File:  [NetBSD Developer Wiki] / wikisrc / users / haad / Attic / porting_zfs.mdwn
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Wed Dec 23 23:37:21 2009 UTC (11 years, 11 months ago) by wiki
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CVS tags: HEAD
web commit by haad

    1: # 1. Status of NetBSD zfs port
    2:  
    3: NetBSD zfs port is work in progress and can easily panic your system.
    4: 
    5: **ZFS currently works ony on i386 and amd64!!**
    6: 
    7: ---
    8: # 2. Using NetBSD ZFS port 
    9: 
   10: ## Instalation 
   11: 
   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.
   13: 
   14: ## Configuration
   15: 
   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: 
   23:     zpool create {zpool name} {type} {device} 
   24: 
   25: where type is:
   26: 
   27: * mirror
   28: * raidz
   29: * raidz2
   30: * default is normal linear allocation
   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: 
   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: 
   44:     /dev/zvol/dsk/{zpool name}/{zvol name}
   45: 
   46:     zfs create tank/{zfs name} create zfs filesystem on a zpool called tank 
   47: 
   48: ## Administration
   49: 
   50: After creating ZVOLS and filesystem they are saved in a /etc/zfs/zpool.cache file and loaded after nextzfs module load.
   51: 
   52: ---
   53: # 3. Known Bugs
   54: 
   55: ## Show stoppers 
   56: 
   57: ### amd64
   58: 
   59: ### i386 
   60: 
   61: ### Both 
   62: * vnode reclaiming deadlocks 
   63:  
   64:  This can be fixed by deferring call to zfs_zinactive in zfs_reclaim to another system thread if lock is held.
   65:  But it causes deadlock and we need to investigate if it is caused by this change or by another problem.
   66: 			
   67:  Deadlock backtrace is this
   68: 			
   69:  VOP_WRITE->zfs_netbsd_write->zfs_write->dmu_tx_wait->txg_wait_open->cv_wait
   70:  txq_quisce_thread->txg_thread_wait->cv_wait
   71:  txg_sync_thread->spa_sync->dsl_pool_sync->zio_wait->cv_wait
   72: 			
   73:  FreeBSD approach should be investigated why they are doing this differently and why it works for them. They 
   74:  call zfs_zinactive from zfs_freebsd_inactive which is null op for NetBSD.
   75: 			
   76:  zfs umount panic is caused by using FreeBSD approach in zfs_reclaim.
   77: 
   78: * vnode fsync bug 
   79:   
   80:   I think that we are hitting this bug, too. I have some patches in the tree which fixes deadlod in vnode reclaim but after that I'm getting another deadlock in VOP_FSYNC.
   81: 
   82: ## Functional bugs 
   83: * Snapshots
   84: * Permissions
   85: * Old code, we should update NetBSD zfs port to new code
   86: * More tasks can be found at <http://nxr.netbsd.org/xref/src/external/cddl/osnet/TODO>
   87: 
   88: # External Documentation links
   89: Nice zfs howto written for zfs + mac os x <http://code.google.com/p/maczfs/wiki/GettingStarted>

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