In computer file systems, soft updates is an approach to maintaining disk integrity after a crash or power outage. They are an alternative to journaling file system.
Instead of duplicating metadata writes in a journal, soft updates work by tracking and enforcing metadata update dependencies. Like journaling, soft updates do not guarantee that no data will be lost, but they do make sure the filesystem is consistent.
An advantage of a file system with soft updates is that it can be mounted immediately after a crash since there is no log replay.
Soft updates were first introduced to FreeBSD by Marshall Kirk McKusick and are now available across the BSDs. Recent versions of soft updates include a journaling mechanism which eliminates the need for a background fsck after a crash.
Read more about Soft Updates: Operation
Famous quotes containing the word soft:
“Since time immemorial, one the dry earth, scraped to the bone, of this immeasurable country, a few men travelled ceaselessly, they owned nothing, but they served no one, free and wretched lords in a strange kingdom. Janine did not know why this idea filled her with a sadness so soft and so vast that she closed her eyes. She only knew that this kingdom, which had always been promised to her would never be her, never again, except at this moment.”
—Albert Camus 1013–1960, French-Algerian novelist, dramatist, philosopher. Janine in Algeria, in The Fall, p. 27, Gallimard (9157)