On Jun 15, 2018, at 6:28 PM, Andreas Dilger <adilger@xxxxxxxxx> wrote: > > On Jun 15, 2018, at 2:56 PM, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote: >> >> Using raw zoned disks by filesystems requires special handling, only >> f2fs currently supports this. All other filesystems do not support >> dealing with zoned disks directly. >> >> As such using raw zoned disks is not supported by e2fsprogs, to use them you >> need to use dm-zoned-tools, format them with dzadm, set the scheduler to >> deadline, and then setup a dmsetup with zoned type, and somehow set >> this up on every boot to live a semi-happy life for now. >> >> Even if you use dmsetup on every boot, the zoned disk is still exposed, >> and a user may still think they have to run mkfs.ext[234] on it instead >> of the /dev/mapper/ disk, and then mount it by mistake. >> >> In either case you may seem to believe your disk works and only eventually >> end up with alignmet issues and perhaps lose you data. For instance the >> below was observed with XFS but its expected ext[234] users would see >> the same: > > If you are interested in ext4 and SMR drives, there were some patches > developed to allow ext4 to work on zoned disks, essentially converting > it to be a "lazy-journal log-structured" filesystem. That makes almost > all of the filesystem IO linear (though we could avoid duplicate journal > writes by writing large IOs directly to disk). > > This was presented at FAST'17 as "ext4-lazy", though I'm unable to find the > patch that implemented this feature (it is not landed in the kernel yet). > > Maybe Ted could send out a URL for the patch, even if it is a WIP? To reply to my own email, I found the patch in question: https://github.com/tytso/ext4-patch-queue/blob/master/add-ext4-journal-lazy-mount-option it wasn't showing up in any of my searching. Cheers, Andreas
Attachment:
signature.asc
Description: Message signed with OpenPGP
