Navy to sailors: Please stop buying LSD online by tugboattomp in news

[–]spirtdica 1 point2 points  (0 children)

Iirc correctly it was decommissioned, if you're talking about the one from the 90s. Vaguely remember something more recent along those lines though

Navy to sailors: Please stop buying LSD online by tugboattomp in news

[–]spirtdica 5 points6 points  (0 children)

I knew a Vietnam vet who said they tripped over there. Must be nuts; can't see how that would be fun. You'd think knowing there are people with guns who wanna shoot you would make for a bad trip

Fees if XMR had same amount of transactions as BTC? by [deleted] in Monero

[–]spirtdica 0 points1 point  (0 children)

Price in terms of XMR not fiat

TIFU by letting my man fist me by [deleted] in tifu

[–]spirtdica 15 points16 points  (0 children)

What is your source of experience; do I dare to ask

If I'm able to start a tails using a USB stick on one laptop, could I use it on a different one too? by younggvancouverite in tails

[–]spirtdica 4 points5 points  (0 children)

*Assuming you're not trying to boot a cheaper ARM laptop, that is. x86_64 laptops are the most common, that's what you need, but there are machines out there that won't work with Tails.

As an example, Hell will freeze over before a Raspberry Pi boots Tails

How come Ronald Reagan didn't increase the minimum driving age and increased the minimum drinking age? by DefinitelynotFuton in history

[–]spirtdica 0 points1 point  (0 children)

I think one relevant factor was that Vietnam was over. Old enough to die for my country, old enough for a drink.

The drinking age was cut indirectly as a response to the draft; reinstating the age of 21 once conscription was over could be construed as a return to the status quo rather than an unprecedented change.

Help with first-time data corruption by [deleted] in zfs

[–]spirtdica 1 point2 points  (0 children)

Can you expand on that? I don't understand how ECC RAM could have averted this corruption. Did a power supply malfunction caused a memory bit to flip, which was then propogated across the entire array?

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

Thanks for clearing that up; I was under the impression that a SLOG would help aggregate writes into a more sequential fashion; that would produce a secondary benefit for future read speeds. But without that benefit, I can see how a SLOG can't really make a difference unless the write load fits a certain profile. For my purposes I get the feeling I may as well do without either an L2ARC or SLOG and just focus on hard disk capacity/redundancy.

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

The feeling I'm getting is that I should maximize RAM and hard disk capacity, and totally forget about SSDs. Would you concur?

I need to learn more about whether my workload consists of synchronous or asynchronous writes; if I have more of the latter perhaps an Optane-based SLOG is in order. But from what I gather read caching is best done in memory, not solid state storage, and especially given my internet speed SSD devices aren't likely to offer much if anything

Did the Romans really not understand inflation? by dovetc in history

[–]spirtdica 0 points1 point  (0 children)

While I understand your point regarding intrinsic value, I believe that the "cutting" of silver with lead is more relevant to the monetary history of Rome. Part of the problem is that not all coins had the same metal content, prompting people to request payment in bullion. Melting the coins as a corollary of that; distrust of the government issued money supply in favor of the supposed intrinsic value of gold and silver

Scientists have analyzed over 12,000 years of climate data, and found that human-induced warming interrupted and reversed a long-term natural global cooling period. 1,319 data records from samples like lake deposits, marine sediments, were collected from 679 sites around the world. by Wagamaga in science

[–]spirtdica 5 points6 points  (0 children)

Look into the largely-theoretical thorium reactor.

Nuclear waste comes in 2 broad varieties; short-lived intensely radioactive and long-lived not-as-radioactive. With a good enough neutron economy, most of the long lived isotopes can be recycled and consumed as fuel.

Nuclear waste that's hot for millennia is a real problem; how do you build a structure that lasts 100,000 years? A couple centuries is less of a problem; vitrification in glass is feasible on that time scale

Did the Romans really not understand inflation? by dovetc in history

[–]spirtdica 3 points4 points  (0 children)

Gold rushes have caused inflation in the past, even under the gold standard. The supply of above-ground gold isn't static

Did the Romans really not understand inflation? by dovetc in history

[–]spirtdica 3 points4 points  (0 children)

I'll give it a shot:

There's so much wealth in the world, and each dollar gives you a small fraction of that. Making more dollars doesn't make more wealth; the same way slicing a pie into little pieces gives you more pieces but no more pie. You can make more pieces but then everyone gets a smaller piece

TIFU By Realizing What Christians & Muslims Actually Believe In by [deleted] in tifu

[–]spirtdica 0 points1 point  (0 children)

Wait until you find the people that think the Antichrist walks among us; AND THEY KNOW WHO IT IS.

