take a look at this before buying Seagate
@ChuckPa said:
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In a Pool, you are correct, you can lose a drive and its data without recovery. RAID provides this recovery by way of parity.
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That is simply not true. Just like in a raid with parity a pool with duplication protects you from the loss of a drive.
The biggest advantage of parity in a raid over duplication in a pool is that it generally takes less actual space but that advantage is less in the current world because storage is so cheap. The advantage of duplication in a pool is that there is no downtime when you loose a disk. Things just keep cranking along and no restore is required. Of course you have to replace the failed drive but that is true no matter what system you use.
I am not really trying to argue against using raid I am just trying to knock down some mistaken beliefs that a LOT of people hold. It is even possible that current raids do not have a down time for restore after a failure but all the ones that I have ever dealt with did.
@Elijah_Baley said:
I am not really trying to argue against using raid I am just trying to knock down some mistaken beliefs that a LOT of people hold. It is even possible that current raids do not have a down time for restore after a failure but all the ones that I have ever dealt with did.
We use RAID at work. Our NX4 is definitely old tech, but we run multiple RAID 5 pools with parity and none of them suffer any downtime when a drive fails. Pop in a new drive to replace the failed drive and everyone still has access to files while the drive is rebuilt.
@Elijah_Baley said:
@ChuckPa said:
…
In a Pool, you are correct, you can lose a drive and its data without recovery. RAID provides this recovery by way of parity.
…That is simply not true. Just like in a raid with parity a pool with duplication protects you from the loss of a drive.
The biggest advantage of parity in a raid over duplication in a pool is that it generally takes less actual space but that advantage is less in the current world because storage is so cheap. The advantage of duplication in a pool is that there is no downtime when you loose a disk. Things just keep cranking along and no restore is required. Of course you have to replace the failed drive but that is true no matter what system you use.
I am not really trying to argue against using raid I am just trying to knock down some mistaken beliefs that a LOT of people hold. It is even possible that current raids do not have a down time for restore after a failure but all the ones that I have ever dealt with did.
To augment, RAID 5, 6, and those with distributed parity (a.k.a. support operation in degraded mode) DO support operation while the raid set is rebuilding. There is no ‘down time’. This is one of the key selling points. With Synology specifically, I can hot-swap a failed drive and the system will keep right on going without reboot
@OttoKerner said:
Just the backup has to be done separately from these drives.
You are doing backups, don’t you?And no, RAID is not a backup.
@kegobeer-plex said:
We use RAID at work. Our NX4 is definitely old tech, but we run multiple RAID 5 pools with parity and none of them suffer any downtime when a drive fails. Pop in a new drive to replace the failed drive and everyone still has access to files while the drive is rebuilt.
And so everyone gets this concept and why backups are still as important -
RAID means you WILL have a drive failure, it will happen MORE often than a single drive, and that’s EXPECTED. There are all sorts of RAID Disk Failure Calculators available on the interwebs…
It also means that you buy another hard drive, slap it in and move on, while the person who insisted one single large drive in a server for both OS and client data will run fine tries to restore from tape with people breathing down his neck…
@m.hutchinson said:
RAID means you WILL have a drive failure, it will happen MORE often than a single drive, and that’s EXPECTED. There are all sorts of RAID Disk Failure Calculators available on the interwebs…It also means that you buy another hard drive, slap it in and move on, while the person who insisted one single large drive in a server for both OS and client data will run fine tries to restore from tape with people breathing down his neck…
As always, RAID is not a way to back up data. Tape backups and offsite storage (cloud/tape/etc) are the only way to ensure data is available in the event of drive failure.
