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Annotation of wikisrc/users/haad/porting_zfs.mdwn, revision 1.3

1.1       wiki        1: # 1. Status of NetBSD zfs port
                      2:  
                      3: NetBSD zfs port is work in progress and can easily panic your system.
1.2       wiki        4: 
                      5: **ZFS currently works ony on i386!!**
                      6: 
1.1       wiki        7: ---
                      8: # 2. Using NetBSD ZFS port 
                      9: 
1.2       wiki       10: ## Instalation 
1.1       wiki       11: 
1.2       wiki       12: Use any -current build from i386 or amd64 architecture. All tools and modules should be built by default, now. There are 2 modules used for ZFS solaris.kmod and zfs.kmod. Solaris module provides solaris like interfaces to zfs on NetBSD. The second module is zfs and provides zfs file system functions.
1.1       wiki       13: 
                     14: ## Configuration
                     15: 
1.2       wiki       16: User need to
                     17: 
                     18:  modload solaris
                     19:  modload zfs
                     20: 
                     21: After loading modules user can create zpool(zfs version of volume manager) and manage zfs file systems on it. 
                     22: 
1.3     ! wiki       23: zpool create {zpool name} {type} {device} 
1.2       wiki       24: 
1.3     ! wiki       25: where type is:
        !            26: 
        !            27: * mirror
        !            28: * raidz
        !            29: * raidz2
        !            30: * default is normal linear allocation
1.2       wiki       31: 
                     32: device is blod device on netbsd /dev/sd0a for example.
                     33: 
                     34: zpool create tank mirror /dev/sd0a /dev/sd1a  creates mirrored zpool between 2 disk partitions.
                     35: 
1.3     ! wiki       36: With zpool created we can create zfs filesystems or zvols(zfs logical volume disks)
        !            37: 
        !            38: zfs create -V {size} tank/{zvol name} creates zvol with {zvol name} from ZPOOL called tank
        !            39: 
        !            40: Logical disk is created in 
        !            41: 
        !            42: /dev/zvol/rdsk/{zpool name}/{zvol name} 
        !            43: /dev/zvol/dsk/{zpool name}/{zvol name}
        !            44: 
        !            45: zfs create tank/{zfs name} create zfs filesystem on a zpool called tank 
1.2       wiki       46: 
1.1       wiki       47: ## Administration
                     48: 
                     49: ---
                     50: # 3. Known Bugs
                     51: 
                     52: ## Show stoppers 
                     53: 
                     54: ### amd64
                     55: * amd64 zio_root crash
                     56: Investigation 
                     57: vdev_label_read_config -> zio_root calls zio_wait on a zio_root zio_t. Later zio_execute tries to generate                     
                     58: checksum on zio->zio_data which is NULL for a zio_root. Is this ressurrection of andys zio_null problem ? 
                     59: because zio_root is basicaly zio_null.
                     60:                
                     61:  Solution
                     62:  What is difference between i386 and amd64 version why it is working on i386 and not on a amd64 that can be
                     63:  solution.
                     64: ### i386 
                     65: 
                     66: ### Both 
                     67: * vnode reclaiming deadlocks 
                     68:  
                     69:  This can be fixed by deferring call to zfs_zinactive in zfs_reclaim to another system thread if lock is held.
                     70:  But it causes deadlock and we need to investigate if it is caused by this change or by another problem.
                     71:                        
                     72:  Deadlock backtrace is this
                     73:                        
                     74:  VOP_WRITE->zfs_netbsd_write->zfs_write->dmu_tx_wait->txg_wait_open->cv_wait
                     75:  txq_quisce_thread->txg_thread_wait->cv_wait
                     76:  txg_sync_thread->spa_sync->dsl_pool_sync->zio_wait->cv_wait
                     77:                        
                     78:  FreeBSD approach should be investigated why they are doing this differently and why it works for them. They 
                     79:  call zfs_zinactive from zfs_freebsd_inactive which is null op for NetBSD.
                     80:                        
                     81:  zfs umount panic is caused by using FreeBSD approach in zfs_reclaim.
                     82: 
                     83: 
                     84: ## Functional bugs 
                     85: * Snapshots
                     86: * Permissions
                     87: * Old code, we should update NetBSD zfs port to new code