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Comment: Re:It DOES have permission (Score 4, Insightful) 224

by m.dillon (#48475327) Attached to: Uber's Android App Caught Reporting Data Back Without Permission

No, in fact the vast majority of people who run an IOS app on an Apple device who see a permission request pop up that they don't like, say 'No', and the app continues to run just fine.

Even better, the apps on IOS tend not to request absurd permissions in the first place because they know those pop-ups will annoy their customers enough to either say 'no' anyway or not use the app in the first place. Its a black blotch for an IOS app to request permissions that it does not need, and Apple customers call them on it in the reviews.

Whereas with android, everything is quiet and silent and people run apps without really understanding what data they are giving away, EVEN if they have read the manifest... so app writers can get away with almost anything and consumer privacy on android is poorer for it.

-Matt

Comment: Re:Have you ever used Android? (Score 1) 224

by m.dillon (#48475289) Attached to: Uber's Android App Caught Reporting Data Back Without Permission

Google changed the way the permissions are described in order to combine non-invasive permissions and invasive permissions under the same label. Even a person reading the permissions off doesn't really have a clue about how much access the app actually has to their data.

In anycase, this is why I stopped using Android phones and went with iOS. Apps can't play these sorts of games on iOS.

-Matt

Comment: Re:MO as an HDD (Score 1) 202

by m.dillon (#48475245) Attached to: Consortium Roadmap Shows 100TB Hard Drives Possible By 2025

Jeeze, I remember those. Hey, how about the Bernoulli box? I had one of those too. Might not be M.O. though. Think it was just magnetic.

There is one basic problem with megneto-optical drives and why they've basically fallen off the edge of the earth... instead of having to have one high-precision/high-bw part in the drive you now have to have two. In the world of storage, that makes it too costly a technology to produce.

-Matt

Comment: Re:So that means we're still gonna be buying (Score 1) 202

by m.dillon (#48475179) Attached to: Consortium Roadmap Shows 100TB Hard Drives Possible By 2025

Every personal laptop/desktop/server box has a SSD which holds the machine base (boot, swap, root, home dirs, etc). For laptops and workstations, the SSD also holds nominal data and there is no HDD at all. On the servers, the SSD is beefier and also caches the HDD.

Bulk data is stored on a large 2TB HDD on the server and exported via NFS and samba. There's another 2TB spare on the server.

There is a backup machine on the LAN in another part of the house with a 2TB HDD and there is an off-site backup machine in a colo with two 2TB HDDs (in addition to the normal SSD as described above). Both have around 60 days worth of incremental backups of everything.

I gave up using RAID of any sort for personal data long ago. It just makes things *less* dependable and unnecessarily expensive in heat and power. Not even needed for speed since the SSD will cache ~200GB worth of HDD data.

Right now my personal data (the permanent data that I back up) clocks in at around 1TB. 90% of it is pictures and videos (DSLRs generate a godawful amount of data, the RAWs are 20-40MB each).

I don't download videos or music. No point any more when it can all be streamed. I don't know anyone who bothers storing 3rd party video any more. However, I have friends who were CD junkies before CDs died away and do maintain large music libraries. I also know a few people who run torrents and sometimes dedicate a TB or two to that, but certainly there is no reason to back up something like a torrent let alone waste a RAID on it. I don't see the point myself, it's just a huge waste of power and bandwidth.

For the DragonFlyBSD project we run a 12-blade server in the colo, each with four 2.5" drives. One or two SSDs (boot + swap + hddcache + home dirs on most of the blades), and 1-3 HDDs for temporary bulk data which we don't bother backing up. e.g. build boxes. With a few spare blades in case something fails. SSDs hold anything important, except for the developer blade but now that I look at it, the 'backed up' portion of peoples home dirs on the developer box only clocks in at 83G so that could go onto the SSD as well. The working storage that isn't backed up is currently running ~400G or so of used space, mostly crash dumps and copies of build trees and such. Everything that we care about is backed up locally and remotely but again it only amounts to a ~1TB or so. Most of the bulk data on the blades, like copies of numerous source repos, is generated and does not need to be backed up.

-Matt

Comment: Re:HDD Pros (Score 1) 433

by m.dillon (#48465007) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

HDDs are not as recoverable as you seem to think. I have several bricked drives to show for it. Plus there is a trade-off in that your HDD's chance of failure goes up dramatically over time no matter how little or how much you use it. Even keeping it on a shelf won't make it last longer. SSD failure mechanics are very different beasts. If your SSD is barely worn after 3 years of operation (and most will be), the failure rate will not be appreciably higher than when it was new. The chance of multi-bit failures eventually overcoming the automatic SCAN/relocation (in SMART) will increase once appreciable wear occurs, but the wear is write-based and not time-based and for most SSD users that means reliability will be maintainable far longer than the 3 years one can normally depend on a HDD for (assuming it isn't one of those 5% of HDDs which fails every year anyway).

