From: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> Neil, I have been hitting issues with discard being ridiculously slow on arrays with certain typs of SSDs that seem to serialize discard processing. This is particularly bad as I have seen systems where the IMSM BIOS defaults to 4KB chunk size, combined with these badly performing drives, it could bump the mkfs on an array from seconds to over 40 minutes. Most users will stick to the defaults and then hit the problem during install without understanding why it goes wrong :( The problem is that there is no way to benchmark our way to this or somehow test if a drive performs discard at reasonable speed. I suggest we take an approach similar to that of RAID456 and default to disabling discard, except for the case where the user knows the drives are safe. Thoughts? Cheers, Jes Jes Sorensen (1): raid0: Disable discard per default due to performance uncertainty drivers/md/raid0.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
