<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi Dylan,<div class=""><br class=""></div><div class="">It depends on:</div><div class=""><br class=""></div><div class="">* Whether the sector failure rate is increasing, particularly if the increase is marked (that indicates a drive near end of life).</div><div class=""><br class=""></div><div class="">* How critical the data on the drive is. </div><div class=""><br class=""></div><div class="">Generally, once sectors start to fail, all of the memory on the drive will have aged to the point that more and more will fail over time. The drive is certainly still usable for non-critical applications on a desktop machine on data that isn't financial, health related, or otherwise mission critical (meaning changes to the data will either get you sued for millions of dollars or endanger human life).</div><div class=""><br class=""></div><div class="">The expectation is a server SSD, that may be storing financial or critical data, should look like this:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 5 Reallocated_Sector_Ct 0x0032 100 100 000 Old_age Always - 0</span></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 15708</span></div></div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 5 Reallocated_Sector_Ct 0x0032 100 100 000 Old_age Always - 0</span></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 15708</span></div></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">That data is from two mirrored SSDs on Nyx, one of my production servers. Drives have been running for a total of 15,700 hours or two year at 24/7/365</div><div class=""><br class=""></div><div class="">If that number changes from zero, I will require OVH to replace the drive in question, and have a 3AM scheduled outage while the array rebuilds.</div><div class=""><br class=""></div><div class="">And from my 7 year old, 2012 Macbook Pro</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 5 Reallocated_Sector_Ct 0x0033 100 100 000 Pre-fail Always - 0</span></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 9 Power_On_Hours 0x0032 096 096 000 Old_age Always - 18196</span></div></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class="">In spite of </span></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(242, 242, 242); background-color: rgb(0, 0, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">173 Wear_Leveling_Count 0x0032 191 191 100 Old_age Always - 304961552547</span></div></span></div><div class=""><div><br class=""></div><div>If you have a gaming PC, and you keep daily backups of your uni work, you definitely can keep using an SSD once it starts showing wear, although I'd begin to budget for its replacement, and there may be an argument for selling it on Ebay (with a warning about its reallocated sectors, if you are honest).</div><div><br class=""></div><div>If it's as UCC, then... I wouldn't allow it on Ashera, but the rest of the machines are up to Wheel discretion.</div><div><br class=""></div><div>If anyone's life, or livelihood depends on data not being corrupted, please Goddess no. Where the data on the drive is work 100x or more what the drive is worth, you don't want such scenarios.</div><div><br class=""></div><div>Regards,</div><div><br class=""></div><div>Melissa</div><div><br class=""></div><div><br class=""></div><div><blockquote type="cite" class=""><div class="">On 18 Mar 2019, at 4:59 pm, Dylan H <<a href="mailto:dylanh333@ucc.asn.au" class="">dylanh333@ucc.asn.au</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="auto" class="">Hi Melissa,<div dir="auto" class=""><br class=""></div><div dir="auto" class="">Can you please clarify whether it really is an issue to have any reallocated sectors at all on an SSD, even if only very few?</div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">My understanding is that the Raw Value is the actual number of sectors reallocated, and the Value is the normalised value, which should not reach the threshold (lower is worse, so a Value of 98 is better than 20).</div><div dir="auto" class="">Assuming this, I don't imagine a small handful of reallocated sectors is much of an issue, unless the normalised value is getting close to the threshold (0 in this case), as most SSDs come with a sizeable chunk of spare, hidden sectors to swap in, as far as I am aware.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">My main concern is that replacing an SSD that only has a small handful of reallocated sectors but a normalised value of 90+ (for example) would be a bit wasteful, when it still has 90% to go before reaching the vendor-defined threshold.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">Thanks! </div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">Kind regards,</div><div dir="auto" class="">Dylan Hicks [333]</div><br class=""><div class="gmail_extra" dir="auto"><br class=""><div class="gmail_quote">On 18 Mar 2019 3:13 pm, Melissa Star <<a href="mailto:melissa@netexperts.com.au" class="">melissa@netexperts.com.au</a>> wrote:<br type="attribution" class=""><blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class="">Hi Everyone,<div class=""><br class=""></div><div class="">I just realised - if you have smartmontools installed on linux machines, each hard drive or SSD will provide its “Airflow Temperature”, which I can extract via script.</div><div class=""><br class=""></div><div class="">I'm thinking of centralising this for all the servers I run, and collecting the data to chart, having a display at home that gives me live info for all machines under my control.</div><div class=""><br class=""></div><div class="">I could make a similar display for UCC, which could be on the website and/or a monitor in the club room (although this would likely be in the winter holidays due to increasing workload).