And, again... You don't make backups? Depending on the recoverability of your hard drive virtually guarantees that you will lose all your data one day.

-Matt

Comment: Re:I like both (Score 1) 433

by m.dillon (#48464983) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

I hear this argument quite often and gotta ask... what, you don't have backups? When any of my storage dies I throw the drive away, stick in a new one, and restore from one of my two real-time backups (one on-site, one off-site). For that matter, I don't even trust any HDD that is over 3 years old. It gets replaced whether it reports any errors or not. And I've had plenty of HDDs fail with catastrophic errors over the years. Relying on a HDD to fail nicely is a false assumption.

Another statistic to keep in mind is that SSD failure rates are around 1.5% per year, compared to 5% failure rates for HDDs. And, I suspect, since HDD technology has essentially hit up against a mechanical brick wall w/regards to failure rates (if you still want to pay $80 for one), that SSD failure rates (which are more a function of firmware) will continue to drop while HDD failure rates remain about the same, from here on out. And that's assuming the HDD is powered on for the whole time. Power-down a HDD for a month and its failure rate goes up dramatically once you've powered it back on. HDDs can't even be reliably used for off-line backups, SSDs can. SSDs have a lot of room to get even better. HDDs just don't.

It is also a lot easier to run a SSD safely for many more years than a HDD simply by observing the wear indicator or sector relocation count ramp (actual life depends on the write load), where-as a hard drive's life is related more to power-up time regardless of load. If I only have to replace my SSDs (being conservative) once every 5-7 years vs my HDDs once every 3 years, that cuts many costs out right there. I have yet to have to replace a single SSD, but have replaced several HDDs purchased after that first SSD was bought. Just looking at the front-end cost doesn't really tell the whole story. Replacement cost, lost opportunity cost, time cost (time is money). There are many costs that matter just as much.

In terms of speed, I think you also don't understand the real problem. The problem is not comparing the 100-200 MByte/sec linear access time of a HDD to the 500-550 MByte/sec linear access time of a SSD. The problem is that once the computer has to seek that hard drive, that 100-200 Mbytes/sec drops to 20 MBytes/sec, and drops to 2 MBytes/sec in the worst-case. The SSD, on the other hand, will still maintain ~400-550 MBytes/sec even doing completely random accesses. Lots of things can cause this... de-duplication, for example. Background scans. Background applications (dropbox scans, security scans). Paging memory. Filesystem fragmentation. Game updates (fragmented data files). Whatever.

People notice the difference between SSDs and HDDs because of the above, and it matters even for casual users like, say, my parents, who mostly only mess with photos and videos. They notice it. It's a big deal. It's extremely annoying when a machine reacts slowly. The SSD is worth its weight in gold under those conditions. And machines these days (laptops and desktops certainly) do a lot more work in the background than they used to.

There are still situations where HDDs are useful. I use HDDs on my backup boxes and in situations where I need hundreds of gigabytes of temporary (but linear) storage... mostly throw-away situations where I don't care if a drive dies on me. But on my laptops and workstations it's SSD-only now, and they are a lot happier for it. For that matter, in a year or two most of our servers will likely be SSD-only as well. Only the big crunchers will need HDDs at all.

Nobody who has switched from a HDD to a SSD ever switches back. People will happily take a big storage hit ($150 2TB HDD -> $150 256GB SSD) just to be able to have that SSD. Not a whole lot of people need huge amounts of storage anyway with so much video and audio now being streamed from the cloud. For that matter, even personal storage is starting to get backed up 'on the cloud' and there is no need to have a completely local copy of *everything* (though I personally do still keep a local copy).

-Matt

Comment: Re:What about long-term data integrity? (Score 2) 433

by m.dillon (#48464795) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

You might as well ask the same question about a hard drive. If you power down a hard drive and put it on a shelf for a year, there is a better than even change that it will be dead when you try to power it up again, and an even higher chance that it will die within a few days.

A powered-down SSD that has been written once should be able to retain data for ~10 years or so. Longer if kept in a cool place. As wear builds up, the retention time drops. You can look up the flash chip specs to get a more precise answer. A powered-up SSD should be able to retain data almost indefinitely as the self check will relocate failing sectors as they lose charge. However, in practical terms, it also depends on how the drive firmware is stored. The drive will die when the firmware is no longer readable. But that is true for hard drives as well.

