RAID

Data redundancy and parity is a disaster waiting to happen?

You fucking what?

>>61701876
fuck off memester

>>61701890
Being retarded is fun, huh?

>>61701671
Raid is yet another tool in the kit of the competent sysadmin... The same way you can use a hammer to build a pretty little birdhouse or smash your thumbs to shit just as easily.
Raid is not a backup. Raid is not fault-tolerance. Raid is high availability. All it does it make it take longer to lose all your shit. It's not an excuse to have shitty backups, shitty DR plans, shitty attitudes about data security and archiving.
Be smart. Use the tools you have responsibly.

>>61701671
RAID 0 maybe.

>>61702021
Raid 1 is LITERALLY a backup, you fucking idiot.

not using RAID is like saying you don't need insurance

enjoy the day you get fucked

>>61702041
Who uses 1? 6 or 10

>>61702071
10 is literally a backup too you fucking retard.

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>>61701671
>he doesn't put his fish in raid 1

RAID is an old meme

erasure coding is better

use ceph or something equivalent

>>61702041
No it isn't. RAID1 is redundancy.
A backup is not stored in the same machine as your working data, preferably not in the same location at all.
With RAID1, a harddrive or two can fail and you'll be fine. A backup should be fine if your house burns down.

>>61701671
Raid has been replaced by the cloud

>>61702041
No, it's not. Treating RAID like backup is a recipe for disaster. A backup is something offline and preferably offsite. The point is that no matter what happens to you system, the backup is fine. There are a lot of things that cause bad things to happen to your RAID array.

>>61702041
>Raid 1 is LITERALLY a backup, you fucking idiot.
^^^ these are literally the people you browse /g/ with

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>>61702114
and what is data in the cloud stored on?

>>61702150
Clouds, duh.

>>61702021
This

RAID is not for backup

RAID is for keeping your shit running

>>61702137
>>61702107
>>61702143

>i get to define words differently than what they actually mean based on my beliefs regarding what is sufficient for data preservation

It's literally, by definition, a backup. Fuck. Off.

>>61702180
The point is that it is not a backup STRATEGY. It is a point solution for particular failure modes and a temporary one at that.

>>61702220
I am more than aware of the fact that it is not an ideal or even relatively decent backup strategy, but it is LITERALLY, BY DEFINITION, a backup.

>>61702156
An array of clouds, if you will

>>61702235
Perhaps by the strictest definition of backup, but not by how most people define a computer backup.

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>>61702246

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>>61702235
Mirroring =/= backup. A backup is a mirror, yes, but not the other way around. A backup consists of more than just a mirror. Thus, they are mutually exclusive.

>>61702041
No. If data corruption occurs, it happens on both at the same time. I've seen it happen before my eyes.
No raid is a backup. A backup is a separate copy that is not connected to the working set in any significant way.

>>61702041
RAID 1 is for redundancy. if one drive dies, the system is still up and running without any downtime.

rarely used example: if you overwrite an important file with all zeroes on one drive, it's gone on both drives. you can't say the mirrored drive was a "backup" that saved your ass. on the other hand a true offline backup copy you had from a tape (or cd or usb drive) can be restored, because it's a true backup. see the difference now?

sorry for the longwinded post. the word "redundancy" may not capture the whole essence of the process.

>>61702313
>>61702311
>>61702308

>i get to define words however I want regardless of whether or not that's what it means as long as it fits my argument

okay kids, have fun in the real world when you grow up

>>61702180
https://en.wikipedia.org/wiki/Data_redundancy
https://en.wikipedia.org/wiki/Backup

RAID1 is not a fucking backup. It is redundancy.

http://www.dictionary.com/browse/backup

 Computers.

    a copy or duplicate version, especially of a file, program, or entire computer system, retained for use in the event that the original is in some way rendered unusable.
    a procedure to follow in such an event.

In the case of RAID1, you have 2 (two) (or more) originals. If ANYTHING other than a harddrive failure happens to your data, it happens to both originals. If your RAID controller for some reason freaks out and corrupts the data, both originals get corrupted. If you install ransomware, both originals get encrypted and you're fucked.

It is literally, by definition, not a backup. A backup, by definition, is a copy of the original data stored away from the live data.

>>61702180
RAID is not a backup and should not be a replacement for backups.
It is for redundancy or performance.
You might not have to restore from backup if the array can be rebuilt but that does not mean it is a backup.

>>61702308
a backup is more of a snapshot in time. a mirror is just a copy in real time.

Raid: (Except 0) allows creation of large data volume with some protection so if you lose a drive (or two drives depending on raid type) you can still backup your data before the whole raid array (another drive) fails. In the age of large data volumes it's not worth the risk of doing a rebuild of the existing array, just backup your data and recreate the array from the ground up,preferably with larger capacity hdds than what was used with the old array. Large business typically have two or more identical file servers in cluster mode or DFS so if one server is down for whatever reason the others take over and the average joe user is none the wiser, they can still access the files no problem. Small home servers/small business the cost to build two (or more) servers and keep them on 24/7+ keep backups all going is just two much.

>>61702180
Wrong.

Backups primarily refer to the filesystem layer.

RAID is a technology that operates independent of filesystems on the block layer. you could very well have a boot partition that you'd prefer to retain if met with a hardware failure. How are you going to recover from that easily with a backup?

