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The combination of RAID0 redundancy, an ext4 filesystem, a Linux 4.x kernel, and either Debian Linux or Arch Linux has been associated with data corruption.
El Reg reports EXT4 filesystem can EAT ALL YOUR DATA
Fixes are available, one explained by Lukas Czerner on the Linux Kernel Mailing List. That post suggests the bug is long-standing, possibly as far back as the 3.12-stable kernel. Others suggest the bug has only manifested in Linux 4.x.
[...] This patch for version 4.x and the patched Linux kernel 3.12.43 LTS both seem like sensible code to contemplate.
[Editor's Comment: Original Submission]
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Running an ext4 RAID0 with a Linux 4.x Kernel? Better Spray for Bugs
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Whenever I feel like exercise, I lie down until the feeling passes.
(Score: 3, Interesting) by gman003 on Tuesday May 26 2015, @06:05PM
Does anybody really run RAID0 anymore? The canonical use case was for fast throwaway partitions like /tmp, or even swap space, but now that RAM is so plentiful, people run those partitions on ramdisks instead. And if it's too big for a ramdisk, there's SSDs. Is there anything that a) needs higher I/O performance than a single drive, b) can tolerate data loss, and c) is too big to fit in RAM or an SSD?
I know there's some high-capacity SSDs that secretly RAID0 together two smaller SSDs rather than use a controller that can natively handle that much flash, but that's not really relevant to this sort of issue, and is a dying practice anyways.
(Score: 2) by kaszz on Tuesday May 26 2015, @06:42PM
Perhaps in situations where you have multiple layers of disc packs? Like RAID 5 which in turn is clustered as a RAID 0 volume etc.
(Score: 2) by richtopia on Tuesday May 26 2015, @07:18PM
I have some tools running RAID0 WD Raptor drives - they were built before SSDs were readily available and the policy is to maintain the original hardware profile if possible.
Don't get me wrong - this is a silly point of failure for a million dollar tool, but legacy is important!
(Score: 4, Interesting) by VLM on Tuesday May 26 2015, @07:28PM
Its nice for huge logs, both higher level stuff and packet sniffy at "system wide" levels not just monitoring one machine.
How often is this important, well, practically never. But its nice enough to have.
This rapidly runs into the ram limitation that WTF are you doing if you generate more than dozens of GB of raw data, and thats nice that you gathered it but now what do you propose to usefully do with it in a reasonable period of time? So I can build something bigger than I can find a productive use for it.
I always figured it would be useful for a really wide broadband SDR, no decimation, nothing just slam gigs/sec onto a drive for later analysis. That would work pretty well for RAID0.
You can also do stupid nerdy stunts. Floppy drives can't read fast enough to play mp3 files (most can't sustain more than 50K or so) and usually don't store enough data anyway, but if you take a thundering herd of them and plug like 8 external USB floppy drives into a pile of USB hubs and RAID0 them together then its sorta usable. Its not nearly as visually impressive but you can do similar "stupid raid tricks" with USB flash drives. Supposedly it takes "a lot" of parallel USB flash drives to record live video, at least back in the old days when they were slower access, maybe they're fast enough now.
If you ever get bored, and have a pile of USB flash drives or floppy drives, you can do all kinds of lunatic things with RAID. Its "hilarious" to set up a raid5 and then push the eject button of a floppy drive and then hot-add it back in. I guess on a rainy day I can be easily amused, but it seemed fun at the time.
A little google work shows I'm not the inventor of this fine idea, there's scant online reference to 127 usb floppy drive arrays out there. That would be a beautiful sight to behold.
(Score: 2) by slinches on Wednesday May 27 2015, @06:29AM
I just configured a new FEA workstation with a RAID0 array of 10k rpm SAS drives. It's actually being used as the primary active data drive, but the configuration was selected to be an effective working directory for analysis runs. Some of these runs can require several terabytes of I/O with results sets in the hundreds of gigabytes, so high capacity and speed are paramount. Redundancy is then handled by running daily scripted rsync operations to regular SATA drives.
This setup becomes roughly equivalent to RAID10 in terms of data security except that it's asynchronous, so a drive failure could cause the loss of some recent data. The benefit of accepting that risk is reduced cost, increased usable space and better write performance relative to RAID10 with same number of disks.
For example:
8x 1TB SAS 10k rpm drives in a RAID10 array gives 4TB of space with 8x read and 4x write speeds (cost $400 x 8 = $3200)
6x 1TB SAS 10k rpm drives in RAID0 gives 6TB of space with 6x read and write speeds + 2x 3TB SATA drives (cost $400 x 6 + $150 x 2 = $2700)
(Score: 0) by Anonymous Coward on Wednesday May 27 2015, @07:13AM
I believe RAID0 is still big in video editing.
All those gigabytes of RAM... They can hold a couple of uncompressed frames.