I''m curious about if there are any potential problems with using LVM metadevices as ZFS zpool targets. I have a couple of situations where using a device directly by ZFS causes errors on the console about "Bus and lots of "stalled" I/O. But as soon as I wrap that device inside an LVM metadevice and then use it in the ZFS zpool things work perfectly fine and smoothly (no stalls). Situation 1 is when trying to use Intel X25-E or X25-M SSD disks in a Sun X4240 server with the LSI SAS controller - I never could get things to run without errors no matter what. (Tried multiple LSI controllers and multiple SSD disks). Jul 8 09:43:31 merope scsi: [ID 365881 kern.info] /pci at 0,0/pci10de,375 at f/pci1000,3150 at 0 (mpt0): Jul 8 09:43:31 merope Log info 31126000 received for target 15. Jul 8 09:43:31 merope scsi_status=0, ioc_status=804b, scsi_state=c Jul 8 09:43:31 merope scsi: [ID 365881 kern.info] /pci at 0,0/pci10de,375 at f/pci1000,3150 at 0 (mpt0): Jul 8 09:43:31 merope Log info 31126000 received for target 15. Jul 8 09:43:31 merope scsi_status=0, ioc_status=804b, scsi_state=c Jul 8 09:43:31 merope scsi: [ID 107833 kern.warning] WARNING: /pci at 0,0/pci10de,375 at f/pci1000,3150 at 0/sd at f,0 (sd32): Jul 8 09:43:31 merope Error for Command: write Error Level: Retryable Jul 8 09:43:31 merope scsi: [ID 107833 kern.notice] Requested Block: 64256 Error Block: 64256 Jul 8 09:43:31 merope scsi: [ID 107833 kern.notice] Vendor: ATA Serial Number: CVEM8493 00BM Jul 8 09:43:31 merope scsi: [ID 107833 kern.notice] Sense Key: Unit Attention Jul 8 09:43:31 merope scsi: [ID 107833 kern.notice] ASC: 0x29 (power on, reset, or bus reset occurred), ASCQ: 0x0, FRU : 0x0 Situation 2 is when I installed an X25-E in a X4500 Thumper. Here I didn''t see any errors on the console of the server, but performance would at regular intervals "drop" to zero (felt the same as in the LSI case above, just without the console errors). (In situation 1 above things would work perfectly fine when I was using an Adaptec controller instead). Anyway, when I put the 4GB partition of that SSD disk that I was using for testing inside a simple LVM metadevice all errors vanished and performance increased many many times. And no "hickups". But I wonder... Is there anything in a setup like this that might be dangerous - something that might come back and bite me in the future? LVM(disksuite) is really mature technology and something I''ve been using without problems on many servers for many years so I think it can be trusted but anyway...? (I use the partition of that SSD-in-a-LVM-metadevice as a SLOG device for the ZFS zpools on those servers and performance is now really *really* good). -- This message posted from opensolaris.org