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...
ZIL is often referred to as a “log” whose main purpose is data integrity. The ZIL exists to track in-progress, synchronous write operations. If the system crashes or loses power, the ZIL can restore the operation or roll it back to the start point. While a standard system cache is lo...
ZIL is often referred to as a “log” whose main purpose is data integrity. The ZIL exists to track in-progress, synchronous write operations. If the system crashes or loses power, the ZIL can restore the operation or roll it back to the start point. While a standard system cache is lo...
You could then use the lines to add the special/cache/log vdevs with the increased ashift - but generally speaking, most devices are optimized for 4K blocks. 8K does provide some increases but might add overhead in terms of consumed space. ajgnet said: And then add the below to put ...
Have you possibly mistaken SLOG for some sort of cache? It isn't. Async writes are ALWAYS faster than sync writes, which are the only time a SLOG device gets used. Adding a SLOG and turning on sync writes always slows the system down, no matter how fast the SLOG. I knew that th...
The same thing when you build pools without redundancy or use differing media interface types outside of a fusion pool or cache setup. It is by no means a perfect solution, but at least TrueNAS have clearly understood that they need to steer things a bit at times....
Add Extra Device button Configure multiple vdevs or add log or cache devices during pool creation. Manual setup button Create a pool manually, which is not recommended. See Manual Setup for more details. Click the Volume name field and enter a name for the pool. Ensure that the chosen name...
8.2.4. Removing Cache or Log Devices Cache or log devices can be removed by going to Storage ➞ Pools. Choose the desired pool and click (Settings) ➞ Status. Choose the log or cache device to remove, then click (Options) ➞ Remove....
If you've got data on the pool already, you can run zdb -LbbbA -U /data/zfs/zpool.cache poolname against it from a command prompt, and sum up the ASIZE column for everything other than the L0 zvol object and L0 ZFS Directory values - look at the bottom of the ou...
zdb -LbbbA -U /data/zfs/zpool.cache <poolname> 最后有个小问题,metadata对于Zvol是无用的。对ZFS来说,往zvol写入多少文件都只是block size大小完全一样的存在,你可以收益到的只是Metadata对Zvol的加速。这个问题的讨论请参考这里。如果你是zvol用的频繁并且还需要更极致的zvol性能,参考章节6.ZFS Send。