FreeBSD Manual Pages
ZHACK(1) General Commands Manual ZHACK(1) NAME zhack -- libzpool debugging tool DESCRIPTION This utility pokes configuration changes directly into a ZFS pool, which is dangerous and can cause data corruption. SYNOPSIS zhack feature stat pool List feature flags. zhack feature enable [-d description] [-r] pool guid Add a new feature to pool that is uniquely identified by guid, which is specified in the same form as a zfs(8) user property. The description is a short human readable explanation of the new feature. The -r flag indicates that pool can be safely opened in read- only mode by a system that does not understand the guid fea- ture. zhack feature ref [-d|-m] pool guid Increment the reference count of the guid feature in pool. The -d flag decrements the reference count of the guid feature in pool instead. The -m flag indicates that the guid feature is now required to read the pool MOS. zhack label repair [-cu] device Repair labels of a specified device according to options. Flags may be combined to do their functions simultaneously. The -c flag repairs corrupted label checksums The -u flag restores the label on a detached device Example: zhack label repair -cu device Fix checksums and undetach a device GLOBAL OPTIONS The following can be passed to all zhack invocations before any subcom- mand: -c cachefile Read pool configuration from the cachefile, which is /etc/zfs/zpool.cache by default. -d dir Search for pool members in dir. Can be specified more than once. EXAMPLES # zhack feature stat tank for_read_obj: org.illumos:lz4_compress = 0 for_write_obj: com.delphix:async_destroy = 0 com.delphix:empty_bpobj = 0 descriptions_obj: com.delphix:async_destroy = Destroy filesystems asynchronously. com.delphix:empty_bpobj = Snapshots use less space. org.illumos:lz4_compress = LZ4 compression algorithm support. # zhack feature enable -d 'Predict future disk failures.' tank com.example:clairvoyance # zhack feature ref tank com.example:clairvoyance SEE ALSO ztest(1), zpool-features(7), zfs(8) FreeBSD Ports 14.quarterly May 26, 2021 ZHACK(1)
NAME | DESCRIPTION | SYNOPSIS | GLOBAL OPTIONS | EXAMPLES | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=zhack&sektion=1&manpath=FreeBSD+Ports+14.3.quarterly>