Subject: Storage | August 9, 2016 - 09:59 PM | Allyn Malventano
Tagged: XPoint, Worm, storage, ssd, RocksDB, Optane, nand, flash, facebook
At their FMS 2016 Keynote, Facebook gave us some details on the various storage technologies that fuel their massive operation:
In the four corners above, they covered the full spectrum of storing bits. From NVMe to Lightning (huge racks of flash (JBOF)), to AVA (quad M.2 22110 NVMe SSDs), to the new kid on the block, WORM storage. WORM stands for Write Once Read Many, and as you might imagine, Facebook has lots of archival data that they would like to be able to read quickly, so this sort of storage fits the bill nicely. How do you pull off massive capacity in flash devices? QLC. Forget MLC or TLC, QLC stores four bits per cell, meaning there are 16 individual voltage states for each cell. This requires extremely precise writing techniques and reads must appropriately compensate for cell drift over time, and while this was a near impossibility with planar NAND, 3D NAND has more volume to store those electrons. This means one can trade the endurance gains of 3D NAND for higher bit density, ultimately enabling SSDs upwards of ~100TB in capacity. The catch is that they are rated at only ~150 write cycles. This is fine for archival storage requiring WORM workloads, and you still maintain NAND speeds when it comes to reading that data later on, meaning that decade old Facebook post will appear in your browser just as quickly as the one you posted ten minutes ago.
Next up was a look at some preliminary Intel Optane SSD results using RocksDB. Compared to a P3600, the prototype Optane part offers impressive gains in Facebook's real-world workload. Throughput jumped by 3x, and latency reduced to 1/10th of its previous value. These are impressive gains given this fairly heavy mixed workload.
More to follow from FMS 2016!
Subject: General Tech | January 26, 2012 - 05:47 PM | Jeremy Hellstrom
Tagged: fud, Malware, Virus, Worm
Back in the ancient days of gaming and repeated in Skyrim's Draugr your enemies started out simple, a simple zombie or leever becoming a Infected Death Lord Zombie of Fiery Devastation. Another way to look at is a supervillain origin story where exposure to something that should have killed them instead grants them powers beyond mere mortals. There may have also been a dozen decent SciFi novels written about the topic (well, probably more like a gross) ... however you look at it, computer worms are mutating!
It seems that systems infected with a worm are being hit by certain viruses which inadvertently infect the worm, creating malware with twice the command and control servers, twice the backdoors and twice the methods to spread its self. The Register cites a specific example of the Rimecud worm which steals passwords becoming infected by Virtob which creates a backdoor on a system. At this moment BitDefender has found that 0.4% of the infected systems they detected had an infected worm present, a number you can expect to grow.
Be careful out there!
"Viruses are accidentally infecting worms on victims’ computers, creating super-powered strains of hybrid software nasties.
The monster malware spreads quicker than before, screws up systems worse than ever, and exposes private data in a way not even envisioned by the original virus writers.
A study by antivirus outfit BitDefender found 40,000 such "Frankenmalware samples" in a study of 10 million infected files in early January, or 0.4 per cent of malware strains sampled. These cybercrime chimeras pose a greater risk to infected users than standard malware, the Romanian antivirus firm warns."
Here is some more Tech News from around the web:
- Real-time depth smoothing for the Kinect @ Hack a Day
- TurboTax Premier Online (2011) Review @ TechReviewSource
- pcAnywhere let anyone anywhere inject code into PCs @ The Register
- Jam a remote helicopter @ Hack a Day
- Nvidia hit by GPU slump, too @ The Register