On Sun, Jun 24, 2012 at 12:48 PM, Stephen John Smoogen <[email protected]> wrote: > On 23 June 2012 11:04, Daryl Herzmann <[email protected]> wrote: >> On Fri, Jun 22, 2012 at 4:03 PM, Stephen John Smoogen <[email protected]> >> wrote: >>> On 22 June 2012 14:10, daryl herzmann <[email protected]> wrote: >>>> Howdy, >>>> >>>> The RHEL6.3 release notes have a curious entry: >>>> >>>> http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.3_Technical_Notes/kernel_issues.html >>>> >>>> kernel component >>>> >>>> Due to a race condition, in certain cases, writes to RAID4/5/6 while the >>>> array is reconstructing could hang the system >>>> >>>> Wow, I am reproducing it frequently here. Simply have a RAID-5 software >>>> array and do some write IO to it, eventually things start hanging and the >>>> power button needs to be pressed. >>>> >>>> Oh man. >>> >>> Well the race condition they are mentioning should only happen when >>> the RAID array is reconstructing. This sounds like a different >>> bug/problem. What kind of disks, type of RAID etc. >> >> Thanks for the response. I am not sure of the difference between >> 'reconstructing' and 'resyncing' and/or 'syncing'. The reproducing >> case was quite easy for me. >> >> 1. Create a software raid5 >> 2. Immediately then create a filesystem on this raid5, while init sync >> underway >> 3. IO to the RAID device eventually stops, even for the software raid5 sync > > Ok reconstructing is where the initial RAID drives pair up with each > other. Resyncing I believe is where a RAID which has been created is > putting the data across its raid. Basic cat /proc/mdstat.. if there is > a line ====> then you are reconstructing the disk array. In the > example you give above, the disks would be reconstructing > > So the next thing to do is why you are able to trigger it constantly. > That may be due to > CPU Type: > RAM Amount: > Disk controllers: > DIsk types (SATA, SAS, SCSI, PATA): > RAID type: > RAID layout (same controller, different controller, etc):
I don't seem to have much issue reproducing, I just had another machine do it this morning. Nehalem processor, 12 GB ram, Dell PowerEdge T400, Perc 6i controller, software raid 5, Seagate 2 TB Barracuda drives... Does anybody have the bugzilla ticket associated with this or perhaps a knowledge base article on it? daryl _______________________________________________ rhelv6-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv6-list
