[OmniOS-discuss] [SPAM] Bizarre zfs-related hang in omnios r151008 on 1-CPU VM

[Rob Logan]

> on the latest stable omnios release. When I'm running in VMware Fusion
> on a 1-CPU VM and doing any significant write IO to the pool (e.g. just
>    atomic_dec_32_nv+8()
>    dbuf_read+0x179(ffffff00d2393600, ffffff00c72f98f0, a)
>    dmu_tx_check_ioerr+0x76(ffffff00c72f98f0, ffffff00d2279cf0, 0, 1e0)
>    dmu_tx_count_write+0x395(ffffff00ce0536e0, 3c04000, 4000)
>    dmu_tx_hold_write+0x5a(ffffff00d1a55300, 4009, 3c04000, 4000)
>    zfs_write+0x3e3(ffffff00d09ef540, ffffff00028e7e60, 0,
> ffffff00cd511748, 0)
>    fop_write+0x5b(ffffff00d09ef540, ffffff00028e7e60, 0,
> ffffff00cd511748, 0)
>    write+0x250(1, 440660, 4000)
>    sys_syscall+0x17a()


doing the normal re-write of root in r151008 three times 
into lz4 didn’t have any issues on my 2cpu 2G vbox

root at OmniOS:~# lspci
00:02.0 VGA compatible controller: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter
00:04.0 System peripheral: InnoTek Systemberatung GmbH VirtualBox Guest Service
00:05.0 Multimedia audio controller: Intel Corporation 82801AA AC'97 Audio Controller (rev 01)
00:07.0 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 08)
00:11.0 Ethernet controller: Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) (rev 02)
00:18.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f2)
00:19.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f2)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 02)
00:1f.2 SATA controller: Intel Corporation 82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode] (rev 02)
00:1f.4 USB controller: Apple Inc. KeyLargo/Intrepid USB

root at OmniOS:~# zfs get all | grep refcompressratio
rpool                                refcompressratio              1.00x                                 -
rpool/ROOT                           refcompressratio              1.00x                                 -
rpool/ROOT/start                     refcompressratio              1.85x                                 -
rpool/ROOT/work                      refcompressratio              1.98x                                 -
rpool/ROOT/work at 2013-12-05-19:24:16  refcompressratio              1.85x                                 -

not sure how to reproduce.

			Rob