>>61702021
>>61702171
>>61702041
>>61702059
>>61702041
>>61702180
>>61702341
>>61702335
>>61702313

RAID
is NOT
a BACKUP

>>61702335
You are wrong. Adding more copies of the original that are written to at once doesn't give you the ability to "roll back" to a previous version, which is the entire point of having backups.

>>61702396
RAID IS NOT A BACKUP SOLUTION

gotta say the whole thing 3 times when you pray to the parity gods bro. dont fuck up the incantation.

>>61702396
raid is a backup until you fuck it up and lose everything, obviously!

>>61702396

that's exactly what I said in >>61702313
I was pointing out the difference between what RAID 1 is used for (uptime) and a true backup (immune to simultaneous deletes from both copies)

ugh

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Say I run a hypervisor machine with a RAID 1 volume with a virtual server on it.
I decide to do something boneheaded on my like doing a recursive delete on the database directory, something just completely braindead. You never know, people do this shit all the time.
So now I want to un-do it. Well, I'm a moron and I didn't enable snapshots on my VMs, so I can't do that.
What protection has my raid afforded me? Has it provided me with a "restore point"? Nope. It's a copy of the same fucked up data.
This is the thing you have to remember. Most data loss is because of malicious intent or human error, not hardware failure.

RAID IS NOT A BACKUP.

This is a great thread, I'm gonna use RAID now to backup all of my servers. Thanks /g/!

>>61702536
Be sure to use RAID 50 with big disks for thos extra IOPS

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>>61702335
The literal raid fucking wiki!!!!

>>61702041
>>61702089
We use large RAID arrays but frequent additional backups are done too (typically to tape), which are stored off site. As >>61702021 it's another tool.

>>61702114
This is illegal in a lot of places if you're handling sensitive data.

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>>61702335
>RAID is a backup by definition

>>61702396
You can use RAID1 for backups.

Just pull out one of the disks and take it home with you.

What is back up, amirite?
Let's do nothing while we finnally get a monolithic solution for storage.
Or we can go with what we have, paralelism and if it go wrong (it might go wrong!) we have something called BACKUP PLAN, you know, the Plan B?

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>>61702041
>user error on RAID1
Ah, yes, let me just consult my second drive for that copy of the file...

since RAID isn't a backup, does /g/ approve of ZFS?

>>61703089
And then when you put it back in wait 15 hours for the plex to resync.
Tried that shit... Nope. Bad idea.

>>61703257
where can I read more about these things that are popping up replacing raid and stuff, like zfs raidz and other stuff?

>>61703348
zfs isn't anything new- been around since the mid 2000s. freenas.org and wiki would be a start.

>>61703257
ZFS is tight. Make sure you read up on it to the point you can fix it if it fucks off, but it's pretty damn stable.
Gonna want a machine with ECC memory. Some people say it works fine without, but who do you want to trust: a. world class engineers at Sun Microsystems, or b. neckbeards that have no idea what they're talking about (me).

>>61703348
Look around on the tiny storage boards, they're out there but hard to find. Wendell did a good video about it a while back that's worth checking out as an introduction to copy-on-write.
BTRFS is up and coming, but nowhere as stable and hardened as ZFS. It's way better than "last-gen" filesystems/volume managers (cough-cough microsoft ReFS) but still a ways away from what I would consider stable enough for production.

What if I my backup is in a RAID 1 array?

what do you guys recommend if i just want to create a drive pool that can be backed up easily

>>61701671
RAID is for the enterprise. It NEVER reduces the need for backups. It can deliver increased uptime.

>>61701671
yes.

ceph and other software like it are much better than muh raid.

don't fall for the meme.

>>61703577
ceph dipshit.

raid is for retards who are living in the fucking 90's.

i'd only use raid for like small ass storage. like maybe a few terabytes and raid5 with hot spares. very unlikely that a small raid5 array of small disks will take forever to rebuild.

for yuge data though, just use ceph. erasure coding is way better.

my RAID 0 array is failing...

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RAID 0 is completely fine

>>61703533
Then you're probably just wasting time and money.

>>61703945
Yeah, it only multiplies your drive failure risk by the number of drives in the array. Nothing to worry about.

>>61704005
this sounds pretty good
20% * 20% = 4%

>>61704033
You didn't do well with word problems in school, did you?

>>61704104
No, but I was worse with plain written equations that used trigonometry or other high school stuffs
I got what you meant now though, 20% * 2

>>61703945
>1 soft error in metadata bricks your entire NTFS (lmao) filesystem
Okay.

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>>61703533
It better have checksums to regenerate damaged data...
Pushing corruption to backups is a real risk.

>>61703257
I use it as my root filesystem on every machine I own.

>>61703945
As a scratch disk, yes.

>>61701671

>implying anyone here would know how to configure a SAN

>>61704355
>64 hours to scrub
I'm glad I used mirrors instead

>>61701671

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>>61701671
This is what happens when kids are allowed near the internet
>RAID it's a meme, right?

I despair.

>>61702785

>>61707126
Nice kaede.

>sorry you have brain cancer you're gonna die
>family is in tears
>don't worry everyone i have my brain on RAID 1 it's all backed up
>they all all look at you simultaneously
>ITS NOT A BACKUP
>they unplug the brainulator and kill you

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>>61708246

>be sysadmin
>have RAID
>drive fails
>"it's fine, my data is backed up thanks to RAID"
>rebuild array
>everything is fine
>office burns down
>topkek

>>61707126
Nice background pic. Got a link?

>>61701671
just make real backups and stop wasting terabytes of storage on raid.