[mythtv-users] 3TB...poof

[Stephen Worthington]

On Thu, 21 Mar 2019 12:27:20 +0800, you wrote:

>
>
>> On 20 Mar 2019, at 11:19 pm, mythtv-users-request at mythtv.org wrote:
>> 
>>> As the cost of flash drops it looks more and more attractive. You *can* get 4T samsung SSDs.
>> 
>> Except that when you run the figures for a MythTV recording drive,
>> even a 4 TByte SSD will get worn out pretty rapidly.  That is for the
>> level of recording I do though, which is pretty heavy.  When huge SSDs
>> get down in price enough that you can afford to replace them every 4-5
>> years, then they will be the right choice for MythTV.  But we are not
>> there yet.
>
>
>Actually Stephen that is not true. Shock horror amazement (me not you):
>
>[sandypit] /home/jam [1002]% !459
>sudo /usr/sbin/smartctl -A /dev/sda
>[sudo] password for root:
>smartctl 6.6 2017-11-05 r4594 [x86_64-linux-4.12.14-lp150.12.45-default] (SUSE RPM)
>Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org
>
>=== START OF READ SMART DATA SECTION ===
>SMART Attributes Data Structure revision number: 1
>Vendor Specific SMART Attributes with Thresholds:
>ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
>  5 Reallocated_Sector_Ct   0x0033   100   100   010    Pre-fail  Always       -       0
>  9 Power_On_Hours          0x0032   099   099   000    Old_age   Always       -       1956
> 12 Power_Cycle_Count       0x0032   099   099   000    Old_age   Always       -       25
>177 Wear_Leveling_Count     0x0013   099   099   000    Pre-fail  Always       -       3
>179 Used_Rsvd_Blk_Cnt_Tot   0x0013   100   100   010    Pre-fail  Always       -       0
>181 Program_Fail_Cnt_Total  0x0032   100   100   010    Old_age   Always       -       0
>182 Erase_Fail_Count_Total  0x0032   100   100   010    Old_age   Always       -       0
>183 Runtime_Bad_Block       0x0013   100   100   010    Pre-fail  Always       -       0
>187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
>190 Airflow_Temperature_Cel 0x0032   062   048   000    Old_age   Always       -       38
>195 Hardware_ECC_Recovered  0x001a   200   200   000    Old_age   Always       -       0
>199 UDMA_CRC_Error_Count    0x003e   100   100   000    Old_age   Always       -       0
>235 Unknown_Attribute       0x0012   099   099   000    Old_age   Always       -       12
>241 Total_LBAs_Written      0x0032   099   099   000    Old_age   Always       -       3425086849
>
>Recording 1/2 doz shows / day on a samsung 1T disk with a total write life of 600T
>
>Based on 3 months usage 
>that’s 1.7T yielding a lifetime of 86 years.
>
>4T cheapest 4 bit mlc is 2x that.
>
>James

I record a bit more than that:

Number of shows:
    5252
Number of episodes:
    60734
First recording:
    Sunday November 29th, 2009
Last recording:
    Thursday March 21st, 2019
Total Running Time:
    9 years 3 months 20 days 16 hrs 43 mins
Total Recorded:
    6 years 12 days 11 hrs 30 mins
Percent of time spent recording:
    64%

A quick estimate of my recording seems to come out at just above 30
Gbytes per day, based on how much my free space has gone down since I
installed a 12 Tbyte drive to replace an old 3 Tbyte one.

But even then, it would be viable to use an SSD for recording now, as
that works out to 54 years of endurance at my rate of recording.  But
not for storage - I would still need to move recordings off on to hard
drives:

Recording space
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdb3       3.7T  2.9T  818G  78% /mnt/rec1
/dev/sdd2        11T   11T  818G  93% /mnt/rec2
/dev/sda5       2.7T  1.9T  816G  70% /mnt/rec3
/dev/sdo1       3.7T  2.9T  817G  79% /mnt/rec4
/dev/sdc1       2.8T  2.0T  819G  71% /mnt/rec5
/dev/sdn1       3.7T  2.9T  819G  79% /mnt/rec6
/dev/sde1       5.5T  4.7T  818G  86% /mnt/rec7
total            33T   27T  5.6T  83% -

I think 33 Tbytes of SSD would still be a little too expensive.