12 ms·
Modern HDDs have gotten somewhat better
- Lramseyer 4y agoFun fact: The dimensions of a magnet (a bit of data) on an HDD are actually rectangular. It's about 3-5x wider than it is long. This favors read/write speed, since you cover more bits per rotational length. Aside from the obvious speed boost you get from it, it's also done to make it easier to stay on track. One of the huge limitations with bit width is the ability to keep the actuator arm stable within the 15 or so nanometers because of the air turbulence. That's why they fill the drives with helium now, less aerodynamic drag/turbulence means you can either cram more platters in (which increases the turbulence back to where it originally was) or make narrower tracks since you have more precision.
- EarthLaunch 4y agoIs it too hard to maintain vacuum? The comparison I can think of is a thermos, which I'm told uses a vacuum layer between the eg coffee, and the outside.
- invalidator 4y agoVacuum won't work with current technology. The heads use air currents to fly a few nanometers over the platter. If you put a running drive in a vacuum chamber the heads will touch down and everything will be destroyed. https://en.wikipedia.org/wiki/Flying_height https://en.wikipedia.org/wiki/Flying_height
- deleted 4y ago[deleted]
- KennyBlanken 4y agoIs the status quo on drive firmware lying about what's actually been flushed to media still as terrible as it was, oh, twenty years ago? A friend used to work for Apple and said that one of the reasons they had apple-specific versions of various mass market SCSI and IDE drives was because Apple's firmware actually flushed data to disk when told to do so, and didn't lie about whether data was flushed or not.
- dktoao 4y agoIf there is un-written cached data there is a capacitor bank that allows this data to be quickly written to non-volatile flash and rw heads to be retracted in the event of power loss. They test this feature pretty heavily, esp. in enterprise drives. Source: used to work for an HDD manufacturer. So, they might be lying to you but it is pretty useless information on for modern drives.
- colejohnson66 4y agoBasically, "flushed" means safe. Whether it's written to internal DRAM/SRAM (with power-loss prevention), NV flash, or the actual platter is irrelevant. When in history did the lie start to not matter?
- dvanders 4y agoThe other interesting thing about modern data centre HDDs is they have a media cache which significantly accelerates synchronous random write IOPS - OOTB these drives get 75 IOPS with fio fsync=1 bs=4k randwrite, but with a WCE=0 they can do 400 IOPS. So if your app is fsync heavy (such as Ceph) then you can switch on this media cache by setting the drive to write through mode (WCE=0). SATA SSDs have a similar quirk.
- gandalfff 4y agoHow are the random reads/writes? AFAIK this contributes a lot to a device feeling responsive.
- dragontamer 4y agoThis is the result of "more bits-per-inch", which is the natural result of going from 4TB-per-drive to 20TB-per-drive. Yes, I'm skipping a few steps, but that's the fundamental issue at play here. There's more platters, more bits per inch, more read / write speed at the same 7200 RPM. Its not a lot, but its a steady increase as hard drives keep getting denser and denser.
- zeckalpha 4y agoUsing a single Prometheus node with redundant drives rather than redundant nodes with single drives is an odd choice to me. Why replicate at block level when layer 7 has support?
- siebenmann 4y agoA multi-node Prometheus setup is significantly more complex to design and operate than a Linux software RAID mirror, especially once you throw in Grafana, Alertmanager, and so on. Distributed anything makes it harder. The layer 7 may 'support' this, but it's not a plug and play setup. (It also requires more hardware.) (I'm the author of the linked-to entry.)
- peanut_worm 4y agoI stopped using HDDs all together like 8 years ago and I haven’t had any issues at all
- ghostly_s 4y agoArticles that could have been a tweet
- JoeyBananas 4y agoI'm never buying another HDD in my life. There are a few tasks that take weeks on an HDD but only hours on an SSD. And the price difference is often negligible.
- binkHN 4y agoTL;DR: Modern 7200RPM 20TB HDDs can do 230MB/sec sustained—which was news to me!
- Helitico 4y agoOnly takes you 8 days to read it, funny right? ;)
- chrismorgan 4y ago230MB/s, not 230Mbps; one day, not eight.
- matja 4y agoThere's one that can do over 500MB/s : https://www.storagereview.com/news/seagate-exos-2x14-hdd-delivers-524mb-s https://www.storagereview.com/news/seagate-exos-2x14-hdd-del...
