mgerdts

22 ms·

241.
by mgerdts 4y ago
The last time I needed to use fsck to repair a filesystem was less than six months ago. After running it I found that my entire directory hierarchy was garbage and lost+found had at least hundreds of files named by their inode numbers. It
242.
by mgerdts 4y ago
> Is it known how much plaintext could potentially leak to disk outside encrypted ZFS datasets, possibly accessible by forensic analysis? When a write to an encrypted dataset happens, no plaintext data is written to disk. Your data is e
243.
by mgerdts 4y ago
Everything outside of encrypted datasets’ data is not encrypted. This includes the things you mention as well as vdev labels, block pointers, etc. The clear text bits can tell you a fair amount about the relative age of written data and h
244.
by mgerdts 4y ago
Zfs has a per dataset data encryption key. When you destroy a filesystem or volume, the key is also destroyed. This makes recovery of data in deleted datasets exceedingly hard even with raw disk access. LUKS and other FDE schemes tend not t
245.
by mgerdts 4y ago
> The fact that not all metadata is encrypted This was one of my concerns when I first encountered this trade off in Solaris zfs. That is, you claim that the Solaris zfs encryption is better in this regard but it’s not.
246.
by mgerdts 4y ago
Many of the open source zfs developers are the same ones that developed zfs at Sun and then Oracle. I worked on the Solaris team from 2010 until 2017 and have contributed to open source zfs implantations in illumos and openzfs. Your critici
247.
by mgerdts 4y ago
10 Gb/s =~ 1.2 GB/s Each 980 Pro can do sequential reads at 7 GB/s. ZFS with record size 128 KiB will do IOs at a size that will perform about as well as sequential regardless of the actual pattern. AFAICT ZFS has no need to
248.
It’s my fault that AD replication can use SMTP(twitter.com)
1 points by mgerdts 4y ago|0 comments
249.
by mgerdts 4y ago
SATA SSDs top out at about 550 MB/s. ZFS does ok with these. NMVe SSDs top out at somewhere between 3000 MB/s (typical enterprise PCIe Gen 3) and 14000 MB/s (mythical just released PCIe Gen 5 drives). ZFS (out of the box, any
250.
by mgerdts 4y ago
I've added [1] to my reading list. Do you have suggestions for others that relate specifically to WAF? 1. http://supertech.csail.mit.edu/papers/BenderFaJa15.pdf
251.
by mgerdts 4y ago
That makes sense. The numbers from standards and spec sheets do look quite pessimistic compared to the retention I’ve experienced with cheap USB drives and old SD cards that are rarely powered.
252.
by mgerdts 4y ago
This doesn’t account for the write amplification factor, which is quite unlikely to be 1 with a naive wear leveling implementation and the most brutal write workload.
253.
by mgerdts 4y ago
And NAND has an electrical charge that will dissipate, eventually leading to data loss. This time period is on the order of 90 days (I think I’ve seen some data sheets saying 30 days) up to one year. https://www.jedec.org/si
254.
by mgerdts 4y ago
If I will need to access individual files or it needs to be usable by others on arbitrary operating systems, zip is best. Random access is greatly helped by the directory at the end of a zip file. .tar.*z is particularly hostile to random
255.
by mgerdts 4y ago
This is not a problem with the file format, it is a problem with the program that is interpreting it.
256.
by mgerdts 4y ago
Except for carbon monoxide, soot, etc., that contribute to a variety of health problems.
257.
by mgerdts 4y ago
> It makes a lot more sense to transport the energy to the water than vice versa. That’s my gut feeling as well. Perhaps the location of the consumer of the hydrocarbons would change that in some cases.
258.
by mgerdts 4y ago
Making hydrocarbons for airplanes and maybe for cargo ships makes sense unless the power density of batteries increases dramatically. Creating hydrocarbons to put into commuter cars and trucks that traverse developed regions sounds like a b
259.
by mgerdts 4y ago
There's a lot of optimism in this article. Perhaps too much as it seems to gloss over some important details. > Our process works by using solar power to split water into hydrogen and oxygen, concentrating CO2 from the atmosphere, t
260.
by mgerdts 4y ago
> Imagine someday giant vessels growing tomato plants in the dark and on Mars—how much easier would that be for future Martians? Tomatoes are naturally pollinated only by bees. If you don’t have pollination, you don’t have tomatoes. Arti
261.
by mgerdts 4y ago
Did you live in an area sparsely populated by families with children that matched your child’s age, or did you choose (or forced to use for desegregation) a school that was far away? The fact that transit was an option makes me think it wa
262.
by mgerdts 4y ago
> The point is there's no need to move blocks, just stop writing to worn-out blocks, and then the CoW nature of the filesystem will take care of the rest. Suppose the file system stores photos and videos that the owner tends to keep
263.
by mgerdts 4y ago
> The nearly 3× increase in firesystem capacity the authors report might be worth a significant amount of software work? They aren't claiming 2.94x capacity increase, they are claiming 2.94x endurance. Per the paper's claims,
264.
by mgerdts 4y ago
> ZFS is the best placed to deal with that break and do its own, intelligent wear leveling Part of wear leveling is to rewrite old static data to blocks that are more worn so that the relatively fresh blocks that have been long squatted
265.
by mgerdts 4y ago
This morning there was an ad during Face the Nation for portal. It was very focused on business uses. Gone are the days of grandpa reading a book to his grandchild adorned with VR animal ears. Having been on family zoom calls with some part
266.
by mgerdts 4y ago
I recently helped someone set up a dell optiplex 7090 small form factor PC. Much to my surprise it came with a proper serial port. https://www.dell.com/en-us/work/shop/desktops-all-in-one-pcs...
267.
by mgerdts 4y ago
If the trusted web service is under law enforcement order to decrypt mail of a particular user, a version of the JavaScript code that breaks the encryption could be delivered to only that user. No third party experts will be aware of this s
268.
by mgerdts 4y ago
I think the key criticism here is that since they deliver the code (javascript) that handles the keys, they could easily replace the code with a version that leaks/harvests your private key. Once your private key is known by someone th
269.
by mgerdts 4y ago
I've found that the write pattern can have an effect on future reads. For instance, I've seen random 4k writes followed by 1m reads result in a somewhat lower read rate than if the writes were originally done as 1m writes. The de
270.
by mgerdts 4y ago
> You have to take a contiguous block of 2M, wipe the entire thing, rewrite whatever part of it was useful, This is called garbage collection. It may be happening at any time in the background but becomes more frequent and perhaps in th

More ›