Abstract: A tool for feeding material into a mill having a roller and forming a nip gap. The tool broadly comprises a baseplate, a guide plate, and a ram. The baseplate is configured to be positioned on the mill over the roller and forms a slot. The guide plate is configured to be positioned in the slot of the baseplate near the nip gap. The guide plate forms a chute for feeding the material into the nip gap. The ram is configured to be inserted into the chute to urge the material into the nip gap while preventing a user's fingers and other foreign objects from nearing the nip gap through the chute.

Abstract: A holding system includes a holder. The holder includes a peripheral lip and a flexible collar extending inward and downward from the peripheral lip. The flexible collar defines an opening configured to receive an object. The holding system further includes at least one of (a) a plurality of slide pads having at least a portion thereof positioned along an upper side of the flexible collar or (b) a biasing element extending along and around a periphery of an underside of the flexible collar.

Abstract: A computer-implemented method according to one embodiment includes performing a first process for each chunk of data of each file of a snapshot of a file system. The first process includes reading a given chunk of data of a given file of a first snapshot of the file system, and reading shadow records of a shadow file of the first snapshot. The given chunk of data is compared with the shadow records for determining whether a coherent state exists between the given chunk of data and one or more of the shadow records that were recorded in a snapshot creation window. In response to determining that no coherent state exists, an indication is recorded that the given chunk of data is corrupt. In response to determining that a coherent state exist, an indication is recorded that the given chunk of data is accurate.

Abstract: A computer-implemented method according to one embodiment includes determining a location within a file system that is potentially vulnerable to hardware failures, and injecting one or more simulated hardware failures into the determined location within the file system. The method further includes determining whether the file system was damaged as a result of injecting the simulated hardware failure(s). In response to determining that the injection of the simulated hardware failure(s) resulted in damage to the file system, it is determined whether the damage is repairable. Based on whether the file system was damaged as a result of injecting the simulated hardware failure(s) and/or based on whether or not the damage is determined to be repairable, a tolerance-to-storage-failure score is assigned to the file system.

Abstract: A computer-implemented method according to one embodiment includes determining a location within a file system that is potentially vulnerable to hardware failures, and injecting one or more simulated hardware failures into the determined location within the file system. The method further includes determining whether the file system was damaged as a result of injecting the simulated hardware failure(s). In response to determining that the injection of the simulated hardware failure(s) resulted in damage to the file system, it is determined whether the damage is repairable. Based on whether the file system was damaged as a result of injecting the simulated hardware failure(s) and/or based on whether or not the damage is determined to be repairable, a tolerance-to-storage-failure score is assigned to the file system.

Abstract: A computer-implemented method according to one embodiment includes performing a first process for each chunk of data of each file of a snapshot of a file system. The first process includes reading a given chunk of data of a given file of a first snapshot of the file system, and reading shadow records of a shadow file of the first snapshot. The given chunk of data is compared with the shadow records for determining whether a coherent state exists between the given chunk of data and one or more of the shadow records that were recorded in a snapshot creation window. In response to determining that no coherent state exists, an indication is recorded that the given chunk of data is corrupt. In response to determining that a coherent state exist, an indication is recorded that the given chunk of data is accurate.

Abstract: Embodiments include techniques for metadata verification in a distributed file system, the technique including receiving an input for metadata, the metadata being associated with a file, and acquiring a function lock on a designated region of the file based at least in part on the metadata. The technique also includes hashing the input associated with the metadata into a designated region of the file, and updating the designated region corresponding to the input. The technique includes computing a checksum for the metadata associated with the designated region, updating a journal file based at least in part on the metadata, and releasing the function lock.

Abstract: Embodiments include techniques for metadata verification in a distributed file system, the technique including receiving an input for metadata, the metadata being associated with a file, and acquiring a function lock on a designated region of the file based at least in part on the metadata. The technique also includes hashing the input associated with the metadata into a designated region of the file, and updating the designated region corresponding to the input. The technique includes computing a checksum for the metadata associated with the designated region, updating a journal file based at least in part on the metadata, and releasing the function lock.

