You can place new disks in your nas at two moments, when all disks are full or if a disk is defective. In either case, you have to realize that a hard drive in a NAS is part of a complex storage system. Just taking out one drive and putting in another is not a good idea. Replacing disks in a NAS is done according to certain rules. But with the right knowledge and information, you can replace a disk in your NAS in no time.
A nas is made to quietly do its work somewhere in the house. More than electricity and a network cable is not necessary. And furthermore, you only need to periodically install an update or you may want to install a new package yourself. There are two cases in which the NAS does require more attention, and that is if the storage becomes full or if the storage is faulty. Both are situations where you need to get started right away to replace the drives. A job that nobody really looks forward to, if only because it costs money and there is always the risk of data loss. And no one wants to experience that last one. In this article, we will show you several things to do to set up your NAS, based on the menu structures of Synology and QNAP, which are very similar. Of course, other NAS manufacturers offer similar options, but they can be called slightly different.
01 Receive signals
Because a NAS is usually out of sight, signals that there are problems with storage often go unnoticed for a long time. However, speed is important because the sooner you fix the problem, the more likely you will not lose any data. A NAS only has a limited number of resources to get your attention. The first is by sending an alert via email or text message, but this only works when it's previously and correctly configured. And that is often not the case. What always works are sound and light signals. If the NAS really needs attention, first of all it emits a clear beep every few seconds and also causes the HDD LED to blink orange or red. If you see or hear these warnings, take immediate action.
02 First analysis
First of all, log in to the web interface of the NAS. You may immediately see a message about the problems, you may need to check the part first notifications or Logs to open. Look at the Faults and Warnings with regard to storage. Then open the storage manager if it Storage Management and look at the specific information about the storage configuration. The following applies: 'just watch and don't change anything', because especially when it comes to a defective disk, any change can cause further problems for the system. Also check the S.M.A.R.T. status of the individual disks. SMART. is a system that reads the many counters of a hard disk and assesses whether a hard disk is still healthy. Often S.M.A.R.T. problems arrive before the storage is actually affected. Then you are well in time to intervene. If the nas is already in trouble, via Control Panel / General you can turn off the sound signal.
03 What not to do
At least as important as what to do when there are problems with a NAS is what not to do. To protect the data on the NAS, you should limit the activity of the NAS as much as possible. Chances are that when you log in to the NAS again after a longer period of time, a firmware update will be suggested: don't do it! Updating packages: don't do it! Installing new packages: don't do it! Anything that doesn't help replace the drives or restore the storage has to wait. First the NAS must be stable again.
04 What does it say?
Before going any further, it is important to know if there are any files on the NAS that you do not want to lose and are not located anywhere else? If so, then you really should do everything you can to avoid data loss. If the storage space is healthy, but just too full, you can first try to delete unnecessary files. Perhaps after a good cleanup, the entire disk upgrade is no longer necessary or it can be postponed for a few months. But if the storage is endangered by a failed hard drive, you should definitely not clean up, because any write movement for the failed hard drive can mean the real end. Therefore start the traffic jamstation and go through the folders and files on the nas. What is it and how important is it. If the NAS is still healthy, you can also have the NAS inventory inventoried via the Storage-analyzer or a similar function such as System Resources / Storage source / Storage area at QNAP.
05 Is there a backup?
We recommend making a backup of the data on the NAS first (see also box 'Backing up the NAS?') before you start working with the NAS drives. This is especially true when the NAS contains unique information, files that you don't have anywhere else. If the NAS is healthy, but only the storage is full, making a backup is definitely advisable. If the storage in the NAS is faulty or a drive is nearing its end according to the S.M.A.R.T. information, creating a backup is a trade-off against the risk that performing a backup will make the NAS even more unstable. Fortunately, there are more and more options for backing up a NAS, for example to an external drive or a Tandberg Data RDX QuikStor, but also the cloud. Some of these backup functions work directly from the operating system, others require you to install an additional package. If you had not yet installed such a package at the time of the problems, it is not wise to do so if the storage is corrupt or defective.
Backup the NAS?
The best measure against data loss is to have a backup even with a NAS. A NAS backup sounds illogical to some people because they even see the NAS as a backup. But that's just not it! The 3-2-1 rule applies to backups: 3 backups, on 2 physically different media, 1 of which is outside the home. If the backups of all PCs and other devices are only on the NAS, then you do not meet rules two and three of a good backup. You can solve this by also backing up the NAS, the data will then be stored on a second device that can also be stored outside the home.
06 How much storage space
Although we are not yet ready to swap drives, it is necessary to know how much data is on the NAS. The rule is that the new disk (or disks) from the NAS should provide at least the same storage capacity as there is now. Smaller is not possible, and the same amount of storage only in the event of a failed disk, although you can also manage with a larger disk. If you want to know how much storage space is now and is being used, check the section Storage Management or storage manager, or use the Synology Storage Analyzer or at QNAP System Resources / Storage source / Storage area for more insight. To see which disks are in the nas, look at Storage Management / HDD/SSD or Storage and storage moments / Storage / Disks.
