machine: each step works until a deadline,
uploads its pack and tree segment, and returns the state; large files are
resumed at the next blob. Snapshot is written last.
Spike F: 200 MiB file resumed across steps in separate processes; with 6
random kill -9 the run completes and restores bit-identically.
spikes/RESULTS.md summarises phase 0 and the findings for the plan.
dillard