So, If you’re reading this, you’re exploring the possibility that your RAID 5 COULD fail. This is very annoying because RAID devices are used to avoid this problem. However, if this HAS happened to you, we’re sorry for your loss (of data). In this article, we’ll explore how we can limit and avoid this from happening in the future. He’s a whole handful of handy advice for you RAID 5 users at home.
- Take it Slow
Okay, so your RAID device is inaccessible for some reason. The device could hold a plethora of data, and it’s vital to get it back online and accessible, maybe even for the good of the company (in this theoretical example). Yeah, maybe then it’s feasible to have a tiny panic. You need to keep in mind though, that panicking isn’t very efficient. Hitting buttons and plugging things in and out without really knowing what you’re doing can be detrimental. Just relax, and avoid any actions if you don’t know what they mean. - Device Delicacy
RAID Cards are clever. They’re built by companies who care, and they’ll hold information to what may be happening where you may not know. If it isn’t completely dead, it can start up even when faulty. If you try doing something though, and it tells you can it could cause a data loss, you need to take the warning as a… warning. Don’t do something if the card tells you not to. That way, you would actually lose things where you could have otherwise recovered data, whether by Synology Data Recovery or otherwise. - From Digital to… Manual
Box-Booklets from technology can sometimes become nothing more than a coffee placemat or left where they were found in the box. Like said in the previous tip, the companies that manufacture RAID 5 Devices will care about their customer support, and the manuals they supply are very comprehensive. Error messages can be described in these manuals and describe what the issues are. If you never gave the book a chance earlier, please give it a read and find the issue you have in the book. Oh, another thing. Did you throw it away…? If you look it up online, the company you bought it off will have a manual online too. The future, eh! - Someone out there Knows More!
It can be common that there is a designated person in your house who does the ‘tech-stuff’. However, there are some issues that can’t be understood by them. Even if you contact RAID developers themselves for help, some things can’t be answered or explained well over the phone. There are trustworthy third-party tech aid out there with very skilled staff and great advice. If you think all is lost and there’s no hope, get online and look for RAID Data Recovery experts. Even if you’ve run data recovery and failed, they can still work wonders, so don’t lose hope. - Rebuild WON’T restore
Raid Rebuild software can be an incredibly useful tool for those savvy in the RAID ecosystem. However, to the average user, ‘Rebuild’ may sound like something else, restore. THIS WON’T HAPPEN. Before you use tools, you need to understand what their purpose is, which is a great rule of thumb in most cases. A RAID 5 Rebuild’s purpose is to collect a current data set from a card, on a degraded array, and restore the redundant data. You can think of this as polishing your shoes. It’s making it sturdier for the future and cleaner overall. If you have corrupted data though, you could be creating newly redundant arrays full of Corruption! This is why you CAN’T click rebuild without know exactly what it does, and if you have corruption, don’t use it. - Back-Up Blues – Test, Test, Test
Imagine another situation. You have a few hard drives in a RAID 5, so you go to replace both drives. Brave. You remove the previous volume because you have a solid back-up. Then, you restore the huge cache from the solid back-up ONTO the RAID array. Only then, you find out that the back-up was also inadequate in some way. This issue is long, frustrating, and detrimental in some work environments. After all, who knows if the back-up is also corrupted, eh? You can avoid this problem quite easily, and although it takes a little bit of time to do, in the long-run, it’s definitely worth the time or the money spent. If you test your backup on a storage array separate to the hard-drives that have failed in the original failed array, the problem is reduced. That way, you don’t rush to restore over your working drives with an old or faulty data-set. Then, look to source a new array, test the back-ups, and then you can go about sorting the dead array. Annoying in the short, but very much worth it in the long run. - Don’t RMA OR Re-use Drives from a Failed Array (…until a verified back-up is complete)
There are some people out there who aren’t as knowledgeable in the tech-field of RAID. Fair enough, it’s a small ecosystem. However, make it common sense from this day forward to never try using failed array drives in new rigs. This creates an issue of the RAID rig running degraded for a LONG time if you can’t remember that you’ve done this. It causes a huge headache and is easily avoided by using fresh drives, or verifying back-ups. - Detection = Decent
Yes, you may have a problem with the drives in some cases, but that doesn’t necessarily mean that the RAID card is faulty. If you plug in the device, and it reads alright, being detected, then the RAID card is okay. It’s good to know this, as it saves you from having to shell out money to get a new one. You can instead investigate another way to recover your files. - If you use a Hot-Spare, Stay cool
Many tech-savvy people will know what a hot-spare is. It’s a fresh and clean drive lying about in wait to be used if something goes wrong, Commonly in RAID groups. However, If you place it in and it doesn’t engage in the storage away, DON’T THINK THAT IT HASN’T WORKED. You can verify that your back-ups are both current and consistent on another separate array to the failed RAID array before you utilize ANY of the failed array’s drives, which includes your hot-spares. Don’t be fast in assuming that your hot-spares don’t work, because they’re very useful kit! - Offline, Online.
When one of your devices goes offline, there most definitely is a reason for it. If it doesn’t want to go online then, don’t force it online. If it seems offline, it probably means that it was failing, and quit while it was ahead. There’s a lot of technical jargon to back this up, but we can explain this well here. Unless you’re confident that you know when it was removed, and no that no essential/’critical’ files were updated after that, don’t risk putting it online. If not, any larger files that have been created are guaranteed to be ‘full of gaps’ as it were and be useless data.In these situations, your operating system will see these issues and try to resurrect them. Don’t do this! It seems promising, but the OS doesn’t know that these corruptions were not to be fixed. They were inconsistent artifacts, from plugging stale drives into the arrays. Repairs to these then can completely destroy the current data across all of the array drives, not only the stale one. This is detrimental. If things are offline for a reason, don’t ignore the reasons! - Know the data if you want a New Config
Some users of RAIDs may not know exactly what the corners and walls are, meaning that they won’t know everything there is to know about their RAID device. If you’re trying to set up a new configuration, you’ll be supplied with a few fields of information to know. Do Not guess this information. This is Parity, Stripe, Rotation, and Offsets. If you guess this incorrectly, this could become a huge problem. The computer may see file system corruption and start running repairs, which can wreck the files. It appears corrupted because you have the incorrect configuration on the device. After those ‘repairs’ are carried out, it’ll be too late to access any of your files, and you may have gone too far down the rabbit hole to get anything back. - Don’t Plug-and-Play with Drives!
What we mean by this point is that sometimes when people think that one of their arrays is faulty, they’ll take it from the bay and plug it in with a USB port, to attempt to run RAID 5 Synology Data recoveries. There are many tutorials online and it makes it a reasonable and accessible course of action. However, it can also be a very risky one. The operating system, when you plug in a USB chassis on its own, won’t know that it’s looking at RAID 5 Specific data. It will attempt to automatically fix corruption, and the drive will show up as empty space. You don’t want this.
Again, like covered earlier, trying to ‘fix’ the supposedly ‘corrupted’ drive in this way can lead to massive data loss. Third-party data recovery software won’t be accommodated for RAID 5, and even if it was, RAID Drives typically save across multiple drives, so you would only have fragments rather than full files. This is one huge ‘yikes’, and it’s ill-advised.
At the end of all of these tips, it can seem scary to even dare using RAID 5 equipment, but the benefits are also huge. There’s a great tech community around this software, and everyone aims to help everyone else out. So, it’s important that you follow these tips well, and we hope that you avoid any unnecessary data loss through them. We wish you well going forward!