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> The reported SSD lifetime is reported to be around 94%, with over 170+ TB of data written Glad for the guy, but here are a bit different view on the same QVO

> The reported SSD lifetime is reported to be around 94%, with over 170+ TB of data written Glad for the guy, but here are a bit different view on the same QVO series: Device Model: Samsung SSD 870 QVO 1TB User Capacity: 1,000,204,886,016 bytes [1.00 TB] == /dev/sda 9 Power_On_Hours 0x0032 091 091 000 Old_age Always - 40779 177 Wear_Leveling_Count 0x0013 059 059 000 Pre-fail Always - 406 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 354606366027 == /dev/sdb 9 Power_On_Hours 0x0032 091 091 000 Old_age Always - 40779 177 Wear_Leveling_Count 0x0013 060 060 000 Pre-fail Always - 402 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 354366033251 == /dev/sdc 9 Power_On_Hours 0x0032 091 091 000 Old_age Always - 40779 177 Wear_Leveling_Count 0x0013 059 059 000 Pre-fail Always - 409 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 352861545042 == /dev/sdd 9 Power_On_Hours 0x0032 091 091 000 Old_age Always - 40778 177 Wear_Leveling_Count 0x0013 060 060 000 Pre-fail Always - 403 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 354937764042 == /dev/sde 9 Power_On_Hours 0x0032 091 091 000 Old_age Always - 40779 177 Wear_Leveling_Count 0x0013 059 059 000 Pre-fail Always - 408 241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 353743891717 NB you need to look at the first decimal number in 177 Wear_Leveling_Count to get the 'remaining endurance percent' value, ie 59 and 60 here While overall it's not that bad, losing only 40% after 4.5 years - it means what in another 3-4 years it would be down to 20% if the usage pattern wouldn't change and the system wouldn't hit the write amplification. Sure, someone had that "brilliant" idea ~5 years ago to use a desktop grade QLC flash as a ZFS storage for PVE...

yrro 1y ago
Have a look at the SSD Statistics page of the device statistics log (-l smart). This has one "Percentage Used Endurance Indicator" value, which is 5 for three of these disks, and 6 for one of them. So based on that, the drives still have ~95% of their useful life left. As I understand it, the values in the device statistics log have standardized meanings that apply to any drive model, whereas any details about SMART attributes (as in the meaning of a particular attribute or any interpretation of its value apart from comparing the current value with the threshold) are not. So absent a data sheet for this particular drive documenting how to interpret attribute 177, I would not feel confident interpreting the normalized value as a percentage; all you can say is that the current value is > the threshold so the drive is healthy.
- justsomehnguy 1y ago
  == /dev/sda 177 Wear_Leveling_Count PO--C- 059 059 000 - 406 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator == /dev/sdb 177 Wear_Leveling_Count PO--C- 060 060 000 - 402 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator == /dev/sdc 177 Wear_Leveling_Count PO--C- 059 059 000 - 409 0x07 0x008 1 43 N-- Percentage Used Endurance Indicator == /dev/sdd 177 Wear_Leveling_Count PO--C- 060 060 000 - 403 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator == /dev/sde 177 Wear_Leveling_Count PO--C- 059 059 000 - 408 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator Yeah, it's better for sure. I did 'smartctl -x | grep Percent', it's easier. I said about 177 because it's the same numbers what PVE gives in the webui and I didn't found the obvious 'wearout/lifeleft' I'm accustomed to see in the SMART attributes.
wtallis 1y ago
Building an array of five 1TB QLC drives seems like a really odd decision, like somebody started with the constraint that they must use exactly five SSDs and then tried to optimize for cost. The 4TB models obviously will hold up better under 170+ TB of writes than the 1TB drives will, and it wouldn't be surprising to see less write amplification on the larger drives.
- deleted 1y ago
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yrro 1y ago

Have a look at the SSD Statistics page of the device statistics log (-l smart). This has one "Percentage Used Endurance Indicator" value, which is 5 for three of these disks, and 6 for one of them. So based on that, the drives still have ~95% of their useful life left. As I understand it, the values in the device statistics log have standardized meanings that apply to any drive model, whereas any details about SMART attributes (as in the meaning of a particular attribute or any interpretation of its value apart from comparing the current value with the threshold) are not. So absent a data sheet for this particular drive documenting how to interpret attribute 177, I would not feel confident interpreting the normalized value as a percentage; all you can say is that the current value is > the threshold so the drive is healthy.

justsomehnguy 1y ago
== /dev/sda 177 Wear_Leveling_Count PO--C- 059 059 000 - 406 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator == /dev/sdb 177 Wear_Leveling_Count PO--C- 060 060 000 - 402 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator == /dev/sdc 177 Wear_Leveling_Count PO--C- 059 059 000 - 409 0x07 0x008 1 43 N-- Percentage Used Endurance Indicator == /dev/sdd 177 Wear_Leveling_Count PO--C- 060 060 000 - 403 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator == /dev/sde 177 Wear_Leveling_Count PO--C- 059 059 000 - 408 0x07 0x008 1 42 N-- Percentage Used Endurance Indicator Yeah, it's better for sure. I did 'smartctl -x | grep Percent', it's easier. I said about 177 because it's the same numbers what PVE gives in the webui and I didn't found the obvious 'wearout/lifeleft' I'm accustomed to see in the SMART attributes.

wtallis 1y ago

Building an array of five 1TB QLC drives seems like a really odd decision, like somebody started with the constraint that they must use exactly five SSDs and then tried to optimize for cost. The 4TB models obviously will hold up better under 170+ TB of writes than the 1TB drives will, and it wouldn't be surprising to see less write amplification on the larger drives.

deleted 1y ago
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