> On Jul 2, 2019, at 5:48 AM, nagy.att...@gmail.com wrote: > > Glad to hear that! :) > I'll try to be more verbose then. > For example I have a machine with 44*4T SATA disks. Each of these disks have > a zpool on them, so I have 44 zpools on the machine (with one zfs on each > zpool). > I put files onto these zfs/zpools into hashed directories. > On file numbers/sizes: one of the zpools currently have: > 75,504,450 files and df says it has 2.2TiB used, so here the average file > size is 31k. > File serving is done on HTTP. > Nothing special happens here on the ZFS side, the only difference is that I > have single disk zpools. > > And that's why I have some questions on this, I couldn't really find > literature on this topic. > > My biggest issue now is just the import of these zpools consume 50+ GiB > kernel memory (out of 64 on this machine), before anything could touch the > disks (so it's not ARC). And these seem to be something which is/could not > shrunk by the kernel (like the ARC, which can dynamically change its size).
This is strange. What does free(1) say about the distribution of memory? -- richard > Therefore if ARC or other kernel (memory) users consume more memory, it > quickly turns into a deadlock, the kernel starts to kill userspace processes > to the point where it becomes unusable. > > And here come the questions in the original post, from which I'm trying to > understand what happens here, why importing a 4T zpool (with the above fill > ratios) takes 1-1.5GiB kernel space. > And is it because of the files on it (so if I would have a 44x that size > zpool it would be the same, which I couldn't observe on other machines which > have only one zpool) or some kind of per zpool overhead (and if so, what > affects that, what could I do to lower that need)? > > openzfs <https://openzfs.topicbox.com/latest> / openzfs-developer / see > discussions <https://openzfs.topicbox.com/groups/developer> + participants > <https://openzfs.topicbox.com/groups/developer/members> + delivery options > <https://openzfs.topicbox.com/groups/developer/subscription>Permalink > <https://openzfs.topicbox.com/groups/developer/T10533b84f9e1cfc5-M88acd75da161566dc676d3ef> ------------------------------------------ openzfs: openzfs-developer Permalink: https://openzfs.topicbox.com/groups/developer/T10533b84f9e1cfc5-M3364c2e4eb10be9b68bc1580 Delivery options: https://openzfs.topicbox.com/groups/developer/subscription
