> On 20 Feb 2015, at 11:14, Bob Bishop <rb at gid.co.uk> wrote: > > Hi, > >> On 20 Feb 2015, at 10:34, Dr Josef Karthauser <joe at tao.org.uk> wrote: >> >> Hi there, >> >> I reported this last year, but I?d like to revisit it as it must have a software remedy. I know that I?m not the only one to have reported the problem. >> >> I have a ZFS pool with a number of western digital drives in it (WDC WD1000FYPS-01ZKB0 02.01B01). > > WD Green Power drives. I've had similar problems, sometimes they take a looooong time to come ready; the controller times out waiting for drive ready and the rest you know. > > Depending on the controller there may be nothing you can do. Maybe it's possible to turn off the drives's green features. I replaced the drives with something that works. >Hi Bob, In this case other report no such issues on the same hardware running Linux, so it seems to me to be an internal timeout issue within FreeBSD, or maybe Linux retries more than FreeBSD and so doesn?t experience the issue that we do. It?s clear that FreeBSD is proactively disconnecting the drive when the timeout occurs. So, maybe there?s something that can be done there. Joe
On 02/20/15 12:21, Dr Josef Karthauser wrote:> In this case other report no such issues on the same hardware running Linux, so it seems to me to be an internal timeout issue within FreeBSD, or maybe Linux retries more than FreeBSD and so doesn?t experience the issue that we do. It?s clear that FreeBSD is proactively disconnecting the drive when the timeout occurs. So, maybe there?s something that can be done there.Hello. While I cannot disagree with this last sentence, I've had my share of troubles with WD Green drives too. I had to replace them more than once during their warranty period, and was almost happy when they finally broke after the warranty was over. Leaving that aside, these drives will power down if not used for a while, but there is a DOS utility which can disable this feature. Not only this will avoid an even shorter lifespan, but it's an essential procedure if you want to use them with FreeBSD. If you haven't done this, then do it. After doing that, I was able to use them with some controllers, but not others, so YMMV. Finally, upgrading from 7.x to 8.x and then 9.x helped a lot, but in your case I don't know if there is any improvement after 9.2. HTH. bye av.
On Fri, Feb 20, 2015 at 11:21 AM, Dr Josef Karthauser <joe at tao.org.uk> wrote:> In this case other report no such issues on the same hardware running Linux, so it seems to me to be an internal timeout issue within FreeBSD, or maybe Linux retries more than FreeBSD and so doesn?t experience the issue that we do. It?s clear that FreeBSD is proactively disconnecting the drive when the timeout occurs. So, maybe there?s something that can be done there.Linux has more automatic quirks for troublesome hardware, it may also have a longer default timeout. FreeBSD's WD green drives are green, they spin down frequently if idle. If you then try and use them, they can take considerably longer than the timeout to spin back up and be ready, and the kernel gives up. You can make the WD green drives less green by using a dos tool, wdidle3.exe. Google will tell you more (and show that WD green drives cause people problems on all OS when they use them in RAID). The continual parking/unparking considerably reduces the life of disk. You can tell BSD to wait longer with a higher "kern.cam.ada.default_timeout". Cheers Tom
Hi,> On 20 Feb 2015, at 11:21, Dr Josef Karthauser <joe at tao.org.uk> wrote: > > >> On 20 Feb 2015, at 11:14, Bob Bishop <rb at gid.co.uk> wrote: >> >> Hi, >> >>> On 20 Feb 2015, at 10:34, Dr Josef Karthauser <joe at tao.org.uk> wrote: >>> >>> Hi there, >>> >>> I reported this last year, but I?d like to revisit it as it must have a software remedy. I know that I?m not the only one to have reported the problem. >>> >>> I have a ZFS pool with a number of western digital drives in it (WDC WD1000FYPS-01ZKB0 02.01B01). >> >> WD Green Power drives. I've had similar problems, sometimes they take a looooong time to come ready; the controller times out waiting for drive ready and the rest you know. >> >> Depending on the controller there may be nothing you can do. Maybe it's possible to turn off the drives's green features. I replaced the drives with something that works. >> > > Hi Bob, > > In this case other report no such issues on the same hardware running Linux, so it seems to me to be an internal timeout issue within FreeBSD, or maybe Linux retries more than FreeBSD and so doesn?t experience the issue that we do. It?s clear that FreeBSD is proactively disconnecting the drive when the timeout occurs. So, maybe there?s something that can be done there.It depends on the disk controller hardware/firmware (not the drive electronics), not necessarily the driver. From the drive datasheet http://www.wdc.com/en/library/sata/2879-701236.pdf?wdc_lang=en "WD GreenPower drives monitor work load and automatically invoke idle mode whenever possible to further reduce unnecessary power consumption. Drive recovery time from idle mode is less than one second, [etc]" What happens is that the drive decides to idle and the controller has no way of telling. So when the controller issues its next command, the drive takes the best part of a second (if you are unlucky) to come out of idle, execute the command and return to ready. The controller times this out at a very low level and assumes that the drive has gone away. Maybe Linux does the equivalent of a bus rescan to work around this. I had the problem using a dumb RAID 1 controller, once a drive dropped out the mirror was broken so it was a big deal.> Joe-- Bob Bishop rb at gid.co.uk