348
349 This feature becomes active when the "zpool remove" command is used
350 on a top-level vdev, and will never return to being enabled.
351
352
353 large_blocks
354
355 GUID org.open-zfs:large_block
356 READ-ONLY COMPATIBLE no
357 DEPENDENCIES extensible_dataset
358
359 The large_block feature allows the record size on a dataset to be
360 set larger than 128KB.
361
362 This feature becomes active once a recordsize property has been set
363 larger than 128KB, and will return to being enabled once all
364 filesystems that have ever had their recordsize larger than 128KB
365 are destroyed.
366
367
368 sha512
369
370 GUID org.illumos:sha512
371 READ-ONLY COMPATIBLE no
372 DEPENDENCIES extensible_dataset
373
374 This feature enables the use of the SHA-512/256 truncated hash
375 algorithm (FIPS 180-4) for checksum and dedup. The native 64-bit
376 arithmetic of SHA-512 provides an approximate 50% performance boost
377 over SHA-256 on 64-bit hardware and is thus a good minimum-change
378 replacement candidate for systems where hash performance is
379 important, but these systems cannot for whatever reason utilize the
380 faster skein and edonr algorithms.
381
382 When the sha512 feature is set to enabled, the administrator can
383 turn on the sha512 checksum on any dataset using the zfs set
384 checksum=sha512 command. This feature becomes active once a
385 checksum property has been set to sha512, and will return to being
386 enabled once all filesystems that have ever had their checksum set
387 to sha512 are destroyed.
441 pre-seeded with a secret 256-bit random key (stored on the pool)
442 before being fed the data block to be checksummed. Thus the
443 produced checksums are unique to a given pool.
444
445 When the edonr feature is set to enabled, the administrator can
446 turn on the edonr checksum on any dataset using the zfs set
447 checksum=edonr command. This feature becomes active once a
448 checksum property has been set to edonr, and will return to being
449 enabled once all filesystems that have ever had their checksum set
450 to edonr are destroyed.
451
452 Booting off of pools using edonr is NOT supported -- any attempt to
453 enable edonr on a root pool will fail with an error.
454
455
456 SEE ALSO
457 zfs(1M), zpool(1M)
458
459
460
461 August 27, 2013 ZPOOL-FEATURES(5)
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348
349 This feature becomes active when the "zpool remove" command is used
350 on a top-level vdev, and will never return to being enabled.
351
352
353 large_blocks
354
355 GUID org.open-zfs:large_block
356 READ-ONLY COMPATIBLE no
357 DEPENDENCIES extensible_dataset
358
359 The large_block feature allows the record size on a dataset to be
360 set larger than 128KB.
361
362 This feature becomes active once a recordsize property has been set
363 larger than 128KB, and will return to being enabled once all
364 filesystems that have ever had their recordsize larger than 128KB
365 are destroyed.
366
367
368
369 vdev_properties
370
371 GUID com.nexenta:vdev_properties
372 READ-ONLY COMPATIBLE yes
373 DEPENDENCIES none
374
375 This feature indicates that the pool includes on-disk format
376 changes that support persistent vdev-specific properties. This
377 feature will be active when the first vdev-specific property is
378 set.
379
380
381
382 cos_properties
383
384 GUID com.nexenta:cos_properties
385 READ-ONLY COMPATIBLE yes
386 DEPENDENCIES com.nexenta:vdev_properties
387
388 This feature indicates that the pool includes on-disk format
389 changes that support persistent Class of Storage (CoS) properties.
390 Such properties can be associated with a collection of device that
391 belong to a common class from storage management standpoint. This
392 feature will be active when the first CoS property is set.
393
394
395
396 meta_devices
397
398 GUID com.nexenta:meta_devices
399 READ-ONLY COMPATIBLE yes
400 DEPENDENCIES none
401
402 This feature flag indicates presence of special-vdev in the pool.
403 Special vdev is used to speed-up read and write operations and can
404 be used to store ZFS metadata and/or write log (ZIL). In addition,
405 special vdev can function as a writeback cache (WBC) within the
406 pool, accelerating ZFS writes via underlying fast media (typically,
407 write-optimized SSD).
408
409 Note that unlike the first two functions the WBC function is
410 configurable on a per-dataset tree basis.
411
412
413
414 wbc
415
416 GUID com.nexenta:wbc
417 READ-ONLY COMPATIBLE no
418 DEPENDENCIES com.nexenta:meta_devices
419
420 When enabled, this feature indicates that the pool supports
421 writeback caching. The latter can be activated on a specific
422 filesystem (and all its children) or a volume (zvol) within the
423 pool by setting the corresponding wbc_mode property to 'on'. This
424 feature will show up as disabled if the pool does not contain
425 special-vdev.
426
427
428
429 sha512
430
431 GUID org.illumos:sha512
432 READ-ONLY COMPATIBLE no
433 DEPENDENCIES extensible_dataset
434
435 This feature enables the use of the SHA-512/256 truncated hash
436 algorithm (FIPS 180-4) for checksum and dedup. The native 64-bit
437 arithmetic of SHA-512 provides an approximate 50% performance boost
438 over SHA-256 on 64-bit hardware and is thus a good minimum-change
439 replacement candidate for systems where hash performance is
440 important, but these systems cannot for whatever reason utilize the
441 faster skein and edonr algorithms.
442
443 When the sha512 feature is set to enabled, the administrator can
444 turn on the sha512 checksum on any dataset using the zfs set
445 checksum=sha512 command. This feature becomes active once a
446 checksum property has been set to sha512, and will return to being
447 enabled once all filesystems that have ever had their checksum set
448 to sha512 are destroyed.
502 pre-seeded with a secret 256-bit random key (stored on the pool)
503 before being fed the data block to be checksummed. Thus the
504 produced checksums are unique to a given pool.
505
506 When the edonr feature is set to enabled, the administrator can
507 turn on the edonr checksum on any dataset using the zfs set
508 checksum=edonr command. This feature becomes active once a
509 checksum property has been set to edonr, and will return to being
510 enabled once all filesystems that have ever had their checksum set
511 to edonr are destroyed.
512
513 Booting off of pools using edonr is NOT supported -- any attempt to
514 enable edonr on a root pool will fail with an error.
515
516
517 SEE ALSO
518 zfs(1M), zpool(1M)
519
520
521
522 March 25, 2016 ZPOOL-FEATURES(5)
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