Re: Linux does not care for data integrity (was: Disk write cache)

Arjan van de Ven
2005-05-16T11:12:42Z

> and
> request that the kernel switches off the drive's write cache in all
> drives unless the whole fsync() stuff works (unless defeated by a
> "benchmark" kernel boot parameter).

I think you missed the part where disabling the writecache decreases the
mtbf of your disk by like a factor 100 or so. At which point your
dataloss opportunity INCREASES by doing this.

Sure you can waive rethorics around, but the fact is that linux is
improving; there now is write barrier support for ext3 (and I assume
reiserfs) for at least IDE and iirc selected scsi too.

Lets repeat that again: disabling the writecache altogether is bad for
your disk. really bad. Barriers aren't brilliant for it either but a
heck of a lot better. Lacking barriers, it's probably safer for your
data to have write cache on than off.