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16

First off: I'm not going to speculate about development 6-7 years into the future. This is about today, and the nearest future. For the TL;DR, see the bottom of this answer. ZFS today does not allow you to remove a vdev from a pool. It also does not have any native "rebalance" functionality (search for block-pointer rewrite, bp rewrite or bpo rewrite to ...


4

In this case I would go to /tank/home/.zfs/snapshot/snapshot_week_01 and pull out the data you need. See Displaying and Accessing ZFS Snapshots on Oracle's website for details.


4

The only reason you would need to use that ratio of RAM to storage space, would be if you decided to use data deduplication. It does not say that the 1 GB to 1 TB ratio is a requirement. According to a wiki: Effective use of deduplication may require large RAM capacity; recommendations range between 1 and 5 GB of RAM for every TB of storage. ...


3

Is a RAID1 (mirror) with 2 x 4TB drives and ZFS (through freenas) okay? If you want to use HW or non-ZFS software RAID with ZFS on top then please choose one of them. Using both would be needlessly complex without advantages. Normally when using larger drives and not just wanting mirroring (read, RAID5[Z1] or 6[Z2]), you have to worry about the size ...


3

ZFS is not a replacement for a good backup. That being stated ZFS is awesome and to me dual disk ZFS in either raidz2 or better yet a stripe of mirrored vdevs, provided you had another copy (preferably another ZFS box) on another machine, preferably offsite would be sufficient. Tape does have its place as well and super long term is definitely among them and ...


3

The command line you found provides a reasonable starting point. I run rsync for backups (through rsnapshot, which isn't really relevant because you will be using ZFS snapshots for history; I started using that before I started using ZFS, and have kept using it because it works well for me) with this set of parameters: -aAHX --delete --numeric-ids --...


2

If there are no remapped or pending sectors, your disk does not know about any defective sectors. It’s more likely that some other component involved in disk access is damaged, like the head or whatever. That being said, I’m with the unRAID wiki on this: PLEASE completely ignore the RAW_VALUE number! Only Seagates report the raw value, which yes, does ...


2

BTRFS RAID-6 is (though still experimental) actually pretty stable now. The current version even manages to fix many typical errors, including replacing a failed/missing drive. Like ZFS, BTRFS does checksumming, which means that you can always (and you should, periodically) run a scrub to verify your data. If data (data or metadata) on a drive is damaged, ...


2

Don't the forget the non-zero risk of fire, theft, natural disasters, etc. Take a serious look at cloud backup services. There's a number of them that offer unlimited backup space (be sure to read the fine print to understand exactly what "unlimited" means though) for under $100 per year. Compared to $2400 for a tape unit plus media, this could be an ...


2

At least ZFS On Linux, which given the tags on the question is probably what you are referring to, does not support your proposed usage at present. As I have discussed elsewhere, ZFS does not support removing constituent devices from a striped set. The pool itself is a striped set of one or more vdevs, where the vdevs may be single device, mirror sets or ...


2

To answer the question "Is it possible", the answer is no. ZFS snapshots have no concept of files, folders, or anything else, it is a block level snapshot of the entire filesystem. You can however browse a snapshot and access individual files, as indicated in duenni's answer, or you can clone a snapshot giving you a second copy of the filesystem without ...


2

ZFS and BTRFS offer protection from bitrot, you have to choose between the two. you also want deduplication for ZFS you will need more RAM for BTRFS you can use batch deduplication https://btrfs.wiki.kernel.org/index.php/Deduplication (in-line dedup is planned) my suggestion is ZFS for encryption i suggest ZFS on top of LUKS ,ZVOL for VMs it is ...


2

Because of its on-disk format (specifically the Merkle tree of checksums), ZFS is relatively write-happy. Regular 10 MB writes with very limited data updates seems a little write-heavy, but not truly extraordinarily so. The one thing I can think of that would be exacerbating this is if you have atime updates turned on. Check the output of zfs get atime pool/...


2

Given that you just want to "play around" with ZFS, the easiest option is probably a file-backed pool. An alternative would be creating one or more logical volumes inside the LVM and use those. One of the beauties of ZFS is that you can give it just about anything that can store data in a random I/O capable form, and it will "just work". In production ...


1

I actually asked this in the #freenas IRC channel, and they were able to answer my question. To answer my own question: no, you cannot add an additional drive to a RAID-Z1 array to make it into a RAID-Z2 array. The nor can you add additional drives to scale the array horizontally. The geometry of the array is set when you first build it. You can however, ...


1

RAID-Z2 works by taking the drives given to the vdev, and using two of those to store redundant data for recovery purposes in case something goes wrong. Hence, the absolute minimum number of drives in a RAID-Z2 vdev is the two redundant ones plus one, which works out to three drives. However, by doing it that way, you: are getting the effective storage ...


1

Well, you've looked at the code, which does use readdir, which doesn't guarantee the order that entries are read out in. But that last doesn't matter. ZFS doesn't care if the device node is referred to in one way or another. What it does care about is whether the on-disk data is accessible through it or not. And if it's not, then that particular directory ...


1

if you choose the ZFS setup,i would suggest: do not use LVM,create ZVOLs on top of pool for OS - GPT partition for unencrypted ZFS pool with mirror(or raidz) for private data - use LUKS on GPT partition , then on top build a ZFS pool mirror(or raidz) after boot you login via ssh ,enter password for encrypted partitons,and import the pool which is on top ...


1

First of all: Before disconnecting or shutting down, you should export “external” pools. When you import them again, the current set of device names will be used. If you want to import a pool using “predictable device names”, you can use the method outlined in Arch Linux’ ZFS Installation Guide: zpool import -d /dev/disk/by-id <poolname> The ...


1

The answer to the question as asked is no; snapshots are per file system and you can only operate on the whole file system when working with the snapshot. So if you roll back to a previous snapshot, that affects the entire file system. The way to restore specific files or directories from a ZFS snapshot is to navigate into the snapshot directory and then ...


1

I'm about to do this and found an old blog that indicates that it can be done. The idea is to: Break the existing mirror by removing one of the existing disks Create a sparse file and mount it as a loopback device Create the new Raid-Z1 using the new disk, the one just removed and the sparse file Immediately degrade the raid by removing the sparse file ...


1

Turns out you can't create with ashift=12 in zfs-fuse: # zpool create -n -o ashift=12 test /dev/disk/by-id/scsi-SATA_...... property 'ashift' is not a valid pool property But it works with the one from github zfs+spl 0.6.5.x: # dd if=/dev/zero of=/tmp/testfile bs=1M count=64 # zpool create -o ashift=12 test /tmp/testfile # dd if=/dev/zero of=/tmp/...



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