- oblak 4y agoYou've been out of the loop for a while. Certain HDDs have been able to achieve such speeds for about a decade, if not more. Most of their (slow) gains over the last 10 years have been in capacity.
- sithadmin 4y agoYes, but that appears to be if you're doing sequential reads. Works for a handful of use cases, but not most normal desktop or server workloads.
- dylan604 4y agoSounds ideal for large arrays for video post use. We used to string 16 drives together to get speeds of what a modern m.2 SSD can do as a single drive. Only, the arrays gave you the capacity to do useful things rather than the toy-like capacity of 2-4TB SSDs. Doubling the speed of spining rust might be interesting when building RAID-6 volumes for edit bays
- 4y ago
- antongribok 4y agoI actually ran into this last year. We ordered about 2 thousand 8TB HDDs last year for a Ceph cluster and had an agreement with our server vendor that they are not supposed to substitute the HDD model. Well, seems like they ran out and a small fraction of the drives were of a different, older model. The performance difference was 2.5x for our workload: Older model: 670 IO/s and 2.9 ms average latency Newer model: 1680 IO/s and 1.1 ms average latency We got the vendor to send us new drives and shipped the older model back to them.
- sithadmin 4y agoWas the 'older model' in this case one of the models where it is known that manufacturers were shipping SMR drives without disclosing it?
- antongribok 4y agoNo. Both models were PMR. I tried to find out more about what the differences are from the manufacturer, but didn't get far. Perhaps someone here can shed some light. Older drive: model number: MB8000GFECR SATA Version: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s) ATA Version: ACS-3 T13/2161-D revision 5 Newer drive: model number: MB008000GWWQU SATA Version: SATA 3.3, 6.0 Gb/s (current: 6.0 Gb/s) ATA Version: ACS-4 My guess at the time was that the newer drive had a deeper command queue, but I'm not actually sure, and I think both drives had the same amount of cache.
- deleted 4y ago[deleted]
- sithadmin 4y agoI'm not seeing any especially obvious differences between those models (aside from the ones you listed). Were the drive versions mixed in alongside each other behind the same storage controller? If so, I would wonder if perhaps the controller's handling of different SATA versions played a role.
- seventytwo 4y agoAt 7200rpm, would increased data density on the disk account for this? These new ones are HAMR…
- wmf 4y agoYes, exactly. The drive has to be faster to keep up with the platters.
- causi 4y ago230MB, 100MB, or 50MB per second doesn't make that big a difference for anything I'd use a HDD for. What I want is lower pricing. The 12TB drive I bought two years ago hasn't changed in price. The 8TB drive I bought four years ago is $30 more expensive now than it was then.
- usrn 4y agoI think we might be hitting a point where technology improvements can no longer outrun inflation.
- mlyle 4y agoAll kinds of "legacy" products go up in price-- RAM a couple generations back, etc. SSDs have won. Spinning hard drives are going to ship fewer and fewer units. The economies of scale are not going to improve ever again and are already getting worse. Further, the market just doesn't care about paying for capacity for the most part. We peaked in 2010 with 650 million drives/year. Current unit counts are about one third of that. Compare to SSDs with about 400 million units/year.
- amelius 4y agoAll I want is a cheap tape drive for backups. Seek can be slow, as long as throughput is high.
- kloch 4y ago> because of course disk vendors quote everything in the smaller SI units). SI prefixes should be (and are) the rule rather than the exception. It only made sense to measure ram in base-2 units because they are manufactured according to base-2 addressing. HDD’s have never used base 2 addressing. Another example is network media. Serialized data transfer speed is measured in {K,M,G,T}b/s (bits) or B/s (Bytes) where a Gigabit is exactly 1000000000 bits and Gigabyte is exactly 1000000000 bytes. In the early days of computers ram was extremely scarce and expensive. It was such a limitation that it was usually the very first question you asked about a computer’s capabilities. I remember in 5th grade asking a fellow student who’s parents had just bought an Atari 800 “How much ‘K’ does it have?” This intense focus on ram may have led people to assume that it’s odd nomenclature would apply to anything computer related.
- yread 4y agoWell but they did use 512 B sectors
- jeroenhd 4y agoBase 2 is used in the world's most common desktop operating system(s) so it's no surprise that people get confused. They buy a hard drive that's supposed to be 1TB and when they install it their computer says it's 0.9TB, that's surprising to those not in the know. Despite hard drive manufacturers using correct units, people still blame hard drive manufacturers for their disappointment.
- 4y ago