Thanks for reply. The problem occurs with my physical hardware and in virtual machine (can't set TLER). The log you see in my original post is captured/simulated from a virtual machine. The system is not 'hung '. If I run rd.debug it would have lots of messages scrolling quickly that you can't see clearly. What I am asking for is a more descriptive message from the MD raid, try to display the status like: Try to activate md/raid1:md125, currently 1 of of 2 disk online. Timeout in X seconds. Something like that. Thanks, Patrick On Tue, Mar 24, 2020 at 2:14 AM Roger Heflin <rogerheflin@xxxxxxxxx> wrote: > > The system had hung. The disks are failing inside the SCSI subsystem, > I don't believe (raid, lvm, multipath) will know anything about what > is going on inside the scsi layer. > > Those default timeouts are usually at least 30 seconds, but in the > past the scsi subsystem did some retrying internally. The timeout > needs to be higher than the length of time the disk could take. > Non-enterprise, non-raid disks generally have this timeout set 60-120 > seconds hence MD waiting to see if the failure is a sector read > failure (will be a no-response until the disk timeout) or a complete > disk failure (no response ever). > > cat /sys/block/sda/device/timeout shows the timeout. > > Read about seterc, tler and smartctl for discussions about what is going on. > > If you can then turn down your disks max timeout with the smartctl > commands then the disk will report back a sector failure faster and > that is usually what is happening. If you turn down the disks timeout > to a max of say 7 seconds then you can set the scsi layers timeout to > say 10 seconds. Then the only time the scsi timeout matters if if > the disk is there but not responding. > > > On Fri, Mar 20, 2020 at 11:50 AM Patrick Dung <patdung100@xxxxxxxxx> wrote: > > > > Hello, > > > > Bump. > > > > Got a reply from Fedora support but asking me to find upstream. > > https://bugzilla.redhat.com/show_bug.cgi?id=1794139 > > > > Thanks, > > Patrick > > > > On Thu, Mar 5, 2020 at 10:57 PM Patrick Dung <patdung100@xxxxxxxxx> wrote: > > > > > > Hello, > > > > > > The system have Linux software raid (md) raid 1. > > > One of the disk is missing or have problem. > > > > > > The raid is degraded. > > > When the OS boot, it hangs at the message for outputting to kernel at > > > about three seconds. > > > There is no descriptive message that the RAID is degraded. > > > I know the problem because I had wrote zero to one of the disk of the > > > raid 1. If I don't know the problem (maybe cable is loose or disk > > > failure), it is confusing. > > > > > > Related log: > > > > > > [ 2.917387] sd 32:0:0:0: [sda] 56623104 512-byte logical blocks: > > > (29.0 GB/27.0 GiB) > > > [ 2.917446] sd 32:0:1:0: [sdb] 56623104 512-byte logical blocks: > > > (29.0 GB/27.0 GiB) > > > [ 2.917499] sd 32:0:0:0: [sda] Write Protect is off > > > [ 2.917516] sd 32:0:0:0: [sda] Mode Sense: 61 00 00 00 > > > [ 2.917557] sd 32:0:1:0: [sdb] Write Protect is off > > > [ 2.917575] sd 32:0:1:0: [sdb] Mode Sense: 61 00 00 00 > > > [ 2.917615] sd 32:0:0:0: [sda] Cache data unavailable > > > [ 2.917636] sd 32:0:0:0: [sda] Assuming drive cache: write through > > > [ 2.917661] sd 32:0:1:0: [sdb] Cache data unavailable > > > [ 2.917677] sd 32:0:1:0: [sdb] Assuming drive cache: write through > > > [ 2.927076] sd 32:0:0:0: [sda] Attached SCSI disk > > > [ 2.927458] sdb: sdb1 sdb2 sdb3 sdb4 > > > [ 2.929018] sd 32:0:1:0: [sdb] Attached SCSI disk > > > [ 3.060855] vmxnet3 0000:0b:00.0 ens192: intr type 3, mode 0, 3 > > > vectors allocated > > > [ 3.061826] vmxnet3 0000:0b:00.0 ens192: NIC Link is Up 10000 Mbps > > > [ 139.411464] md/raid1:md125: active with 1 out of 2 mirrors > > > [ 139.412176] md125: detected capacity change from 0 to 1073676288 > > > [ 139.433441] md/raid1:md126: active with 1 out of 2 mirrors > > > [ 139.434182] md126: detected capacity change from 0 to 314507264 > > > [ 139.436894] md126: > > > [ 139.455511] md/raid1:md127: active with 1 out of 2 mirrors > > > [ 139.456739] md127: detected capacity change from 0 to 27582726144 > > > > > > So there are about 130 seconds without any descriptive messages. I > > > thought the system had hanged. > > > > > > Could the kernel display more descriptive messages about the RAID? > > > > > > If I use rd.debug boot parameters, I know the kernel is still running. > > > But it is scrolling very fast without actually knowing what is the the > > > problem. > > > > > > Thanks, > > > Patrick
