Linux-based rebuild probably didn't use dirty page/sector logging, so 6 hours would still have been completely normal (if not even on the fast side)

Anything that claims to rebuild in an hour is only partly rebuilding.

Or if you have a very large number of very small drives. Or perhaps SSDs.

@Bob I actually don't know what this conversation is about, but hacking together linux 'md' raid sets to recover from physical/hardware RAID arrays is quite commonly used in data recovery.

@Bob Well yeah, SSDs possibly. But I was referring to >1TB hard drives (yeah I forgot the "hard", oops)

@qasdfdsaq We weren't told the actual drive layout :P

@Bob (Un)educated guess.

@qasdfdsaq Something hacked together as a last-ditch recovery attempt, I can see (let's pretend the backups disappeared in a freak accident). But, that's not really compatible in the conventional 'use them interchangeably' sense.

Linux software RAID on a modern CPU basically operates at RAM speed on mirror/stripe sets and several gigabytes per second on more complex/parity based arrays.

@Bob It's frequently used as a first/second ditch attempt. Last ditch IMO would be using custom software whose only job is to reconstruct raw RAID arrays with no metadata.

(And yes, I've done all of the above. Some software is so specialised it uses entropy patterns to figure out your array geometry)

You're not going to want to create a RAID volume in one format and then permanently mount it with other software. The correct response there is to properly rebuild the array in the new format.

@qasdfdsaq Hm... I'd call backups the first? :P

@qasdfdsaq Lemme guess. Someone missed the "RAID is not a backup" memo.

How well did that end up working?

@Bob While it's not ideal, in reality the difference between different RAID "formats" is really just one or two sectors of metadata either at the beginning or end of the drive. Everything else is exactly the same.

Linux MD raid supports pretty much just about any combination of the above, so you'd basically achieve the 100% identical result with "in-place" conversion if you had the right settings.

@Bob Nah. I did do a few years of private data recovery work but most of my advanced knowledge came as a result of my uncanny talent for losing my own data. I couldn't afford backups back then.

@AlexSolon One of the RAID cards will go into a Dell R300. The other was actively used in my (now old) desktop.

Main goal: Get that desktop working

Anything RAID related can wait. I just removed those cards to have as little HW as possible.

@qasdfdsaq I'd still be questioning just how robust it is, for something that's supposed to help your uptime (and data integrity). Heck, I'm iffy about moving arrays to new cards of the same family.

But you could also decide to not care, as long as it seems to work for now :P

@qasdfdsaq You could afford the specialised tools to do that kind of recovery, though... how much did that cost? :P

@Bob Well my assumption would be anyone doing it this way would be in a hobbyist/enthusiast scenario .

I moved RAID sets to anew controller... after calling 3ware and getting confirmation that this was supported between the two models.

cough oh, they came with your shiny new linux distro? cough

@Bob Yeah, that

I have two LSI cards in the same server, one's a 2008 and one's a 2116 IIRC, they share the same BIOS at bootup. Even though one supports SR-IOV and the other doesn't :-/

@qasdfdsaq I've found documentation for RAID hardware and software to be ... sparse.

It's both convenient and annoying that they share one BIOS, it's nice because it's an integrated interface that shows drives from both controllers, etc. It's annoying if they're not the same BIOS version and the "wrong" one loads.

It's hard to tell whether some particular attempt at rebuilding, transferring, etc., could potentially break something :\

Linux MD RAID is fairly well documented IMO. And at worst, you can dig into the source code to find out exactly how it works. Hardware RAID has always been a semi-proprietary black box, but there's only so much you can really do with the on-disk format.

Moving on to RAID-Z has been both good and bad.

Often what information is available publicly comes from forums/questions/threads from people who had to dig up their array to perform recovery.

Bad because it's more complex and only ZFS really understands it.

Heh. I like to play with ZFS. But after I got a second desktop up and running (and with it a fresh local copy of all data)

Good because its implementation details is easily accessible, and it's (supposed to be) more reliable overall.

I still wish Windows could run off ZFS.

@qasdfdsaq It can! *in a VM

Yeah, but what I want is reliable, block level snapshots of the OS volume.

You can't even boot off ReFS yet :\

Hometime

@qasdfdsaq I suppose shadow copies do part of that.

Just missing the 'reliable' aspect.

@Bob I still prefer software RAID-1 with ZIL and L2ARC on SSDs :P

@Bob Part of it, yes, but missing the send/receive/clone/easy-to-use rollback stuff.

mirrored ZIL and striped L2ARC

@allquixotic Eh, I just went for the cheaper/simpler option :P

3x SSD was cheaper than 2x SSD + 2x HDD.

