News for hackers. Stuff that matters.

A comment on I tested four NVMe SSDs from four vendors – half lose FLUSH'd data on power loss. Parent comment

Re:I tested four NVMe SSDs from four vendors – half lose FLU... by lxgr on Wednesday November 22, 2023 @12:49AM (#38375156)
At least for ext4 and actually written data (i.e. not ftruncate’d files), I believe zeroes should really not occur.

Both extents and the file size are metadata as far as I understand, which would be atomically updated through the journal.

Data can be written before metadata (in data=ordered mode):

> All data are forced directly out to the main file system prior to its metadata being committed to the journal.

[ Parent | on HN ]
Re:I tested four NVMe SSDs from four vendors – half lose FLU... by Filligree on Wednesday November 22, 2023 @01:02AM (#38375245)
Is data=ordered the default?
[ Parent | on HN ]
Re:I tested four NVMe SSDs from four vendors – half lose FLU... by lxgr on Wednesday November 22, 2023 @09:13AM (#38379409)
As far as I can tell it's always been on both ext3 and ext4, yes.
[ Parent | on HN ]