</div><div class=""><br class=""></div><div class="">Note the <b class="">reallocated sector count </b>for SSDs, once this starts to happen, the drive should be replaced. </div><div class=""><br class=""></div><div class="">For SSDs (and also HDDs) mounted at the front of servers, because they are getting airflow to the sensor sucked in directly from ambient air, and are thermally insulated from the rest of the machine, this will <b class="">be equal to the temperature of the room</b>.</div><div class=""><br class=""></div><div class="">For example, right now, the UCC server room temperature is <b class="">29 degrees, </b>according to 3 of the four installed drives, and <b class="">30 degrees</b> according to the 4th one.</div><div class=""><br class=""></div><div class="">For PCs, the same test will provide the temperature in the case. Some drives also have a count of total hours run outside of their acceptable temperature range and G/shocks or drops, as well as all types of other interesting data.</div><div class=""><br class=""></div><div class="">If there is an interest, I could parse this data, and the page with Ashera-related information could provide it and could also e-mail (and/or SMS) warnings to anyone on the list if the temperature passes a key threshold.</div><div class=""><br class=""></div><div class="">Here is what the data actually looks like (I've highlighted the airflow temperature):</div><div class=""><br class=""></div><div class=""><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">smartctl -d sat -a /dev/pass1</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">smartctl 7.0 2018-12-30 r4883 [FreeBSD 12.0-STABLE amd64] (local build)</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Copyright (C) 2002-18, Bruce Allen, Christian Franke, <a href="http://www.smartmontools.org/" class="">www.smartmontools.org</a></div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 );min-height:16px" class=""><br class=""></div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">=== START OF INFORMATION SECTION ===</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Device Model: Samsung SSD 860 QVO 1TB</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Serial Number: S4CZNG0M138175F</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">LU WWN Device Id: 5 002538 e701b1df5</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Firmware Version: RVQ01B6Q</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">User Capacity: 1,000,204,886,016 bytes [1.00 TB]</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Sector Size: 512 bytes logical/physical</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Rotation Rate: Solid State Device</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Form Factor: 2.5 inches</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Device is: Not in smartctl database [for details use: -P showall]</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">ATA Version is: ACS-4 T13/BSR INCITS 529 revision 5</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">SATA Version is: SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Local Time is: Mon Mar 18 15:03:46 2019 AWST</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">SMART support is: Available - device has SMART capability.</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">SMART support is: Enabled</div></div><div class="">... (cut to prevent this email becoming ridiculous) ...</div><div class=""><br class=""></div><div class=""><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">SMART Attributes Data Structure revision number: 1</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">Vendor Specific SMART Attributes with Thresholds:</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class=""> 5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class=""> 9 Power_On_Hours 0x0032 099 099 000 Old_age Always - 648</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class=""> 12 Power_Cycle_Count 0x0032 099 099 000 Old_age Always - 15</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">177 Wear_Leveling_Count 0x0013 100 100 000 Pre-fail Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">179 Used_Rsvd_Blk_Cnt_Tot 0x0013 100 100 010 Pre-fail Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">181 Program_Fail_Cnt_Total 0x0032 100 100 010 Old_age Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">182 Erase_Fail_Count_Total 0x0032 100 100 010 Old_age Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">183 Runtime_Bad_Block 0x0013 100 100 010 Pre-fail Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo'" class=""><span style="background-color:rgb( 255 , 255 , 2 )" class=""><font color="#fefefe" class="">190 Airflow_Temperature_Cel 0x0032 071 058 000 Old_age Always - 29</font></span></div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">195 Hardware_ECC_Recovered 0x001a 200 200 000 Old_age Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">199 UDMA_CRC_Error_Count 0x003e 100 100 000 Old_age Always - 0</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">235 Unknown_Attribute 0x0012 099 099 000 Old_age Always - 13</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">241 Total_LBAs_Written 0x0032 099 099 000 Old_age Always - 336661820</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 );min-height:16px" class=""><br class=""></div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">SMART Error Log Version: 1</div><div style="margin:0px;font-stretch:normal;font-size:14px;line-height:normal;font-family:'menlo';color:rgb( 242 , 242 , 242 );background-color:rgb( 0 , 0 , 0 )" class="">No Errors Logged</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Regards,</div><div class=""><br class=""></div><div class="">Melissa</div></div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></div></body></html>