Re NAS for storage only. I gather this would be spanning data and some parity files across a number of Hard discs.
Basically, yes but not as files. A RAID volume uses the harddisks as raw devices, not as formatted NTFS volumes your pc can work with. The entire array becomes a volume your pc can work with, but below that software will split up the data in data blocks and parity blocks, this process is transparent to the user.
When a RAID 5 NAS device (with 5 x 2TB HDD)with is plugged into the pc, the pc would see it as one volume...ie an 8 TB "X" Drive, or whatever drive letter?
A NAS is not plugged into your pc, its connected to your local network. It requires some setting up. Basically, when you turn it on for the first time it gets an IP address from your local router or you need to set it up with an ip address so you can access it. You can then access it through a webpage, setup storage volumes, create network shares and setup permissions.
Here's an example of how you would setup volumes on a Synology. In fact, Synology has some nice articles you could browse to get an idea of how their software works. The only thing I couldn't find on their site was an initial setup. Once setup, you can create a mapped network drive on your pc(s) to the shares you created on the NAS. These shares can be an entire volume or individual folders you created on a volume.
Re NAS as a file server.
Whether you use it for backups or as a file server, the mechanism behind is the same. It is setup the same. You might choose to use no or less redundancy but that's about it.
An exception would be if the NAS vendor supplies special backup software that doesn't require shares but accesses the NAS 'directly' but I never worked with that and I don't even know if that still exists (I think my old QNAP had something like that, never used it. I could press a button on the NAS and a backup would automatically start on the pc it was linked with).
You would have a similar arrangement as a primary storage device (with perhaps a greater redundancy).You the backup one to the other.
I never meant to suggest you need to get 2 NAS devices, or maybe I'm not reading you correctly. It's possible but its also a little overkill if you ask me. A more practical solution would be to setup your NAS with 2 volumes, a 3 disk RAID 5 and either a 2 disk RAID-0 (no parity) or RAID-1 (mirrored) for backup purposes. You would have redundancy for whatever you store on the RAID 5 volume and place your backups on the other volume.
But I can already hear some people raging, because its not considered best practice to store your backups on the same device as the rest of your data. If that device burns out it could destroy both data and backups, or if it gets stolen, same story you loose both. Best practise dictates you store your backups offsite, but really, how far you want to go is up to you and how important you consider your backups. I'm aware of all the rules and regulations around making backups and storing them but that isn't practicle or affordable for home use so compromise is made. What and how exactly is up to you. It's your data, you know how important it is to you. Consider the concequences when it is lost and then you can determine how and where you want to store your backups.
There would be no use of server software on the NAS for file serving.
Correct. A NAS comes with everything you need to set it up for file sharing. Depending on the vendor, it may come with additional features such as DLNA server, print server, web server. Have a look at the product features from different vendors to get an idea what they can do.
I gather that beyond the above implementation you could set it up as a file server probably utilizing DLNA or some such. I am wondering how this dovetails with JRiver MC? I gather MC can "pull" the files from a NAS but this would be using the NAS server software rather than JRiver server software ?
JRiver is both a client and a DLNA server. If you setup a NAS a DNLA server, MC can use it as a client and stream music and/or movies from it. Personally, I would rather use the NAS as a fileserver and let MC be the server and client for media, but its entirely up to you. I'm not sure how tagging and file management would work if you setup your NAS a DLNA server for MC though. I think the connection is read only.
But, I'm not really the best person to answer this, I have hardly any experience with DLNA. I suggest you search the
Media Network topic and if you have any questions, post them there.
Finally,on a different note, why isn't a copy with a sync tool (or perhaps imaging software ? ) a backup ? All the files are duplicated to another place.....and can be restored to the original location if required ?
Thanks again
David
Good question, glad you asked
. Imaging software is considered backup, a file sync is not.
