I keep reading mixed reports on the Seagate 4TB 2.5" HDDs (specifically the ST4000LM016). I'm trying to figure out if they are SMR or PMR. I also want to know if they are a good fit for a RAID 5 on an LSI controller or within FreeNAS. Anyone have any thoughts?
Thoughts on Seagate 4TB 2.5" HDD
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I am running ~30 of them in various ZFS configurations. 16 of them are running in FreeNAS.
Its not clear if they are PMR or SMR. There are mixed reports and frankly they don't quite act like either. Perhaps some sort of hybrid (we know Seagate uses hybrid PMR/SMR on large 3.5" drives).
They work fine in a ZFS RaidZ/RaidZ2 pool under FreeNAS. Slow - but fine. They read reasonably fast but don't seek worth cr@p. If you want them for backups or a media pool to feed your Kodi/Plex then they are all good - in fact really good. If you want them for active work they might not be the best. If you are serving more than a 3 or 4 user community from FreeNAS then probably not. Probably wouldn't try to use them for VM images.
As for reliability I've had one soft-fail out of 30 in about 8 months, and it failed within about 30 days (infant mortality). This actually makes them among the more reliable spinny disks i've used.
Its not clear if they are PMR or SMR. There are mixed reports and frankly they don't quite act like either. Perhaps some sort of hybrid (we know Seagate uses hybrid PMR/SMR on large 3.5" drives).
They work fine in a ZFS RaidZ/RaidZ2 pool under FreeNAS. Slow - but fine. They read reasonably fast but don't seek worth cr@p. If you want them for backups or a media pool to feed your Kodi/Plex then they are all good - in fact really good. If you want them for active work they might not be the best. If you are serving more than a 3 or 4 user community from FreeNAS then probably not. Probably wouldn't try to use them for VM images.
As for reliability I've had one soft-fail out of 30 in about 8 months, and it failed within about 30 days (infant mortality). This actually makes them among the more reliable spinny disks i've used.
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I have 12 of these in RAID 6 on a LSI 9260. These have been running without issue for about 8 months now. I never did look at the performance but it's been fine for my bulk storage.
I don't think I would recommend them on hardware raid and this wasn't my intended use for these but I didn't have an HBA on hand when I needed the storage so put them on the 9260 and they've been fine so far.
When I have time these will go onto ZFS with more I bought over Christmas.
I don't think I would recommend them on hardware raid and this wasn't my intended use for these but I didn't have an HBA on hand when I needed the storage so put them on the 9260 and they've been fine so far.
When I have time these will go onto ZFS with more I bought over Christmas.
I have the original 4 kicking around in my array after copying 10TB to them in a StorageSpaces arrangement. The performance is atrocious on write after hitting some sort of limit I go from 144MB/s down to 10MB/s. Right now this is taking me 1day to sync 1.5TB of space from a USB 3.0 array to my internal storage spaces array. I did add in 2 of the 5TB seagate disks that run at 7200rpm and they seem to be working a touch better.
The 5TB's were 170$ at amazon and for the extra 50$ were designed to do what I wanted them to do. That extra cash is worth it and I will probably unload these 4TB's after I fill up the 4n1 array I have right now with 5TB disks.
The 5TB's were 170$ at amazon and for the extra 50$ were designed to do what I wanted them to do. That extra cash is worth it and I will probably unload these 4TB's after I fill up the 4n1 array I have right now with 5TB disks.
I'm assuming the 5tb are these: Amazon.com: Seagate Backup Plus 5TB Portable External Hard Drive USB 3.0 (Silver) STDR5000101: Computers & Accessories
review: Seagate Introduces BarraCuda 2.5” HDDs with Up to 5 TB Capacity
Note an interesting point in the review: "All the new BarraCuda 2.5” HDDs feature 128 MB of DRAM cache as well as multi-tier caching (MTC) technology, which is designed to hide peculiarities of SMR. Hard drives featuring shingled recording write new magnetic tracks that overlap part of the previously written tracks. This may slow down the writing process since the architecture requires HDDs to rewrite adjacent tracks after any writing operation. To “conceal” such peculiarities, Seagate does a number of tricks. Firstly, it organizes SMR tracks into bands in a bid to limit the amount of overwriting. Secondly, the MTC technology uses several bands of PMR tracks on the platters, around 1 GB of NAND flash cache as well as DRAM cache. When workloads generate relatively small amount of writes, the HDD writes data to NAND and/or to the PMR tracks at a predictable data rate. Then, during light workloads or idle time, the HDD transfers written data from the caches to SMR tracks, as described by Mark Re (CTO of Seagate) earlier this year."
This probably explains why they suck in write mode after a while.
review: Seagate Introduces BarraCuda 2.5” HDDs with Up to 5 TB Capacity
Note an interesting point in the review: "All the new BarraCuda 2.5” HDDs feature 128 MB of DRAM cache as well as multi-tier caching (MTC) technology, which is designed to hide peculiarities of SMR. Hard drives featuring shingled recording write new magnetic tracks that overlap part of the previously written tracks. This may slow down the writing process since the architecture requires HDDs to rewrite adjacent tracks after any writing operation. To “conceal” such peculiarities, Seagate does a number of tricks. Firstly, it organizes SMR tracks into bands in a bid to limit the amount of overwriting. Secondly, the MTC technology uses several bands of PMR tracks on the platters, around 1 GB of NAND flash cache as well as DRAM cache. When workloads generate relatively small amount of writes, the HDD writes data to NAND and/or to the PMR tracks at a predictable data rate. Then, during light workloads or idle time, the HDD transfers written data from the caches to SMR tracks, as described by Mark Re (CTO of Seagate) earlier this year."
This probably explains why they suck in write mode after a while.
So far these drives have been decent. You seem to crap on Seagate every thread you go in to. Yes the 3TB drives sucked. These are not those drives.Seagate make excellent paper weights