Abstract: A lock manager configured for locking files is tested. As part of the test and based on a lock assignment plan, a process acquires locks on portions of the files. Based on a lock testing plan, a second process performs a lock verification for a portion of the locked portions. A result of this lock verification is compared to its expected result. Based on an updated lock assignment plan, the process transitions from the locks to other locks on other portions of the files. Based on an updated lock testing plan, the second process performs a second lock verification for a portion of the other locked portions. A result of this second lock verification is compared to its expected result. Based at least in part on the two comparisons, the lock manager is evaluated.

Abstract: A lock manager configured for locking files is tested. As part of the test and based on a lock assignment plan, a process acquires locks on portions of the files. Based on a lock testing plan, a second process performs a lock verification for a portion of the locked portions. A result of this lock verification is compared to its expected result. Based on an updated lock assignment plan, the process transitions from the locks to other locks on other portions of the files. Based on an updated lock testing plan, the second process performs a second lock verification for a portion of the other locked portions. A result of this second lock verification is compared to its expected result. Based at least in part on the two comparisons, the lock manager is evaluated.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: Embodiments include techniques for metadata verification in a distributed file system, the technique including receiving an input for metadata, the metadata being associated with a file, and acquiring a function lock on a designated region of the file based at least in part on the metadata. The technique also includes hashing the input associated with the metadata into a designated region of the file, and updating the designated region corresponding to the input. The technique includes computing a checksum for the metadata associated with the designated region, updating a journal file based at least in part on the metadata, and releasing the function lock.

Abstract: Embodiments include techniques for metadata verification in a distributed file system, the technique including receiving an input for metadata, the metadata being associated with a file, and acquiring a function lock on a designated region of the file based at least in part on the metadata. The technique also includes hashing the input associated with the metadata into a designated region of the file, and updating the designated region corresponding to the input. The technique includes computing a checksum for the metadata associated with the designated region, updating a journal file based at least in part on the metadata, and releasing the function lock.

Abstract: A lock manager configured for locking files is tested. As part of the test and based on a lock assignment plan, a process acquires locks on portions of the files. Based on a lock testing plan, a second process performs a lock verification for a portion of the locked portions. A result of this lock verification is compared to its expected result. Based on an updated lock assignment plan, the process transitions from the locks to other locks on other portions of the files. Based on an updated lock testing plan, the second process performs a second lock verification for a portion of the other locked portions. A result of this second lock verification is compared to its expected result. Based at least in part on the two comparisons, the lock manager is evaluated.

Abstract: A lock manager configured for locking files is tested. As part of the test and based on a lock assignment plan, a process acquires locks on portions of the files. Based on a lock testing plan, a second process performs a lock verification for a portion of the locked portions. A result of this lock verification is compared to its expected result. Based on an updated lock assignment plan, the process transitions from the locks to other locks on other portions of the files. Based on an updated lock testing plan, the second process performs a second lock verification for a portion of the other locked portions. A result of this second lock verification is compared to its expected result. Based at least in part on the two comparisons, the lock manager is evaluated.

Abstract: A lock manager configured for locking files is tested. As part of the test and based on a lock assignment plan, a process acquires locks on portions of the files. Based on a lock testing plan, a second process performs a lock verification for a portion of the locked portions. A result of this lock verification is compared to its expected result. Based on an updated lock assignment plan, the process transitions from the locks to other locks on other portions of the files. Based on an updated lock testing plan, the second process performs a second lock verification for a portion of the other locked portions. A result of this second lock verification is compared to its expected result. Based at least in part on the two comparisons, the lock manager is evaluated.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.

Abstract: Aspects include testing distributed file systems by selecting a file in a multiple writer environment and selecting an offset of a block in the file. Test data is generated for the block by randomly selecting a starting value from a plurality of possible starting values. A test header that includes the starting value and a test data sequence that starts with the starting value is created. A file system that is being tested writes the test header and the test data sequence to the block. Contents of the block are read by the file system that is being tested, and expected contents of the data sequence are determined based on contents of the read header. The expected contents of the data sequence are compared to the read data sequence and an error indication is output based on the expected contents not being equal to the read contents.