When you copy a file or folder in Windows, a number of things can happen, depending on the source and destination location. But first you have to realize that a file is more than its contents. Agreed the contents is by far the most important aspect but that doesn't mean the rest should be ignored. A file has attributes, an owner and permissions. Attributes define basic parameters of a file or folder. It can define a file as a system file, as hidden, as read-only and whether its changed or not. This last one is an important one, its called the 'Archive' bit. The archive bit is used to tag a file as changed, the OS does this automatically when the contents or other attributes or of a file are changed (including permissions and owner). When a file is backed up or copied, the program resets the archive flag on the source and uses this bit to determine whether the source files have changed since the last time they were backed up or copied.
Another aspect of a file or folder are the owner and permissions. The owner is the user account that initially created the file or folder. Permissions determine who can read, write or modify files and folders, even if you have only setup a single user account on your pc (there are always multiple user accounts as the OS itself creates several).
When you copy a file, attributes, the owner and permissions can change depending on the source and destination. For instance, the read-only attribute is lost during a copy and the archive bit is set on newly created files by default. A regular copy will also ignore files and folders that have the system and hidden attribute set.
Quoting Microsoft Knowledgebase: By default, an object inherits permissions from its parent object, either at the time of creation or when it is copied or moved to its parent folder. The only exception to this rule occurs when you move an object to a different folder on the same volume. In this case, the original permissions are retained.
Copying to a share is handled the same as copying to another volume, I think. I'm lazy to look it up.
Last but not least, a copy also changes the owner. When you copy files created with a user account other than the one you're copying with, the owner changes to the one doing the copy with.
All this can lead to problems when you sync system folders or your profile folders, reinstall your pc and think you can simply copy the files back to their new locations. Later versions of Windows can handle this situation more gracefully than XP did, but you'd still get a few annoying popups and chances are that orphaned permissions remain on those files and folders. With system or program folders, you might even run into a situation that some programs won't work properly.
Other things a file copy will never include are system areas of disks and volumes. Notably, partition tables, Master Boot Record and a special system partition Vista and later versions create.
Now above I explained what happens when you do the copy from the command line or with Windows Explorer. A good sync tool will have options to change this default behavior. It can copy files and deal with attributes, owners and permissions. Most can deal with changed files and some can even keep a retention for changed and deleted files in a designated folder. It will have options to include system and/or hidden files and will set and reset the archive bit. So, for copying a bunch of
user files to another drive or share, a sync tool may suffice or even offer features which are preferred for certain situations over backup programs. Strictly speaking, its still not a backup but a copy
. System files, OS folders and Program File folders should never be synced with a file sync program.
Generally, setting up a folder sync is more complex because you need to think about ownership of files, permissions and attributes and configure the sync job to do the right thing. Last but not least, file sync tools can never recover an Operating System, recover (part of) the registry or do a full system recovery.
A good backup program is capable of a lot more than simply copying a few files. It can run on schedules, do full, incremental or differential backups, compress, verify, deal with attributes and permissions and can include the system partition, partition tables and master boot record. Some can even include some form of parity to protect against data corruption. Most backup programs offer features to restore to different hardware or resize destination partitions. They can 'image' complete drives and volumes with or without empty space (can be important). A backup program can often also be used to backup single files and folders. But more importantly, backup programs are typically more reliable and are easier to use than file sync programs are.
So backups and file syncs are different things and both have their purpose and should be used for the situation fitting their purpose. One does not replace the other. There is overlap, but there are also distinct differences that separate the two.
What I've deliberately not touched but is vital to how you backup your stuff are encrypted files and volumes (Windows file encryption/pgp/gpg/truecrypt and of course, bitlocker). When using any of these, they can completely mess up how you need to backup and sync/copy files.
Last but not least, I messed up splitting your message into quotes and when trying to correct it I only messed it up more. Then I started to run out of time so I rushed to complete it. Just ask again if I missed something or if its not clear.
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Topic: Drobo- Gimmick or real world storage and backup? (Read 4491 times)