What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?
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@anthonyh said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
This would be a bit more work to set up initially as it would probably mean moving away from FreeNAS, but might be worth considering. Of course, you'd need somewhere to stage your 200TB of data which would be a huge feat in itself. But, jussst in case you might be in the market to build a new box....
I've been considering XFS + duperemove (https://github.com/markfasheh/duperemove) for some of my storage needs.
Duperemove is a simple tool for finding duplicated extents and submitting them for deduplication. When given a list of files it will hash their contents on a block by block basis and compare those hashes to each other, finding and categorizing blocks that match each other. When given the -d option, duperemove will submit those extents for deduplication using the Linux kernel extent-same ioctl.
Duperemove can store the hashes it computes in a 'hashfile'. If given an existing hashfile, duperemove will only compute hashes for those files which have changed since the last run. Thus you can run duperemove repeatedly on your data as it changes, without having to re-checksum unchanged data.
What's nice about duperemove is that it's an "out of band" process so to speak. So you can run it during off-peak utilization and start/stop the process at will. It doesn't require RAM like ZFS.
Very nice. I need to play with that.
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@dafyre said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@anthonyh said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@dafyre said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@anthonyh said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
This would be a bit more work to set up initially as it would probably mean moving away from FreeNAS, but might be worth considering. Of course, you'd need somewhere to stage your 200TB of data which would be a huge feat in itself. But, jussst in case you might be in the market to build a new box....
I've been considering XFS + duperemove (https://github.com/markfasheh/duperemove) for some of my storage needs.
Duperemove is a simple tool for finding duplicated extents and submitting them for deduplication. When given a list of files it will hash their contents on a block by block basis and compare those hashes to each other, finding and categorizing blocks that match each other. When given the -d option, duperemove will submit those extents for deduplication using the Linux kernel extent-same ioctl.
Duperemove can store the hashes it computes in a 'hashfile'. If given an existing hashfile, duperemove will only compute hashes for those files which have changed since the last run. Thus you can run duperemove repeatedly on your data as it changes, without having to re-checksum unchanged data.
What's nice about duperemove is that it's an "out of band" process so to speak. So you can run it during off-peak utilization and start/stop the process at will. It doesn't require RAM like ZFS.
Is that an XFS only thing -- or can it work with other File Systems?
Edit: Quick glance at their Github doesn't say anything about which filesystems are required.
If my understanding is correct, this would work with filesystems that support reflinks.
I wonder if this would work for the OP's use case. I think he's on FreeNas though.
I don't think so since FreeNAS uses ZFS exclusively (according to my quick Google search...I am not a FreeNAS user).
I believe OP would need to build a NAS using software that'll support a filesystem with reflinks support.
Though it looks like ZFS on BSD (which IIRC FreeNAS is based on FreeBSD) might support reflinks...
So I really don't know!
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@anthonyh said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
Though it looks like ZFS on BSD (which IIRC FreeNAS is based on FreeBSD) might support reflinks...
Yes, FreeNAS is just an older version of FreeBSD (not very old, just a little.)
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More on reflinks.
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ZFS does not have reflinks, and doesn't plan to. It's a BtrFS feature back ported to XFS on Linux.
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@scottalanmiller said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
ZFS does not have reflinks, and doesn't plan to. It's a BtrFS feature back ported to XFS on Linux.
That's what I thought, but I didn't have the data to back it up.
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ZFS has a lot of similar stuff built in, I don't think that they want to do it two ways. It's not often that people want the extra reflinks functionality.
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@strongbad said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
ZFS has a lot of similar stuff built in, I don't think that they want to do it two ways. It's not often that people want the extra reflinks functionality.
Yeah. ZFS's deduplication functionality is good...just resource intensive. I've talked to guys who build out large storage arrays using ZFS and deduplication and it gets complicated (at least from my ZFS novice point of view) if you want it to perform well.
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@anthonyh said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@strongbad said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
ZFS has a lot of similar stuff built in, I don't think that they want to do it two ways. It's not often that people want the extra reflinks functionality.
Yeah. ZFS's deduplication functionality is good...just resource intensive. I've talked to guys who build out large storage arrays using ZFS and deduplication and it gets complicated (at least from my ZFS novice point of view) if you want it to perform well.
ZFS was never built for performance (Sun said this directly.) It was for low cost, giant scale with good reliability and durability. So that it doesn't handle performance great while doing a feature like dedupe is not at all surprising.
It's also 13 years old and the granddaddy of its type of product.
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@scottalanmiller said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@tim_g said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@scottalanmiller said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
@dbeato would need 256GB of RAM to attempt that with ZFS. That's a lot of RAM on a NAS.
How did you get 256GB of RAM needed?
That FreeNAS article recommends 5GB RAM per 1 TB of deduped data...
Considering he has 200TB of data he'd want to dedup, that's at least 1TB of RAM to start.This is because dedup on ZFS/FreeNAS is much more RAM intensive than all other file systems. (and also because 200TB is a ton of data)
What caused it to balloon so much recently? Traditionally it has been 1GB per 1TB.
Freebsd zfs page stated up to 5gb per 1tb last time I checked
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The starwind dedup estimator can be a thing here?!
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@scottalanmiller said in What's the Best Way to Deduplicate & Organize Files/Folders on a 200 TB NAS?:
More on reflinks.
It's already in Fedora. You don't need the sources any longer.
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Here's using duperemove. It's annoyingly verbose so I can't get the output and the command in the same screenshot.
I ran
/tmp/duperemove/duperemove -hdr --hashfile=tmp/stuff.hash /mntAnd got