@allquixotic I wonder if ReFS is more or less reliable than btrfs :P

GRRRR!!!!!!!!!!!!!!!

sometimes i wish i wasn't a nice guy

are colleagues hot-swappable?

@Burgi only if you have a hot spare

heh!

I have hot spare colleagues, yes.

that doesn't surprise me

@allquixotic ZFS ate my data :-(

i.imgur.com/dS1vdAl.gifv

@Burgi I use 4.6 and 5.2 apertures.

and shoot under 115W 5500K bulb with 36" umbrella

@Boris_yo i'd forgotten about that! :)

Sometimes I take it with me on a rainy day. People ask why umbrella does not have handle.

heh

lol

I always tell it's convertible and on sunny day I can always stick it into sand on the beach.

I remove cover of course which leaves white fabric.

@Burgi I thought 115W should be plenty of light but I should have taken 135W at least. I also think I needto double my configuration and get second bulband umbrella as there's only one side lit. I have video light and I will try to compensate and see how it goes.

I thought pictures are blurry because I shot shiny stuff, like silver and gold plated objects but looks like it's lighting that I am lacking.

@PatoSáinz Meaning that does not matter how close I move it to object lighting will not get more intense?

@PatoSáinz I keep it close to objects but will need additonal lighting on parrallel side.

What are you trying to do? Photography happens to be my trade.

Shoot product photography.

@bwDraco he has some jewellery images that look too dark and aren't shiny

@bwDraco chat.stackexchange.com/transcript/message/27957650#27957650

Low shutter speed needs you are dealing with limited light. If you're on a tripod with a static subject (and that's what I'm seeing), that's okay. You'd prefer to have low shutter speed rather than high ISO.

@bwDraco What's the highest ISO should I use without getting grainy picture tradeoff?

If it's completely static and you have a tripod, as low as possible.

a tripod is a must

The white background is likely throwing off the camera. I'd turn up the exposure compensation.

It looks like you're working with a compact camera, hence the weird aperture numbers f/4.6 and f/5.2. This is going to limit your ability to get good shots.

@Boris_yo: What camera and what lens (if applicable)? I'll need that to give more specific help.

Panasonic DMC G5 with 160 - 12,800 ISO range

imgur has stripped out the camera details

What lens?

G5 is not a bad camera.

Included lens kit G Vario 14-42mm f/3.5-5.6

You should be able to make do with the kit lens but you do need a tripod.

I have tripod.

No shutter release but use 2 sec delay.

wow oracle crap db takes it's own time to create a new database

EyeFi 8GB card really cuts back&forth time and defeats the need of cable connection and SD card removal.

@PatoSáinz does it use some kinda different thing for creating a db

why does it take this long

I don't get it

@Boris_yo 115w CCFL or 115w incandescent?

It's not user friendly, can't find any fucking docs

Looks like it's from 2001

115w CCFL is way overkill. 115w incandescent is nowhere near enough

Okay. I'd place the camera in aperture priority and set the aperture to something like f/7.1 or f/8. That will get you more depth of field and help make up for some of the lens's softness.

@qasdfdsaq CFL

Set the ISO to your camera's base ISO (160). Slow shutter speed is okay given that the camera is on a tripod.

@bwDraco I think lens kitdoes not go beyond fstop/5.6

@Boris_yo Smaller number is faster. You can always stop down a lens, typically to something like f/22.

Smaller number means letting in more light—this is what we mean when we call a particular lens "fast". Larger numbers mean letting in less light, and we call this "slower".

@PatoSáinz are you a DJ?

@bwDraco The reason I do high fstop is to capture more of entire object. Maybe I should do low fstop and then crop the area I want to capture instead?

Faster lenses, especially zoom lenses with f/2.8 (and sometimes even wider) apertures can be very, very expensive. Fixed focal length lenses (prime lenses) can provide apertures as wide as f/1.2 or f/1.4 and are often cheaper, but you won't be able to zoom.

@Boris_yo Then that should be plenty of light, especially on a tripod.

@Boris_yo Use a larger f/stop number. Larger number is smaller aperture.

its a good idea, i would have probably done .music is is rubbish

If you don't understand f/stops and are doing product photography, just set it to f/10 and be done with it.

.music?

@bwDraco @qasdfdsaq Did I mention that I have to turn lens to zoom so I can attain desired fstop?

HAMMERTIME!

With a smaller aperture, you get more depth of field. Past a certain point, however, you may start to see the whole image soften. You'll typically notice this if you stop down past f/11; this is due to an optical effect called diffraction and is the reason I do not typically recommend using f-stops smaller than (or with a larger number than) f/11.

@Boris_yo You don't have to turn the lens at all.

Once again, lenses limit your minimum f-number. You can usually stop down to something like f/22.

Your lens can do anything between f/5.6 and f/20 at any zoom.