Seagate Personal Cloud Retest

[DNet]

I don't get it... The drives' transfer rates are already much faster than the local area networks, even 1000BT, due to overhead in TCP/IP, SMB, NTFS, etc. and moreso the file systems.

Sequential writes when used as DAS were falling to around 30MB/s or even less - and staying there. A good 1GbE NAS should sustain ~80-110MB/s.

Random reads/writes are already often much slower than a 1000BT network, so the drive becomes the bottleneck - that's normal. But this was sequential writes - without even having a network involved! So I didn't get it either. Was there something else you didn't get?


I don't know if you're like me, but I often tend to forget how these non-sequential accesses are important too. I have an older 17" MacBook Pro with an original SATA 1.5Gbps interface. I tried both an "older" Samsung 830 and a new Samsung 850 Pro SSD in it. The newer disk seemed a little faster. "How could that be?," I first thought. "The bottleneck is the 150-185MB/s SATA interface." But over the last few years, Samsung has improved their random and small file performance - especially in the 850 Pro. These small/random accesses are still slow enough that even the original SATA interface is faster - so you can still get some benefit.

 

[sfx2000]

Well, I'll have plenty of time to prove you right - or wrong. It's just that I'm not doing my big NTFS transfer just yet. But if the new drives work faster I may be able to do it sooner rather than later ... - when a transfer stretches into day(s) it really holds me up!

Right or wrong - these are incredibly dense drives, and a pretty decent value - might not be optimal for near-line storage, but for archival, they are probably one of the better solutions out there...

 

[DNet]

The plot thickens ...

And I really don't buy the excuse of File System support - sorry sir, that dog just don't hunt...

It turns out it absolutely does matter which file system you're using. So your dog assessment skills were way off this time.

However, I just discovered that the 4TB, non-SMR Backup Plus drives exhibit identical behavior! I hope to know more tomorrow.

 

[sfx2000]

Good discussion - fairly technical - on SMR here

https://www.usenix.org/conference/fast15/technical-sessions/presentation/aghayev

Sounds like these aren't too bad for cold-storage/backup/archival - read performance isn't too bad, but random write performance in a NAS or Desktop (or RAID array) - current implementations, esp. Drive Managed SMR, I can't recommend them in a near-line/online storage solution.

But for backup - they're excellent, and so far, at least for Drive Managed implementations, they're pretty much a drop-in.

HGST - they've recently launched a high density SMR drive, the 10TB Ha10, but their solution is host-managed, so it does require drivers in the OS, which might limit what platforms are supported.

 

[sfx2000]

The plot thickens ...

It turns out it absolutely does matter which file system you're using. So your dog assessment skills were way off this time.

However, I just discovered that the 4TB, non-SMR Backup Plus drives exhibit identical behavior! I hope to know more tomorrow.

after taking some time to dig and investigate further - I agree with you that there is some filesystem dependencies perhaps, but it's more about how the host OS is writing data to the drives and scheduling those writes with the host adapter...

Where SMR could be useful perhaps - is putting a very large SMR hard disk, and pairing it with a fast/low latency SSD in a logical volume structure, similar to what Apple has done with their Fusion Drives, or Samsung RAPID/Intel Rapid Storage Tech - interesting as a tiered storage medium, and abstracting HW from the OS - one is still doing FS calls, but to the logical, not physical, volume...

Would make recovery a pain in the you know what...

 

[stlbud]

In the review of the Seagate Personal Cloud, the author stated, "We usually ding products that rely on UPnP for remote access, so the PC gets a demerit for this." but offers no analysis of the service used to share files through the Internet.

Has any analysis been done to check the security of using Seagate (a company whose status changes frequently and dramatically) as a connection to the PC? Is Seagate merely providing a dynamic dns service? What ports are being used? Is there a way to use the PC without using the Seagate service?

 

[pommepatate4]

I recently bought this Personal Cloud and I'm happy with the speed. It is the 5TB single bay model. The only concern I have for now is the fact that it doesn't spin down after the 20 minutes, it doesn't spin down at all. It is running on firmware 4.2.8.8 so reading this thread I thought it would properly spindown since the update from 4.1.5.13 to 4.1.5.15 for this test solved the issue in the SNB article. What shoud I do for it to spin down? Should I return it and get a 4TB instead?

 

[Jeffrey Goldman]

Sequential writes when used as DAS were falling to around 30MB/s or even less - and staying there. A good 1GbE NAS should sustain ~80-110MB/s.

Random reads/writes are already often much slower than a 1000BT network, so the drive becomes the bottleneck - that's normal. But this was sequential writes - without even having a network involved! So I didn't get it either. Was there something else you didn't get?


I don't know if you're like me, but I often tend to forget how these non-sequential accesses are important too. I have an older 17" MacBook Pro with an original SATA 1.5Gbps interface. I tried both an "older" Samsung 830 and a new Samsung 850 Pro SSD in it. The newer disk seemed a little faster. "How could that be?," I first thought. "The bottleneck is the 150-185MB/s SATA interface." But over the last few years, Samsung has improved their random and small file performance - especially in the 850 Pro. These small/random accesses are still slow enough that even the original SATA interface is faster - so you can still get some benefit.

It seems to me a use case requiring over 100 GB of files is pretty rare and won't affect most people using these as media servers or even B/U for attached laptops or PCs. While a full backup of most of my attached PCs is still under 100 GB (programs and data) the data only portion is at best a few GBs. Also, as a media server it only needs to transfer around 100 Mbps to stream even a full rip Blu Ray and few people due that as full rip Blu Rays would only allow 35-40 movies/Terabyte. Maybe I'm missing something here but it still seems like you are a very unique use case compared to most people (even the ones that use this site and forum.