Timeline for RAID-5: Two disks failed simultaneously?
Current License: CC BY-SA 3.0
35 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 22, 2018 at 2:22 | vote | accept | Mike Furlender | ||
| Feb 1, 2017 at 20:30 | answer | added | Rickkee Ranton | timeline score: 2 | |
| Mar 26, 2015 at 9:55 | history | edited | peterh |
edited tags
|
|
| S Feb 17, 2015 at 3:37 | history | notice removed | CommunityBot | ||
| S Feb 17, 2015 at 3:37 | history | unlocked | CommunityBot | ||
| Feb 16, 2015 at 3:07 | history | edited | HopelessN00b |
edited tags
|
|
| S Feb 16, 2015 at 3:06 | history | notice added | HopelessN00b | Historical significance | |
| S Feb 16, 2015 at 3:06 | history | locked | HopelessN00b | ||
| Aug 12, 2014 at 12:11 | audit | First posts | |||
| Aug 12, 2014 at 14:36 | |||||
| Aug 11, 2014 at 18:46 | audit | First posts | |||
| Aug 11, 2014 at 18:47 | |||||
| Aug 1, 2014 at 18:32 | audit | First posts | |||
| Aug 1, 2014 at 18:33 | |||||
| Jul 27, 2014 at 14:11 | audit | First posts | |||
| Jul 27, 2014 at 14:11 | |||||
| Jul 24, 2014 at 15:03 | answer | added | Brian Minton | timeline score: 1 | |
| Jul 24, 2014 at 9:36 | answer | added | Halfgaar | timeline score: 2 | |
| Jul 23, 2014 at 13:29 | answer | added | peterh | timeline score: 27 | |
| Jul 23, 2014 at 7:30 | comment | added | MSalters | Then again, when power supplies fail spectacularly (e.g. 12V on 5V rail) it doesn't matter whether you have N+1 or N+2 redundancy. Same applies to fire and other big accidents. Offsite backups are essential, and in combination with N+1 redundancy that may be sufficient. | |
| Jul 22, 2014 at 22:00 | comment | added | Brad | Everyone's comments on here regarding drive failure are correct. Let me add another reason to consider the precariousness of the situation... power supplies fail all the time, and sometimes when they fail you end up frying things. I actually had a hard drive once that had a strange failure, dead shorting the +5v side of the power supply which caused (somehow) 2 other drives to go up in smoke. | |
| Jul 22, 2014 at 21:32 | history | tweeted | twitter.com/#!/ServerFault/status/491697406200020993 | ||
| Jul 22, 2014 at 16:46 | comment | added | usr | If you require fault tolerance you should probably have two independent servers in a mirroring configuration. RAID only mitigates a few specific failure modes. Independent servers mitigate many more risks. | |
| Jul 22, 2014 at 16:43 | answer | added | Payton Byrd | timeline score: 1 | |
| Jul 22, 2014 at 16:18 | vote | accept | Mike Furlender | ||
| Nov 22, 2018 at 2:22 | |||||
| Jul 22, 2014 at 16:17 | answer | added | richardb | timeline score: 4 | |
| Jul 22, 2014 at 16:01 | history | edited | HopelessN00b | CC BY-SA 3.0 |
added 47 characters in body
|
| Jul 22, 2014 at 15:10 | comment | added | Basil | I don't see the write penalty- random writes are cached, and sequential ones don't suffer as greatly from it. | |
| Jul 22, 2014 at 15:05 | comment | added | Sobrique | Problem with RAID 6 and cheap drives is the write penalty. You really do end up with horribly bad performance. But there ain't no such thing as a free lunch. | |
| Jul 22, 2014 at 15:03 | answer | added | HopelessN00b | timeline score: 37 | |
| Jul 22, 2014 at 14:59 | comment | added | Sobrique | RAID 5 gives fault tolerance, but it's a compromise option - you have N+1 resilience, but if you have big drives you have a large window where a second fault can occur. RAID-6 gives N+2 fault tolerance, which is generally considered good (triple failure odds are a lot lower). However, you'll also find the failure rate of more expensive disks (e.g. not cheap SATA drives) | |
| Jul 22, 2014 at 14:58 | history | edited | Basil |
edited tags
|
|
| Jul 22, 2014 at 14:58 | comment | added | pauska | I know it doesn't help much now, but just FYI - the general consensus is to use RAID6 for drives larger than 1TB (atlest when we're talking about 7200rpm). | |
| Jul 22, 2014 at 14:57 | comment | added | MichelZ | serverfault.com/questions/339128/… | |
| Jul 22, 2014 at 14:57 | answer | added | Basil | timeline score: 39 | |
| Jul 22, 2014 at 14:56 | comment | added | Sobrique | Indeed. In an ideal world drive failure rates are randomly distributed. Practically, this doesn't happen - they are usually bought from the same batch and subjected to the same stresses, which means they all start to hit end of life at the same time. A sudden shift in loading can quite easily tip several 'over the edge', even before you start looking at unrecoverable error rates on SATA disks. Anyway - I'm afraid the bad news is, unless you can get one of those drives online, it's time to get the backups out. | |
| Jul 22, 2014 at 14:56 | comment | added | Mike Furlender | Interesting. Could you perhaps direct me to some information about which configuration IS recommended? We require fault tolerance and fast I/O. | |
| Jul 22, 2014 at 14:54 | comment | added | MichelZ | Yeah, big sata disks tend to do that. (Rebuilding 3 TB takes many hours while you are exposed to double-failures). So this is expected and it's why RAID-5 using such a configuration is absolutely not recommended. | |
| Jul 22, 2014 at 14:48 | history | asked | Mike Furlender | CC BY-SA 3.0 |