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6

This setup may not be tuned well. There are parameters needed for both the /etc/modprobe/zfs.conf file and the ashift value when using SSDs Try ashift=12 or 13 and test again. Edit: This is still a virtualized solution, so we don't know too much about the underlying hardware or how everything is interconnected. I don't know that you'll get better ...


4

What they're alluding to here is a configuration where you simply add all the disks to a pool (without a parent mirror or raidz group controlling the disks). In this configuration, the number of devices a file is put on is dictated by the copies attribute, which is controlled by the zfs set command - so some data (by ZFS filesystem) in the pool will have ...


3

Without detailed explanation here is how you can do this. Create an archive of your LXC container. Create a Proxmox Container using that archive as a template. First cd into your lxc container root directory: cd /var/lib/lxc/debian8/rootfs/ (If you used an lvm volume as your containers storage, you need to mount it and cd into your mount point, which ...


3

Solaris 11 ZFS uses NFSv4 ACLs rather than POSIX ACLs. Linux doesn't have NFSv4 ACLs on ZFS at all, and seems like it never will. While NFSv4 ACLs are a superset of POSIX ACLs, seems like only Solaris can transfer/translate POSIX ACLs to NFSv4 ones during file moving/copying. So, concluding, I don't see a way to preserve ACL in ZFS snapshots. Either use ...


3

These paragraphs are misleading and misinformed. Ari has a single disk workstation. She buys a new disk and plugs it in. ZFS automatically adds the new disk space into the pool. ZFS doesn't automatically add a newly inserted disk to a pool. You have to run the zpool command to tell how you want the disk to be used. Her home directory is mirrored ...


3

We were looking into running Mongo on ZFS and saw that this post raised major concerns about the performance available. Two years on we wanted to see how new releases of Mongo that use WiredTiger over mmap, performed on the now officially supported ZFS that comes with the latest Ubuntu Xenial release. In summary it was clear that ZFS doesn't perform quite ...


2

Just now, on ubuntu 16.04 I did sudo find /dev and then created a zvol, and then sudo find /dev again, and then created partitions, and then did a final sudo find /dev to see what was created at each step along the way. What I found was: sudo zfs create -V 8g storage/junkzvol created /dev/zvol/storage/junkzvol sudo fdisk /dev/zvol/storage/junkzvol created /...


2

Some background information: In ZFS you build your storage pools out of vdevs (virtual devices). A single pool can have as many vdevs as you want, and each vdev itself can consist of one or more disks. Redundancy is managed at the vdev level, so your pool will always be striped (concatenated) over all vdevs it consists of. This means you will lose your pool ...


2

It seems likely that you're waiting on a Linux kernel mutex lock that in turn may be waiting on a Xen ring buffer. I can't be certain of this without access to a similar machine, but I'm not interested in paying Amazon $7/hour for that privilege. Longer write-up is here: https://www.reddit.com/r/zfs/comments/4b4r1y/...


2

Not yet. The issue for implementing encryption is here on github for ZFS on Linux. As others have pointed out, you do have the option of LUKS on ZoL. References: oracle docs on zfs encryption


2

I read on the freebsd forums a post which suggested to use zpool online -e <pool> <vdev> (without needing to offline the vdev first) This ultimately was the solution, but it required that ZFS autoexpand be disabled first: [root@timestandstill ~]# zpool list NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT dfbackup 214G ...


2

As you have no common baseline snapshot in your setup, you will not be able to perform an incremental zfs send any longer. You would need to destroy the dataset in backuppool: zfs destroy -r backuppool/x and re-send the most recent snapshot to backuppool zfs send mainpool/x@6 | [transfer magic] | zfs recv backuppool/x The deleting of all your backup ...


2

Why are you passing the disks through a RAID Controller? JBOD would make more sense when using ZFS. You could run into Problems because of your controller. Anyway, its save to just detach and re-attach the disk. You could also try to replace the disk (without really replacing it: zpool replace pool disk) Let it resilver and scrub again.


2

Obviously, you didn't import the pool. Furthermore, I think you don't want to set a mountpoint to / unless you import the pool with -o altroot key.


1

Look at arc_meta_used and arc_meta_limit. With lots of small files you can fill up the meta data cache in ram so it has to look at the disk for file info and can slow the world to a crawl. I'm not sure how to do this on Linux, my experience is on FreeBSD.


1

Given the fact, that the zpool loss took place during a regular reboot, I hoped that at least the zpool export took place. And even if it had been shut down unclean, I prefer to do rescue works on copies. So I added a large HDD to my system (which was added as device sdb - thanks udev) and formatted it with two partitions of the same size as the zfs ...


1

The most simple solution is to periodically flush buffer and pagecache memory. You can do it easily running a similar bash line in the background (or in another tty): while true; do echo 3 > /proc/sys/vm/drop_caches; sleep 5; done UPDATE: as it seems that the above solution does not work as needed, you can try a different way to avoid polluting the buffer/...


1

I'd say yes. My rule is to stay under 87% on SSD-only pools when using drives that haven't been heavily over-provisioned. The SSD use case introduces the drive endurance component, while the random write latency is less of an issue that with spinning disks. Either way, regardless of disk choice, why would you intentionally plan to run your workloads at ...


1

Please make sure the zfs service (target) is enabled. That's what handles pool import/export on boot/shutdown. zfs.target loaded active active ZFS startup target You should never have to struggle with this. If you have a chance, run an update on your zfs distribution, as I know the startups services have improved over the last few releases: [root@...


1

More RAM might be a good option. If read performance is not critical, but metadata operations are: I would recommend setting "primarycache" to "metadata" for your filesystems. If you have SSDs for L2ARC, you can also choose to use memory (ARC) for caching "all" and secondarycache (L2ARC) as "metadata". Please note that the other way around does not work (...


1

EDIT: i first thought it was mirror pool, not raidz. Firstly, zpool replace should work fine. If it is slow because that dying disk is acting slow, you can offline/detach it first so data is rebuilt from other disks and reads are not attempted from the bad disk. Multiple failing disks is not a good thing though. Exporting pool, using ddrescue and then ...


1

I found that I as I had been experimenting with cache settings to see what would happen I had left the primary cache switched off which can result in real IO being far greater than logical IO due to [application] reads a file, gets 4k (pagesize?) of data and processes it, then it reads the next 4k, etc. ZFS, however, cannot read just 4k. It reads ...



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