2015年7月10日 · Since ZFS utilizes algorithms to track frequently used data in addition to recently used data, your cache devices will still provide performance improvements after a backup. ZFS brings frequently and recently used data to the highest performing storage, first to system memory, then to caching devices, allowing for flash media performance ...

2025年2月18日 · One is Adaptive Replacement Cache (ARC), which uses the server memory (RAM). The other is second level adaptive replacement cache (L2ARC), which uses cache drives added to ZFS storage pools. These cache drives are multi-level cell (MLC) SSD drives and, while slower than system memory, are still much faster than standard hard drives.

2021年9月11日 · zfs_arc_max; zfs_arc_sys_free; By default, TrueNAS has zfs_arc_max as 0, which defaults to 50%. zfs_arc_sys_free is interesting because it tells zfs to keep at least this much system memory free. I have combined these successfully since the …

2016年3月4日 · To improve read performance, ZFS utilizes system memory as an Adaptive Replacement Cache (ARC), which stores your file system’s most frequently and recently used data in your system memory. You can then add a Level 2 Adaptive Replacement Cache (L2ARC) to extend the ARC to a dedicated disk (or disks) to dramatically improve read speeds ...

2020年5月5日 · I have a question regarding zfs cache. It's nearly consuming 40Gb of RAM and bringing the system to a crawl. I wasn't aware ZFS cache consumed this much memory. Is there a way to limit the amount of RAM it requires since its basically making the system unusable. I have the following tunable: vfs.zfs.arc_max 61632000000 sysctl Generated by ...

2021年3月9日 · Hi guys-We a large 500 TB pool with 4x 8 TB nvme cache drives. From what I can see with zpool iostat -v, they are barely touched. What optimizations can I do to force more items to be placed into the read cache for faster repeat access? We are mostly storing large photos and videos. Thank you in...

2022年12月8日 · I have a scale 22.02 system with 32G of ram and about 12TB usable space (18TB raw). When I first installed I saw the cache memory usage usually around 15G, which was as expected as half the system memory. I've now created a couple of VMs and I have noticed that the zfs cache is limited to half the system memory minus any memory given to vms.

2014年11月3日 · With write cache enabled (cache flush disabled) I'm getting a bit more than 50,000 KB/s whereas w/o cache (normal ZFS HDD cache flush) I'm getting less than 5,000 KB/s. For the Intel the difference seems a lot smaller and it "only" doubles the write speed w/o cache flushing and the Samsung outperforms the Intel with caching enabled.

2021年10月19日 · ZFS Pool Mirror - 2*Western Black 1To + Cache 1*Corsair GT 120. J. Janus0006 Dabbler. Joined Mar 27, 2021 ...

2021年6月9日 · options zfs l2arc_rebuild_enabled=1 # Persistent L2ARC, is 1 by default so this option shouldn't be necessary. options zfs l2arc_noprefetch=0 # NoPrefetch = False to also cache synchronous reads. options zfs l2arc_write_max=536870912 # Increase the maximum write from 8mb/s to 500mb/s options zfs l2arc_write_boost=1073741824 # At startup it'll ...