log并不是写入数据的缓冲,只是校验数据日志的写入缓冲。 metadata没有生产环境的测试,不好判断真实情况。 关于缓冲vdev安全性: 1,cache读缓冲,SSD以条带模式加入池,硬盘损坏,只降低性能,并不影响数据安全。 2,log写缓冲,SSD以镜像模式加入池,硬盘损坏,有数据丢失风险。 3,metadata元数据读写缓冲,SSD以镜像模式加...
选项有“二级动态切换式缓存(L2ARC)”“独立 ZFS 意向暂存(SLOG)”以及“元数据专用分区(Special Metadata VDev)”。L2ARC 对并发读取有益,SLOG 对并发写入有益,但在家庭环境中罕见并发操作;据官方文档,“元数据分区”是和存储池强绑定的,一荣俱荣,一损俱损。最终决定通过 SLOG 试水——毕竟这次硬切换要求从...
5、Metadata 用于创建Fusion Pools的特殊分配类,以提高元数据和小块 i/o 性能。 6、Dedup Dedup vde用于存储ZFS池中的重复删除数据。需要为每X TiB的通用存储分配X GiB。例如,1 GiB的Dedup vdev容量对应1 TiB的Data vdev可用容量。 Vdev布局 根据特定的池用例,添加到vdev中的磁盘以不同的布局排列。不支持将...
硬件上新购入一块PM9A3 3.84TB 2.5" U.2, 将Special/Metadata Vdev从原本的3-Way Mirror变成了...
2、关于VDev类型 每个系统必须建立一个数据存储池,其余存储池可在数据存储池建立完成后添加或删除。 1)数据 用于主存储操作的标准 vdev。每个存储池至少需要一个数据vdev。 2)缓存 读取缓存与快速设备一起使用以加速读取操作。 TrueNAS存储顺序为内存->缓存存储池->数据存储池。
现在lz4和zstd都支持多线程的。比如我现在用的centos 8 stream版本自带的是v1.8.3，当启用压缩时候，...
*This* part of the problem is where a dedicated metadata VDEV *can* really help. Preloading DDT, persistent L2ARC, and other OpenZFS DDT improvements are all being worked on, so we should see a lot happen within a year maybe, or 2 at most? But until they are completed and rolled ou...
I can't figure out if I need to set up redundant mirrored disks for the speical Metadata vdev. If the Metadata vdev is lost with a single drive, will the data vdev still function? Can the Metadata vdev still be rebuilt? Also, what is optimal sizing for a Metadata vdev? Trying to...
A special vdev can store meta data such as file locations and allocation tables. The allocations in the special class are dedicated to specific block types. By default, this includes all metadata, the indirect blocks of user data, and any deduplication tables. The class can also be provision...
fusion pools allow you to introduce mixed tiers of storage of different performance and combine them into a single visible pool, but in the background the system is sending data to the drive media that is best suited to supply it – so metadata on the SSD media, larger bulkier sequential ...