Comment by CGamesPlay
4 years ago
> Clearly vendors and users are at odds with each other here; vendors want the best benchmarks (so you can sort by speed descending and pick the first one), but users want their files to exist after their power goes out.
I don't know, maybe if there was a "my files exist after the power goes out" column on the website, then I'd sort by that, too?
Ultimately the problem is on the review side. Probably because there's no money in it. There just aren't enough channels to sell that kind of content into, and it all seems relatively celebrity driven. That said, I bet there's room for a YouTube personality to produce weekly 10 minute videos where they torture hard-drives old and new - and torture them properly, with real scientific/journalistic integrity. So, basically you need to be an idealistic outspoken nerd and a little money to burn on HDDs and audio/video setup. Such a person would definitely have such a "column" included in their reviews!
(And they could review memory, too, and do backgrounder videos about standards and commonly available parts.)
>I don't know, maybe if there was a "my files exist after the power goes out" column on the website
more like, "don't lose the last 5 seconds of writes if the power goes out". If ordering is preserved you should keep your filesystem, just lose more writes than you expected.
I wouldn't expect ordering of writes to be preserved, absent a specific way of expressing that need, part of a write cache's job is reordering writes to be more efficient which means ordering is not generally preserved.
But then again, if they're willing to accept and confirm flush commands without flushing, I wouldn't expect them to actually follow ordering constraints.
>part of a write cache's job is reordering writes to be more efficient which means ordering is not generally preserved.
you can use some sort of WAL mechanism to ensure that the the parallel writes appear as if ordering was preserved. that will allow you to lie and ignore fsyncs, but still ensure consistency in case of a crash.
>But then again, if they're willing to accept and confirm flush commands without flushing, I wouldn't expect them to actually follow ordering constraints.
it depends on which type of liar they think you are. if they're the "don't care, disable all safeguards type", then yes they're probably ignoring ordering as well. However, it's also possible they're the methodical liar, figuring out what they can get away with. As I mentioned in another comment in this thread, as long as ordering is preserved the lie wouldn't be noticed in typical use cases (ie. not using it for some sort of prod db, and not using it as part of a multi-drive array). power losses are relatively common, and a drive that totally corrupts the filesystem on it will get noticed much more quickly than a drive that merely loses the last few seconds of writes.