07 Data protection
The next thing to find out is the arrangement of the storage space on the NAS and whether additional protection of the files on the NAS against hardware failure such as a failed hard drive has been chosen. When configuring the storage space on a NAS there are three options: jbod, raid0 and raid1 and higher. With jbod and raid0 there is no additional protection against hardware failure. If a disk breaks, the entire storage capacity is lost and with it all files. With jbod and raid0 you can't just replace one disk with another. This is more or less possible with raid1, raid5, raid6 and raid10. These are all raid variants where the data is stored on the drives in such a way that if one of the drives breaks, you don't lose any data. But that only applies to raid1, raid5, raid6 and raid10. If you have data protection, it will soon make it possible to replace disks one by one with new or larger ones. Without data protection, that option does not exist.
Automatic raid
With raid you can protect the data on a NAS against the failure of one or more hard drives. For that you have to choose the right raid variant and that is not always easy. A number of NAS manufacturers therefore offer a 'smart' raid option in which the NAS itself determines what the best raid is based on the available disks and where it is also possible to use disks of different sizes. At Synology this is called SHR (Synology Hybrid Raid), at Netgear X-RAID. This works fine, but with a defective disk you feel less certain which raid has been chosen by the nas and what you have to do to replace the disk. If you have not yet replaced disks after the first configuration, you can almost assume that raid1 has been chosen for two disks and raid5 for four disks and more. If you need to restore the raid system, log in to the NAS web interface and check the raid format at Storage Management or storage manager and follow the directions provided by the NAS to restore the system.
08 Remove disk
In order to expand or recover the storage capacity in the event of a disk failure, one or more disks will have to be removed. It is important here whether the NAS is 'hot-swappable' or not. You can check this in the specifications of the NAS. If the NAS is hot-swappable, you don't have to turn off the NAS to remove the failed drive and insert the new drive. If the NAS is not hot-swappable, you must first log in to the web interface and neatly disable the NAS via the menu. If the NAS is completely turned off, remove the failed disk, insert the new one and restart the NAS.
09 Raid0 and jbod 'extend'
If you want to expand the storage and a jbod or raid0 format has been used, the drives must be replaced with new ones with more storage capacity. Once you take out the first drive, the NAS will lose all storage capacity and access to all files. Once the new drives are in place, it's a matter of rearranging the storage capacity, this time preferring a format that offers additional data protection. You can do this when the NAS is hot-swappable while the NAS is turned on, but since the entire storage is inaccessible anyway, you might as well disable the NAS first. Number each drive you take out of the NAS corresponding to the position the drive occupied in the old configuration.
10 Expand Raid1 and above
If the nas is equipped with raid1 or higher, then there is data protection. This works to your advantage. You can replace one drive at a time with a new one and then let the NAS restore its storage capacity. Start with the drive with the smallest storage capacity or if the drives all have the same capacity, just put the first one in the NAS. After the new drive is inserted, start the storage volume recovery process. click on To manage / To recover and follow the steps of the wizard. The NAS will erase the disk and then restore the raid system. The latter can take hours and sometimes more than a day. Let the nas do its work and wait patiently for the recovery action to be completed. Only then do you change the next disk, again the smallest one or the next one in the nas if they are all equal. Only when all disks have been replaced and the raid has been restored again, you can use the full new storage capacity.
11 Faulty disk at raid0 and jbod
If you don't want to expand the storage capacity, but a disk has failed, the remedy for raid0 and jbod is very simple: cry out and start over. Raid0 and jbod offer no data protection, so once a drive is really broken, all storage is lost. The procedure is therefore the same as for the expansion, except that you can now suffice with replacing only the defective disk. If the discs were bought at about the same time, keep in mind the possibility that a subsequent disc may soon give up the ghost. Replacing all drives may then be the wiser option.
12 Faulty drive on raid1 and above
The procedure for a failed disk in case of a raid1 or higher is the same as for expanding the storage. Only now you don't replace the smallest disk, but the defective disk and you can suffice with a disk of equal storage capacity. Once the disc has been inserted, you must now also start the recovery procedure via To manage / To recover and any further action must wait for the volume to be restored.
View through Windows
Disks in a NAS are often formatted with an ext3, ext4, xfs or btrfs or other format. The nas (Linux) can handle it just fine, a Windows computer cannot. Removing the disks from the NAS and connecting them to the computer via a USB docking station or a SATA port on the motherboard and copying the files is not an easy thing to do. This requires software that can read the unknown disk format and understand the raid information. Such software exists, for example UFS Explorer, ZAR and Home NAS Recovery. The software is not free and we have no experience with it ourselves. To use the software, the disks must be removed from the NAS. To do this, switch off the NAS and very important, number each disk that comes out of the NAS in such a way that the entire set can always be put back in the correct order.
Help desk
Data loss is worse than a damaged ego. In case of doubt or uncertainty about a problem with the NAS, please contact the helpdesk of the NAS manufacturer. They have a lot of experience with problems that may arise. In addition, a number of NAS brands offer the option of having a technician remotely monitor your NAS and repair things. At Synology you can arrange this via the Support Center, QNAP has the Help desk-function.
