GEOM

这篇和较早的 线上重做 FreeBSD GPT 引导分区 情况有些类似，但略有不同。

前段时间 Andriy Gapon 为 Samsung 860 / 870 SSD 增加了一个 quirk。Samsung 的 SSD 内部使用的是 8K 或 16K 的存储页，但为了和业界标准兼容，它的控制器为 4K 扇区做了优化。

大扇区（超过旧式标准的512字节扇区）是改善硬件工艺或访问方式以后的一种直接提高存储密度的方法。对于磁介质来说，其盘片被分成若干的磁道（通常是同心圆）、每个磁道分成若干的扇区或称扇段，扇区是磁盘读写时的最小操作单元。对于基于闪存的存储设备而言，扇区则是一种模拟传统磁盘的概念。

一直有人抱怨FreeBSD的bsdlabel(8)和fdisk(8)不好用，而进一遍sysinstall又太过麻烦，因此这次有人把磁盘编辑器从sysinstall(8)里面拆了出来，作了一些修改使其成为了一个新的工具——sade(8)。

gjournal is one of the Google Summer of Code projects that is FreeBSD related. It provides data journalling service that will be useful for frequent randomized area writing, just like write clustering.

Today, the first public alpha version has been released.

Please note that this is not intentional to replace SoftUpdates nor a real journalling file system, as the metadata consistency protection is different than just do data writing journalling. However, this indicates a good way of providing better performance for file systems.

Historically, the only translation performed on I/O requests after they they left the file-system layer were logical sub disk implementation done in the device driver. No universal standard for how sub disks are configured and implemented exists, in fact pretty much every single platform and operating system have done it their own way. As FreeBSD migrates to other platforms it needs to understand these local conventions to be able to co-exist with other operating systems on the same disk.