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Hard Drive Troubles

After my recent hard drive failure, I purchased a pair of new hard disk drives to serve as a replacement. I also purchased an external hard disk enclosure that holds two drives. Unfortunately, things have not been going well.

Backup System

My current backup system is simple. I store data on multiple, offline hard disk drives. The majority of the drives are only rarely powered on, to update a backup or to read some data from a backup. Drives are paired, and I use different brands for each drive in a pair since drives that are manufactured together often fail at around the same time. The drives are encrypted, and I synchronize the data using rsync.

As I mentioned in a status report blog entry, my desktop computer is quite dated. It is very noisy, and I tend to avoid using it unless I really need to. Unfortunately, that computer is currently the only way that I can synchronize pairs of backup drives. Connecting drives to it using SATA is also the only way for me to read from or write to hard disk drives at a decent speed, as my laptop is old and only has USB 2 for connecting to external drives.

One of the reasons that I purchased an external hard disk enclosure that holds two drives is that I would like a way to perform small synchronizations from my laptop. This would make it much easier for me to maintain better backups of my most critical data.

Podcasts Drive

The failed podcast drive was not managed well. While other drives are in storage and are only taken out when needed, I have been treating the podcast drive differently. I used to manage podcasts on my computer drive and synchronize with the backup drives weekly, but I changed this practice when I started to work from home in 2020. I started to manage the podcasts directly on the drive, and the drive was almost always kept out of storage due to frequent usage.

My plan for the external enclosure was to keep the primary podcasts drive in the enclosure. I could then continue to use it frequently, but it would no longer be outside of a case. The drive would still be almost always powered off, and I would only remove the drive when using the enclosure to synchronize other drives.

New Hardware

I purchased two 4TB 3.5 inch hard disk drives: a Western Digital Blue and a Seagate BarraCuda.

There is an unexpected problem with the Seagate drive: it is thinner than a standard 3.5 inch drive! Seagate drives that I purchased before were normal, so this is the first one I have seen that is thin. Looking at the Amazon page, I do not know if there is any indication that it is not the standard size. It is a problem because it is very difficult to get into and out of the SATA bays on my desktop as well as the new enclosure. Perhaps I will use it as a fixed drive in the desktop, as it is not a good backup drive due to this problem.

It was very difficult to select an enclosure. These days we have a large selection of products available, but many of them are low quality. Amazon reviews are better than having no such information at all, but it is often quite difficult to determine what can be trusted.

I initially hoped to get an enclosure that could hold four or five drives with separate power switches for each drive. Such an enclosure would allow me to keep my most frequently used drives easily accessible without having them powered on all the time! Unfortunately, a comment indicated that such enclosures can be dangerous because they tend to power down drives while they are still spinning.

I ended up selecting an ORICO Hard Disk Case that holds two drives. I will not make use of the hardware RAID functionality, but it also works without RAID. (The enclosure and manual lists PM, RAID 0, RAID 1, and SPAN/JBOD modes. I figured that “PM” is what I want by process of elimination, but it took me a long time to figure out that “PM” stands for “port mapping.” From what I understand, it is a SATA feature that allows more than one drive to be indexed on the same bus.)

Speed Problems

Accessing either drive using the new enclosure is way too slow! After noticing the issue, I tested the drives without encryption by running the following simple script using the time command:

#!/usr/bin/env bash

dd if=/dev/zero of=test.data bs=1MB count=1000 status=progress
sync

My dated desktop has a SATA 2 interface, which has a bandwidth throughput of 300 MB/s. This can be confirmed on the command line:

$ sudo smartctl -i /dev/sdb | grep ^SATA
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)

This result, for the Western Digital drive, indicates that the drive itself supports SATA 3.1 (with a 6.0 Gb/s rate) but is currently connected at 3.0 Gb/s because the system uses SATA 2. These are spinning disks, however, and I get the following transfer rates in practice:

Drive Rate (MB/s)
Western Digital 140.8
Seagate 135.1

On my laptop, I connect to external drives using USB 2, which has a bandwidth throughput of 60 MB/s. I have been using a SATA to USB device and measured the following transfer rates:

Drive Rate (MB/s)
Western Digital 39.8
Seagate 38.9

When using the enclosure, I measured the following transfer rates:

Drive Rate (MB/s)
Western Digital 2.9
Seagate 19.9

The Seagate transfer rate was initially about 8.5 MB/s but transferred at a much improved rate for this test, though still about half of the expected rate. I have no idea what caused the change. (When I first measured the drives, I used units based on powers of two. I then remembered that units based on powers of ten are used for storage, so I redid all of the tests. There were no changes on the software side, and no reboots.)

I tested with single drives in the enclosure as well as with both drives in the enclosure simultaneously, mounting one at a time as well as mounting both, and the transfer rates are consistent.

I also tried using the enclosure with my desktop, also via USB 2. I measured the following transfer rates:

Drive Rate (MB/s)
Western Digital 33.5
Seagate 34.2

While not as fast as my previous USB 2 solution, it is comparable… Moving the USB cable to my laptop, without powering down the enclosure, I measured the following transfer rates:

Drive Rate (MB/s)
Western Digital 2.9
Seagate 8.7

The Western Digital transfer rate is the same as before, and the Seagate transfer rate is back to what I was initially seeing! Switching to a different USB port on my laptop, I measured the following transfer rates:

Drive Rate (MB/s)
Western Digital 2.9
Seagate 21.0

My Adobe laptop is newer and has USB 3, so I booted Tails from a USB stick to test on it. I measured the following transfer rates:

Drive Rate (MB/s)
Western Digital 54.6
Seagate 144.9

Investigating dmesg and lsusb output, I confirmed that USB 3.0 is being used, with the UAS driver. The Seagate transfer rate is higher than on the desktop, but the Western Digital rate is low.

Plans

The enclosure is too slow to use with the laptop that I planned on using it with. I do not know if it is because the device that I received is a dud or if it is a poor quality product in general. I will inquire about returning it.

If I am unable to return the enclosure, I may see if anybody would like to buy it from me. It has decent transfer rates with USB 3, and perhaps it works better with macOS or Windows.

If nobody wants to buy it, I may keep it in storage for a while. I need to get a new laptop before long, and perhaps I can make use of it when I use a laptop with USB 3. Alternatively, I may get rid of it at Hard Off.

Author

Travis Cardwell

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