Disk drives suck less than they did a couple of years ago. Which is nice

Cloud backup bod Backblaze: Failure rates fell for high-cap spinners

Just 139 out of 10,000 12TB Seagate drives fail a year, and Western Digital's HGST brand has an even better rate of 51 in 10,000, according to cloud backup service provider Backblaze, which has 104,778 drives spinning in its data centre.

It's not an exhaustive study; the firm listed just four brands in its estate, with models ranging from older ones with 3TB of capacity to newer 12TB drives and some 14TB drives from Toshiba. However, it does provide some data points for the curious.

It has 31,146 Seagate 12TB disks and 1,278 HGST 12TB spinners. The backup firm claimed the best ever drives it purchased were 45 Toshiba 5TB units, none of which had failed. But of course the sample size of 45 is too small for a valid annualised failure rate (AFR).

Backblaze said: "None of the 45 Toshiba 5TB drives (model MD04ABA500V) have failed since Q2 2016. While the drive count is small, that's still a pretty good run."

The next best is a Seagate 10TB drive with a 0.33 per cent AFR from a population of 1,210 drives. That means 33 out of a batch of 10,000 would fail each year.

MFG	Model	Drive size	Drive count	Drive days	Failures	Annualised failure rate
HGST	HDS5C4040ALE	4TB	50	23,069	1	1.58%
HGST	HMS5C4040ALE640	4TB	4,704	1,801,804	24	0.49%
HGST	HMS5C4040BLE640	4TB	14,550	5,435,466	54	0.36%
Seagate	ST4000DM000	4TB	23,236	9,961,154	581	2.13%
Toshiba	MD04ABA400V	4TB	145	52,850	1	0.69%
Toshiba	MD04ABA500V	5TB	45	16,335	0	0%
Seagate	ST4000DM00	6TB	1,524	632,412	17	0.98%
WDC	WD60EFRX	6TB	383	152,703	9	2.15%
HGST	HUH728080ALE600	8TB	1,045	378,238	7	0.68%
Seagate	ST8000DM002	8TB	9,874	3,589,822	92	0.94%
Seagate	ST8000NM0055	8TB	14,383	5,224,893	126	0.88%
Seagate	ST10000NM0086	10TB	1,210	442,260	4	0.33%
HGST	HUH721212ALN604	12TB	1,278	71,079	1	0.51%
Seagate	ST12000NM0007	12TB	31,146	7,768,206	296	1.39%
Toshiba	MG07ACA14TA	14TB	1,205	108,536	9	3.03%
		Totals	104,778	35,658,927	1,222	(average) 1.25%

Backblaze has 1,205 Toshiba MG07 14TB drives, first announced in December 2017. Their AFR calculated by Backblaze is 3.03 per cent; 303 drives out of 10,000 would fail.

It sounds bad compared to the Seagate and HGST 12TB drives, but HDDs tend to fail early in their lifecycle. Those that don't carry on running well for a long time. Backblaze said: "The initial AFR is just over 3 per cent, which is similar to the other new models and we would expect the AFR to drop over time as the drives settle in."

It added: "The AFR for 2018 for all drive models was just 1.25 per cent, well below the rates from previous years." In 2016 the average AFR was 1.95 per cent, and it was 1.77 per cent in 2017. ®