Quite the opposite. Use drives from as many different manufacturers as you can, especially when buying them at the same time. You want to avoid similar lifecycles and similar potential fabrication defects as much as possible, because those things increase the likelihood that they will fall close to each other - particularly with the stress of rebuilding the first one that failed.
To the best of my knowledge, this "drives from the same batch fail at around the same time" folk wisdom has never been demonstrated in statistical studies.
But, I mean, mixing drive models is certainly not going to do any harm.
If everything went fine during production you're probably right. But there have definitely been batches of hard disks with production flaws which caused all drives from that batch to fail in a similar way.
I know it's only what I've experienced but I've been on a 2 weeks of hell from emc drives failing at the same time because dell didn't change up serials. Had 20 raid drives all start failing within a few days of each other and all were consecutive serials.
If I had a dollar for every time rebuilding a RAID array after one failed drive caused a second drive failure in the array in less than 24 hours.... I'd probably buy groceries for a week.
I don't know if you're talking about the sample of cases you've personally witnessed, or the population of all NASes in the world. If the former, that sounds significant. If the latter, it sounds like it's probably not something to worry about.
You can use different manufacturers, just make sure they are the SAME size and speed. You can also get the same ones from the same vendor, just from different online shops to try and offset getting a bad batch.
I always thought you're supposed to buy similar drives so the performance is better for some reason (I guess the same logic as when picking RAM?) but this thread is changing my mind, I guess it doesn't matter after all👀
ram matters because the CPU will use the worse speeds and worse timings of all the sticks, drive reads and rights are buffered so it doesn't really matter
You absolutely can. Of course you'll only be able to use as much capacity as the smallest disk. Sometime ago I was running a secondary mirror with one 8TB disk and 3 disks pretending to be the other 8TB disk. They were 4TB, 3TB and a 1TB - trivial with LVM. Worked without a hitch for a few years till I replaced the three gnomes in a trench coat with another 8TB disk. Obviously that's suboptimal but it works fine under certain loads.
If you haven't looked into it, and if you already have the disks of varying capacity, check out JBOD. You will have to configure a system for backups however as you wont have parity like raid1
I'm aware, but raid 1 is mirroring which is redundancy, a jbod offers no redundancy so a backup would be even more crucial to protecting from data loss. Also i never said raid is a backup.
I usually find the cheapest drives and buy multiple of those, but you should be able to assemble a RAID out of different disks, though you'll be limited to the space of the smallest one in the mirror set.
Also make sure that your RAID systems supports this.