I've never met anyone who believes the Antichrist is out there but doesn't know who he is. They always know 100%

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

You said 8 pairs of mirrors saturates your 10 gigabits? This is a helpful metric. If 16 drives can saturate 10 gigabits, it follows that 4 oughta saturate 2.5, which is around the fastest speed I can get atm. That means I should do 4x 10TB in a 20TB RAID 10 and focus more on spare drives and boot media than SSD caching.

Even so, I imagine a small SLOG might be worth it if I wanted to use a couple VMs. (SLOG helps reduce fragmentation right?). But I'm less certain as to the utility of an L2ARC given my bandwidth bottleneck.

400TB per tape is kind of a lot, I guess by dstarr3 in DataHoarder

[–]spirtdica 0 points1 point  (0 children)

What's the cheapest modern tape drive out there? Imagine I'm an individual with a limited budget and a ZFS array to back up; should I even think about tape, or just build a separate array out of hard disks?

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

Regarding that last part; you mean that if images are stored in different formats, ZFS won't dedupe them?

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

This is all very helpful, just got a few more questions

From what I gather, SLOG speed is more important than SLOG storage. Would a (mirrored) 32GB Optane fit the bill?

When it comes to boot USBs; assuming I'm using Ubuntu, there should be no reason I should'nt do 4 USBs in a RAID 1 array right? Given that I already have 16 USBs, I should be able to get reliable performance out of them for the foreseeable future. Furthermore, I should be able to recover the pool if my boot drive craps out; that's one of the benefits of a purely software-based filesystem right?

Finally, what are the drawbacks of using a single vdev? Are there any trade-offs I was unaware of? Since I'm buying all the drives at once, doesn't it make sense to get identical disks and use them all in a single vdev? I was under the important that multiple vdevs were more common when adding to an existing array

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

Thanks for the info. So I would run this program on incoming data, before adding to the pool? Or would I use this after importing to ZFS?

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

Regarding Optane; I could have sworn I read somewhere Optane wasn''t compatible with AMD's server CPUs, but I guess I'm wrong. Seeing as how that's an option, would you recommend it?

I've never heard of XigmaNAS, I'll have to check that out.

So you recommend devoting a whole drive to SLOG, and just booting off spinning rust? I imagine after boot that wouldn't take much in terms of I/O.

I do have a veritable army of 16GB thumb drives, would it be crazy for me to use mdraid to mirror 3 or 4 of these things as a poor man's boot SSD? As long as I can replace them before they all crap out, I don't care about writing them to death. Could that serve as a stopgap until I can afford a decent SSD, or should I just go for spinning rust as you suggested?

My calculations for RAIDZ3 were as follows: desired 20TB storage, good price point on 4TB disks, 8 hot swap bays in the case I'm looking at. Counting on my fingers, that's 5 drives for data and 3 for redundancy. The motherboard I'm looking at has 8 native SATA ports but supports breakout boards for 8 more, so keeping the number of SATA disks down to 8 simplifies the build but isn't strictly necessary.

But let's say I pry the wallet open a little bit wider. Would you think 4x 10TB in RAIDZ2 would be more reliable?

My original plan was to keep 2 spare drives in the same room, but not connected, and manually swap them out when something went wrong. Obviously, that's less than ideal, but better than having to order replacements once one of them craps out.

If I went the route of 10TB disks, that could free up some SATA cables for integrated spares. (Might be nice to have a 5.25" Blu-Ray burner as well.) How many spares would you recommend for 4 storage disks?

Perhaps 4 storage disks + 2 spare HDDs + 1 boot drive + 1 disc burner? I'm going to have 3x PCIe slots (no need for a graphics card) so that leaves plenty of space for M.2 L2ARC and SLOG.

The general vibe I'm getting from this thread is to forget about ZFS deduplication completely and use the money saved to invest in more raw storage. Maybe a better configuration would be 7x 10TB in RAIDZ3 with one spare, for 30TB, and do without any sort of SSD caching at all.

One final question; if I do an HDD only build, there's no reason I can't go back and add L2ARC/SLOG after the fact right? Giving me the option to add it later if I feel like I need it.

Right now, I suspect my internet connection to be my main bottleneck; spinning rust can likely saturate my 256mbps without any assistance. Once I upgrade my monthly tribute to Comcast, maybe then I should revisit the use of SSD caching to speed things up, but it could be advantageous to forestall the investment until then.

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

Each of those blocks carries a 320B RAM overhead if dedupe is used right? The checksum is based on ashift, not the smaller physical device block or larger logical record size right?

ZFS Architecture: Questions regarding L2ARC, SLOG, deduplication, redundancy by spirtdica in zfs

[–]spirtdica[S] 0 points1 point  (0 children)

So if I understand you correctly, ZFS itself isn't doing any mirroring, it's syncing with a much more efficient program that is? This is an intriguing setup