TR Forums

I am a little confused about what space QTS actually uses to store snapshot metadata. And what else unallocated space is needed/used for with Thick/Thin volumes. You can reserve space within the volume provisioning, or - according to my understanding of the documentation - QTS might also start saving this metadata on unallocated portions. I think this is why, when you don't go with a static volume size, QTS is so in-your-face about leaving unallocated space (ie, the threshold warnings, default set at 80% - 20% is a lot to leave on the table). Ideally I would like to have a small 2-3TB volume for personal backup with snapshots giving extra roll-back functionality. Then a large 10TB or so static volume for media, etc. But I'm still uncertain how to properly accomplish this. Right now, it's with two Thick volumes maxed out, with the smaller having internal-volume reserved space for snapshots. But I am worried that the stability of the system will be compromised if I allocated 95%+ of the space (though not sure if this is a valid concern).

Also, with Thick volumes (with preset volume sizes, unlike Thin) why would a Threshold warning even be useful unless QTS is silently filling up unallocated space with metadata, etc?

I will probably just end up going the static volume route after playing around with things for a few more days...

just brew it! wrote:

Usacomp2k3 wrote:

Waco wrote:

I think it's the convenience actually - I bet 90% of consumer drive sales these days are external drives. We're the oddballs.

True. My in-laws have 4, my parents have two. Neither have bought an internal drive ever that wasn’t installed from the OEM.

How does that explain why they are cheaper than internals now, in spite of including a case and power brick?

Exactly, the profit margin on externals is probably much higher than internal drives after factoring in regular warranty claims. The consumer base for externals is huge, and most of these buyers treat them as a consumable to toss and replace when they fail. The warranty length plays into it as well.

I would guess that the ratio of warranty claims made on externals is a fifth of what desktop drives see. At that point $5 for a power brick, $2 of plastic and $1 for the crappy interface board on an external still nets a higher profit margin. People that buy externals and shuck them only exacerbate the difference as those drives will never see a warranty claim either.

Kougar wrote:

I would guess that the ratio of warranty claims made on externals is a fifth of what desktop drives see.

I would expect the opposite. Externals are more likely to get damaged since they're more likely to be physically abused, and the average consumer isn't going to open up their desktop PC to extract an internal drive to RMA it even if it does fail.

just brew it! wrote:

Kougar wrote:

I would guess that the ratio of warranty claims made on externals is a fifth of what desktop drives see.

I would expect the opposite. Externals are more likely to get damaged since they're more likely to be physically abused, and the average consumer isn't going to open up their desktop PC to extract an internal drive to RMA it even if it does fail.

The average consumer (at least, everyone I've ever spoken to about them) chucks the dead drive and simply buys another from a different manufacturer. None of them have ever put a claim in under warranty even when I point out that they can. "Why would I want another one that will break?" is the response I always hear.

Trying to explain that all things fail is moot when they're still angry that their "backup" drive with the one copy of their family pictures died.

Waco, your assessment is spot-on. It's like you overheard my conversations with family members.

This is why I handle backup duties for my family's important stuff. They have their "backups" and I backup those, since they inevitably have one copy of whatever it is ONLY ON THAT EXTERNAL. Drives me nuts.

just brew it! wrote:

I would expect the opposite. Externals are more likely to get damaged since they're more likely to be physically abused, and the average consumer isn't going to open up their desktop PC to extract an internal drive to RMA it even if it does fail.

As Waco said that hasn't been my experience with friends nor family members. Everyone assumes an external has a one year warranty and since none of them bother to track dates they just toss and replace. And yes, because externals see a lot of user or pet-caused damage they are bought far more frequently than drives safely kept inside their computers. Both factors are why I'm willing to bet it's a 5:1 ratio, but you will never find a HDD manufacturer that will spill those secrets and risk such a large, convenient, profitable market.

With 256GB USB flash drives now under $50, the vast majority shouldn't need a true external anymore. I've had family members using them for a few years without much issue. They're easier to use, more durable, less likely to become damaged by pets, cables tangled around feet, etc.

Long-term unpowered data retention/corruption could be another matter, but so far so good.

The Egg wrote:

With 256GB USB flash drives now under $50, the vast majority shouldn't need a true external anymore.

That's still close to an order of magnitude more $/GB than an external HDD. Though I suppose if they aren't backing up a large library of photos/videos 256GB should be plenty.

The Egg wrote:

I've had family members using them for a few years without much issue. They're easier to use, more durable, less likely to become damaged by pets, cables tangled around feet, etc.

Long-term unpowered data retention/corruption could be another matter, but so far so good.

I'd be a little leery of relying on them exclusively, unless they are periodically recopied and protected against bitrot with an additional layer of checksums.

Price per GB isn't a metric used by the Average Joe. Overall cost and ease-of-use are mainly what concerns them, and I'd argue that $/GB is mostly irrelevant at under-$50 anyhow (for small scale quantities). I keep my own backup of the main libraries for family members (updated maybe once a year), so it's really just incremental photos/docs from the past 12 months. We've been doing good with a mix of 16GB and 32GB drives for some time, though 256 would easily be enough for the whole deal. Just as long as they're backing up to something.

Definitely don't keep anything important on unpowered flash. If it's recopied in it's entirety every 6-8 months you're probably okay (and on multiple drives), but USB flash drives are built from the crappiest of the crappy flash that gets scraped off the floor at the fab.

The Egg wrote:

Just as long as they're backing up to something.

If only that meant they wouldn't delete it from the source device.

cynan wrote:

I went with RAID 5 array (though RAID 5 gets a bad name with larger arrays due to single redundancy relative to RAID 6, seems to be a reasonable trade off with 3-drive array). This resulted in about 14.55 TB of usable space (3x8TB drives).

Heh. Late last week, I set up a DS418play with 2ea 10 TB drives. This week, Newegg e-mailed me a deal on a 10 TB drive and the 2x 8GiB DDR3L memory was on sale (to upgrade from the puny 1x 2GiB stock memory), so "why not?" When it arrived, I stuck it in. Storage Manager will let you expand a Synology Hybrid RAID storage pool on-the-fly. At the current rate, it's going to take a while to convert from 2 drives with 1 drive fault tolerance to 3 drives with 1 drive fault tolerance. However, the NAS continues to work without a complaint while it's doing that in the background, so I shouldn't complain that it's taking so long.

P.S.: The expansion operation completed in just over 46 hours. Volume 1 is now 17.46 TiB (19.20 TB) on an 18.18 TiB (19.99 TB) storage pool.

Good stuff JAE. If I weren't determined to keep my FreeNAS server up, Synology is where I'd go.