baruch

18 ms·

121.
by baruch 11y ago
When the data is consistent for several years you should already figure out that Seagate is not going to improve so fast, when they do improve in BackBlaze data you can start buying them again. Large companies may buy Seagate due to the pri
122.
by baruch 11y ago
I used LyX mostly in my university year after Word crashed and took down a glorious formula document I needed for a test. LyX was better for editing math and the documents looked gorgeous without me needing to know what made them so nice. I
123.
by baruch 11y ago
I like the look of a LaTeX document better than that of a Word document by a mile. You can probably get a Word document to look great as well but in LaTeX it happens by default. It actually provides you proper typographical advantages witho
124.
by baruch 11y ago
It doesn't require a VM pause to cause a system freeze, an SMI interrupt can do that as well. It doesn't take a lot to have backwards time travel, NTP can do that for you as well in some bad configurations. It's very hard to
125.
by baruch 11y ago
> NTP only drifts the clock (under normal operation). That shouldn't be an assumption. NTP may jump the clock if the difference is too high, I've had it once that a system was connected to two different NTP servers and they eac
126.
by baruch 11y ago
In RAID6 you can find which of the different combinations shows a mismatch and which combination doesn't. Run through all combinations and find the one that shows no mismatch, the dropped drive is the one with the bad data, rewrite it
127.
by baruch 11y ago
One can see tens of ms from an SSD if you run it long enough and hard enough. It is also possible to get hundreds of ms and even seconds if the SSD is getting bad. It's true that 99% of your IOs will see service time of below 1ms but i
128.
by baruch 11y ago
I can tell you that EMC and IBM both use the same drives from the same batch in an entire system of tens to hundreds of drives and while I don't know about all cases completely I did oversee a large number of systems and drives and the
129.
by baruch 11y ago
Where does one find 10us reads? The NAND is usually with a Tread of 50 to 100 us so just the NAND operation itself is more than 10us. Tprog is around 1ms and Terase can be upwards of 2ms. All in all this means a large variability in read pe
130.
by baruch 11y ago
I just created a quick hack which is essentially at this level but I would try to improve upon it, it can be found at: https://github.com/baruch/sortedtar
131.
by baruch 11y ago
Check if the original was compressed with a higher level than you just did. Decompress the file and recompress and you should get the same file size.
132.
by baruch 11y ago
Different people will want different sorts for different needs, you can already feed tar the list of sorted files so it only takes another program to provide the specific sorted order for you. I actually do not really know why they bothered
133.
by baruch 11y ago
I usually use something like the following to do it: find $DIR -type f | rev | sort | rev | tar -cv -T /dev/stdin -f $OUTPUT.tar Add a -j or -z or any other compressor you want. This will sort the files on reverse filename order s
134.
by baruch 11y ago
Most non-enterprise SSDs do not have an internal supercap or other power protection mechanism and they are not intended for a server use-case and shouldn't be used in such capacity. An HDD will not hold data that is written to its writ
135.
by baruch 11y ago
So now we need to create a web service to send multiple requests and auto-cancel when the first one is accepted. The chance of auto-accepting within the minutes needed to respond should be small, unless you sent to the same host multiple re
136.
by baruch 11y ago
An addition to that is that getting things right sometimes takes multiple attempts, at least for me. I've seen that in that work I attempted to do for the Linux Kernel TCP stack and also in prior and later work related projects. Large
137.
by baruch 11y ago
There are few small patches of mine that did enter: 8a3c3a9 [TCP]: Check num sacks in SACK fast path 6f74651 [TCP]: Seperate DSACK from SACK fast path fda03fb [TCP]: Advance fast path pointer for first block only db3ccda [
138.
by baruch 11y ago
These are complex parts of the kernel and since they impact virtually any user getting anything wrong is bad. It takes a while to merge such changes and to even just get them right in order to feel fine with submitting such changes. I'
139.
by baruch 11y ago
As with any new code, it may have bugs. The kernel could deadlock or crash due to insufficient locking. You may want to start small and report any bugs that you find to help improve the code.
140.
by baruch 11y ago
It's the basis for another project of his called 'fleet': https://github.com/marssaxman/fleet The idea for fleet (and thus for startc) is to work inside a hypervisor (kvm) instead of real hardware so you
141.
by baruch 11y ago
The article says Dell intends to pay $25 per share when the current trading price is $27. That's not a premium, that's a discount. Edit: Looks like I misunderstood the terms. It's $25 plus a tracking stock for VMWare that is
142.
by baruch 11y ago
Large embedded systems also like malloc-less solutions. In such systems you essentially have explicit use for all the memory you have and you don't like to buy extra memory that is unused (reduces your margins). When you need to accoun
143.
by baruch 11y ago
I use websec for a few such blogs, it emails me the content and even highlights the changed parts in the page. It's a program I inherited after it was abandoned and did some maintenance on so I'm biased, I haven't updated it
144.
by baruch 11y ago
That's still not easy enough to do. UDP is simple enough but doing TCP in those drivers is still a pain. There are DPDK with LWIP or with some BSD tacked on top but so far I didn't find something that I can just take for a ride in
145.
by baruch 11y ago
I don't think that testing by Facebook is going to help you unless you are using the exact same model as they are and are assured of using their exact firmware. At work we use SAS SSDs in large quantities and the firmware we use is cus
146.
by baruch 11y ago
Unless someone used continue inside that loop by mistake...
147.
Predicting disk failures to prevent RAID multi-disk failure(usenix.org)
1 points by baruch 11y ago|0 comments
148.
by baruch 11y ago
The vendors are always very mindful of every cent they put in extra in the product that doesn't give a meaningful effect on the bottom line (i.e. increase sales or prevents sales from falling off). As long as customers are buying the p
149.
by baruch 11y ago
Not quite. An SSD at 85% wearout will take longer to program and erase the blocks and it will require more refreshes (data retention suffers) so there will be considerably more background operations. In fact SSD vendors do quite a bit to ma
150.
by baruch 11y ago
It can work out nicely if most of what you do is the size of the SSD and the total capacity is higher than the SSD capacity (i.e. lots of rarely used stuff). In fact, I worked on an enterprise storage that did just that and it significantly

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