On Fri, Jun 15, 2018 at 01:50:11PM -0700, Luis R. Rodriguez 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 XFS, 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.xfs 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: > > [10869.959501] device-mapper: zoned reclaim: (sda): Align zone 865 wp 28349 to 30842 (wp+2493) blocks failed -5 > [10870.014488] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE > [10870.016137] sd 0:0:0:0: [sda] tag#0 Sense Key : Illegal Request [current] > [10870.017696] sd 0:0:0:0: [sda] tag#0 Add. Sense: Unaligned write command > > We have to prevent these mistakes by avoiding mkfs.xfs use on zoned disks. > > Note that this not enough yet, if users are on old AHCI controllers, > the disks may not be detected as zoned. More work through udev may be > required to detect this situation old old parent PCI IDs for zoned > disks, and then prevent their use somehow. > > If you are stuck on using XFS there a udev rule out there [0], this is > far from perfect, and not fully what we want done upstream on Linux > distributions long term but it should at least help developers for now > enjoy their shiny big fat zoned disks with XFS. > > This check should help avoid having folks shoot themselves in the foot > for now with zoned disks. If you make the mistake to use mkfs.xfs > on a zoned disk, you will now get: > > # mkfs.xfs /dev/sda > /dev/sda: zoned disk detected, refer to dm-zoned-tools for how to use with XFS Shouldn't this code be put in libblkid() so it's available to all filesystem tools, not just XFS? Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
