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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

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. ...


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

ZFS has limited ability to incrementally update a mirrored drive after it has been offline for a while. TL;DR: You can do what you are looking for the way you are suggesting, but it's not what mirrors are meant to do. In practice, what you are suggesting would almost certainly require a full resilver each time, because the interim changes would lead to too ...


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 ...


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

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

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

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

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 ...


1

This doesn't completely remove root login, but it does secure things beyond a full-featured login. Set up an SSH trust by copying the local user's public key (usually ~/.ssh/id_rsa.pub) to the authorized_keys file (~/.ssh/authorized_keys) for the remote user. This eliminates password prompts, and improves security as SSH keys are harder to bruteforce. You ...


1

I came upon the same problem earlier today. I found that you can authorize regular users to do certain operations with the "zfs allow" command: as root, do the following on the server: zfs allow your_username receive,create,mount storage/photos Afterwards, you'll be able to ssh into the server using your_username and you'll have zfs privileges to receive. ...


1

http://code.google.com/p/maczfs/wiki/GettingStarted "Be aware of issues inherent in USB and avoid it wherever possible, or be careful." This is for maczfs, I assume this is also the case is for zfs on other OSs. In other words, yes there seems to be serious drawbacks/risks you're exposed to when using usb drives with zfs.


1

Short answer is no, you can't convert it. You'll need to backup, destroy the mirror, create a raidz and restore the filesystems from backup. ZFS supports adding drives to pools without upsetting the original data but you cannot change the configuration (mirror, raidz, etc.) of existing drives in the pool. In your case you could (although I don't recommend ...


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

Would using ZFS increase performance? Hard to say without knowing your typical disk usage and how you configure your system. For example, how much RAM will you allow ZFS to use? The parity calculations between RAID-Z1 and RAID 5 would probably have similar overheads. Would it be a safer option for my data with equal parity? If you mean a mirror, then ...


1

Depending on how long was you pool kept online after the mistake and also how busy was the pool during this period, it might be possible to rollback it to a previous transaction group (i.e. use an older uberblock) where the file system was still present. Here is a script that takes that approach: ...


1

Are those 4k drives? Yes, you can see that they report 4096 byte physical which is the indicator for this. The 512 byte logical reporting is a result of drive manufacturers' attempt at backwards compatibility (and thus confuses things). gpart? In your situation I would use the following commands to gpart out the disk: # -- Force ashift to be at least 12 ...


1

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, ...


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 ...



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