Re: Marvell 88e8057, and SATA disk cache flushing?
On Sat, Oct 22, 2011 at 11:42 AM, james wrote: > I need to replace my old NAS and I have some hardware to use, but plan A > failed dismally because Illumos does not have a working driver for the > Marvell 88e8057 GegE chip on my Saphire mobo - an AMD E350 device which I > have in a small case (otherwise I'd just add another NIC). > > So: > > 1) does dragonfly support this chip? I believe the msk driver does. > Also - while I'm attracted to swap cache (and I have an SSD that I would > have used as boot, L2ARC and ZIL) I'm a little concerned that the situation > with flushing caches on hard disks isn't as clear as it is with ZFS, which I > trust to use write back cackes and flush explicitly. > > So: > > 2) Does Dragonfly have proper support for flushing write back caches on SATA > drives? > > I have read the notes on 'fsync flush modes' in hammer(8), but this does not > discuss whether fsync writes to the drive assuming write-through, or forces > a drive cache flush. > > I'm also interested in whether such flushes will work if I configure the > 4-off 2TB drives as a software RAID5 array. HAMMER explicitly flushes drive caches. Our device-mapper linear target does forward FLUSH commands to backing devices. I don't know about vinum, unfortunately. At first skim of vinumstart(), it doesn't, but I only quickly scanned it. UFS does not ever flush drive caches. Boo. --vs;
Re: Marvell 88e8057, and SATA disk cache flushing?
The easy way to find out is to download a recent DragonFly iso or img and boot it; they are live images, and if they work when it boots off a CD/DVD/USB stick, you're set. I don't know about the cache flushing, but I'll note that Hammer does not have a RAID mechanism. It works through master/slave mirroring. I think you can use vinum, but I'd recommend using hardware RAID if possible. On Sat, Oct 22, 2011 at 11:42 AM, james wrote: > I need to replace my old NAS and I have some hardware to use, but plan A > failed dismally because Illumos does not have a working driver for the > Marvell 88e8057 GegE chip on my Saphire mobo - an AMD E350 device which I > have in a small case (otherwise I'd just add another NIC). > > So: > > 1) does dragonfly support this chip? > > Also - while I'm attracted to swap cache (and I have an SSD that I would > have used as boot, L2ARC and ZIL) I'm a little concerned that the situation > with flushing caches on hard disks isn't as clear as it is with ZFS, which I > trust to use write back cackes and flush explicitly. > > So: > > 2) Does Dragonfly have proper support for flushing write back caches on > SATA drives? > > I have read the notes on 'fsync flush modes' in hammer(8), but this does > not discuss whether fsync writes to the drive assuming write-through, or > forces a drive cache flush. > > I'm also interested in whether such flushes will work if I configure the > 4-off 2TB drives as a software RAID5 array. > > Thanks > James >
Marvell 88e8057, and SATA disk cache flushing?
I need to replace my old NAS and I have some hardware to use, but plan A failed dismally because Illumos does not have a working driver for the Marvell 88e8057 GegE chip on my Saphire mobo - an AMD E350 device which I have in a small case (otherwise I'd just add another NIC). So: 1) does dragonfly support this chip? Also - while I'm attracted to swap cache (and I have an SSD that I would have used as boot, L2ARC and ZIL) I'm a little concerned that the situation with flushing caches on hard disks isn't as clear as it is with ZFS, which I trust to use write back cackes and flush explicitly. So: 2) Does Dragonfly have proper support for flushing write back caches on SATA drives? I have read the notes on 'fsync flush modes' in hammer(8), but this does not discuss whether fsync writes to the drive assuming write-through, or forces a drive cache flush. I'm also interested in whether such flushes will work if I configure the 4-off 2TB drives as a software RAID5 array. Thanks James
