Mix 7200 & 5400 RPM HDDs???

[vlad1966]

I'm currently running FreeNAS 9.2 and will soon move to 9.3. I have (2) 4TB & (2) 3TB HDDs each running in RAID 1, all 7200rpm drives.

I'll be needing to add 2 more 4TB HDDs (growing movie collection), but I'm considering 5400rpm drives instead of 7200rpm for reduced heat and noise. Then I'd like to put all (4) 4TB HDDs into a RAID 5 array.

My question is, will I have any RAID issues if 2 of the drives are 5400rpm & 2 are 7200rpm?
Also running Plex Media Server on FreeNAS. Would the mixed drives speeds have any effect?

TIA!

 

[pirateghost]

What raid 1 and raid 5 are you talking about?

 

[SweetAndLow]

ZFS is perfectly happy to mix drive speeds.

 

[omcn7]

9.10 FreeNAS I keep updated, daily snapshots, scrubs once a week. 32GB error correcting RAM etc etc. :)
I have two zpools:
RaidZ mirror 2x 4TB WD red 5400 rpm NAS drives
RaidZ1 3x 2TB WD red 5400 rpm NAS drives

I have just purchased a Seagate st4000dm000 desktop 4TB 5900 rpm drive to add to my raidz mirror and make it a RaidZ1.

They both have 64MB cache, I do hope the difference in speed will not mess with the zpool as noted by SweetAndLow :)

We will see. I hope the seagate will just step down a notch and not create a great deal of buffer in ram when writing to the other slower drives. I have ram to spare most of the time but still.. I like to keep things nice and neat.

 

[Robert Trevellyan]

raidz mirror

Just a heads-up - "RAIDZ mirror" is not a thing. "RAIDZ" and "mirror" are two different types of vdev layout. RAIDZ is short for RAIDZ1, as distinct from RAIDZ2 or RAIDZ3. In general RAIZx means "parity information is distributed across all the disks in the vdev", while mirror means "each disk in the vdev has an identical copy of the data".

 

[Ericloewe]

In general RAIZx means "parity information is distributed across all the disks in the vdev"

"Data, including parity, is distributed across all the disks in the vdev" would be more accurate. Don't want people to start thinking weird things about RAIDZ - they do plenty of that on their own.