I’m tired of Windows 7 complaining every time it boots about the Bluetooth radio not being discoverable. The irony is that the Bluetooth settings dialog recommends that you turn off discoverability (for obvious reasons), but when you do, it will bitch and bitch and bitch until you turn it back on. Does anyone know how to make it stop nagging?
Tag: tech
ZFS-to-ZFS backups
ZFS has a couple of very useful functions, zfs send and zfs receive, which allow you to serialize a complete ZFS dataset and recreate it in a different location. They can also be used to serialize a delta between two snapshots and apply that delta to a previously created copy of the dataset. You see where I’m going with this… That’s right, incremental backups of a ZFS dataset or even an entire pool to a different ZFS dataset or pool. Continue reading “ZFS-to-ZFS backups”
More Advanced Format drives: Samsung SpinPoint F4 EcoGreen and Seagate Barracuda Green
I’ve acquired a couple more 2 TB Advanced Format drives: a Seagate Barracuda Green (ST2000DL003) and a Samsung SpinPoint F4 EcoGreen (HD204UI, no data sheet available online). Continue reading “More Advanced Format drives: Samsung SpinPoint F4 EcoGreen and Seagate Barracuda Green”
OpenBSD IPSec backdoor allegations: update
I’m sure I don’t need to remind anyone what this is about…
The latest news: Theo now says that it is probable that NetSec was indeed contracted to insert backdoor code into OpenBSD, but after a month of review and changelog archeology, there is still no sign that they succeeded or even attempted to push tainted code into the tree.
The audit (which is still ongoing) did uncover one serious bug, but there is no reason to believe that it was planted deliberately. This relates to CBC mode, an encryption protocol in which each block of plaintext is combined with the ciphertext of the previous block before encryption to make it harder to attack ciphertext blocks individually. Continue reading “OpenBSD IPSec backdoor allegations: update”
4k drive update
Just to let you know what the current status is wrt. 4k drives:
It looks like the consensus in the industry (meaning everyone except Western Digital) is to announce dual sector sizes, i.e. 512-byte logical sectors on top of 4096-byte physical sectors.
Ivan Voras has taken the initiative to organize a 4k BoF at BSDCan, although judging from the (private) email exchange on the subject, it’s quite possible that a decision will be made before then. Currently, it looks like we’re moving towards having the low-level driver report a 512-byte sector size and 4096-byte stripe width (and, if necessary, an appropriate offset) to GEOM. This preserves backward compatibility, but announces to GEOM consumers that it is a good idea to do I/O in 4096-byte blocks and align data structures on 4096-byte boundaries. All that remains is then to make sure that those GEOM consumers we care about (particularly ZFS) take advantage of this information.
The situation for WD “Advanced Format” drives is a bit more complex, because they announce 512-byte logical sectors. The only solution I can see is to add a quirk system to the ada driver (and possibly to ata as well, if we still care about it) similar to the ones we have for SCSI and USB devices, and match the model number. I believe /WD\d+[A-Z]+RS/ should match all existing Advanced Format drives with no false positives.