-Matt

Comment: Re:Question (Score 1) 433

by m.dillon (#48463859) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

Hybrid drives do not use their meager flash to cache writes. The flash would wear out in an instant if they did that. It's strictly useful only for boot data and that is pretty much it, if a few seconds matters to you and you don't want to buy a separate SSD. For any real workload, the hybrid drive is a joke.

-Matt

Comment: Re:Question (Score 1) 433

by m.dillon (#48463803) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

Never buy hybrid drives, period. You are just multplying the complexity of the firmware (resulting in more bugs, as Seagate's earlier attempts at Hybrid drives revealed), and decreasing the determinism of the failure cases. And there's no point. A hybrid drive has a *tiny* amount of flash on it. It's good for booting and perhaps holding a program or two, and that is pretty much it. For someone who does so little on their computer that it would actually fit on the flash portion of a hybrid, a hard drive will be almost as fast. For someone who uses the computer more significantly, the hybrid flash is too small to matter.

My recommendation is to use only a SSD for workstations and desktops as long as you don't need terrabytes of storage. For your server, if you can't afford a large enough SSD, then a SSD+HDD combination (or SSD + HDD/RAID) works very well. In this situation you put the boot and swap space and the SSD, plus you cache HDD data on your SSD.

This is pretty much what we do on our systems now. The workstations and desktops are SSD-only, the servers are SSD + HDD(s).

The nice thing about this is that with, say, a 256G SSD on the server caching roughly ~200GB worth of HDD data, the HDD's do not require a lot of performance. We can just use 2.5" 2TB green drives. Plus we can use large swap-backed ram disks and so on and so forth. Makes the servers scream.

-Matt

Comment: Re:LOL (Score 1) 433

by m.dillon (#48463145) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

A 7200 rpm HDD can do 200-400 IOPS or so, semi-random accesses (normal database access patterns). A 15K HDD can do ~400-600 or so. Short-stroking a normal drive also gains you at least 100 IOPS (so, say 300-500 IOPS on a short-stroked 7200 rpm HDD). That's off the top of my head.

A SATA SSD, of course, can do 60000-100000 IOPS or so and a PCI-e SSD can do even more.

-Matt

Comment: Re:Reliability (Score 2) 433

by m.dillon (#48463105) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

Depends on the application. For a workstation or build box, we configure swap on the SSD.

The point is not that the build box needs to swap, not with 32G or more ram, but that having swap in the mix allows you to make full use of your cpu resources because you can scale the build up to the point where the 'peaks' of the build tend to eat just a tad more ram resources than you have ram for (and thus page), which is fine because the rest of the build winds up being able to better-utilize the ram and cpu that is there. So putting swap on a SSD actually works out quite nicely on a build box.

Similarly, for a workstation, the machine simply does not page enough that one has to worry about paging wearing out the SSD. You put swap on your SSD for another reason entirely... to allow the machine to hold onto huge amounts of data in virtual memory from open applications, and to allow the machine to get rid of idle memory (page it out) to make more memory available for active operations, without you as the user of the workstation noticing when it actually pages something in or out.

A good example of this is when doing mass photo-editing on hundreds of gigabytes of data. If the bulk storage is not a SSD, or perhaps if it is accessed over a network that can cause problems. But if the program caches pictures ahead and behind and 'sees' a large amount of memory is available, having swap on the SSD can improve performance and latency massively.

And, of course, being able to cache HDD or networked data on your SSD is just as important, so it depends how the cache mechanism works in the OS.

So generally speaking, there are actually not very many situations where you WOULDN'T want to put your swap on the SSD. On machines with large ram configurations, the name of the game is to make the most of the resources you have and not so much to overload the machine to the point where it is paging heavily 24x7. On machines with less ram, the name of the game is to reduce latency for the workload, which means allowing the OS to page so available ram can self-tune to the workload.

-Matt

Comment: Inevitable (Score 1) 433

by m.dillon (#48462755) Attached to: How Intel and Micron May Finally Kill the Hard Disk Drive

Happening a little sooner than I thought, but the trend has clearly been going in this direction for a long time now. Just one year ago I stopped buying 3.5" HDDs a year ago in favor of a combination of (short stroked) 2.5" drives and SSDs. I already use only SSDs in all the workstations and laptops, the HDDs are only used by the servers now.

Now it is looking like I will probably not buy any more HDDs at all, ever again, even for the servers. That is going to do wonders for hardware life and maintenance costs.

It's a bit strange having a pile of brand-new perfectly working 1TB and 2TB 3.5" HDDs still in their static bags, unopened, in my spare drawer that I will likely never use again.

I wonder how long it will take case makers to start giving us 2.5"-only hot swap options without all the 3.5" crap taking up room. Of course, there are some already... I mean for it to become the predominant case style.

-Matt

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