# S.M.A.R.T. info > S.M.A.R.T. drive health monitoring in RouterOS: read drive health, temperature, use and error counters with the /disk smart-info command, and what the reported attributes mean. # S.M.A.R.T. info [*S.M.A.R.T. info CLI Reference*](../../cli-reference/disk/smart-info) S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) is a monitoring system built into modern storage drives. It lets you read diagnostics of the drive: overall health, temperature, use, error counters and, for NVMe drives, the SMART/Health attributes. :::info S.M.A.R.T. information requires the [Storage](../../storage/) package. ::: For any attached storage device that supports S.M.A.R.T., read the diagnostics with the `/disk/smart-info` command: ```ros [admin@MikroTik] > /disk/smart-info nvme1 ``` ```ros [admin@R2DUTRDS22162XG4S4XS2XQ20DISKS] > disk/smart-info nvme1 Columns: OUTPUT OUTPUT smartctl 7.1 2019-12-30 r5022 [aarch64-linux-5.6.3] (local build) Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org === START OF INFORMATION SECTION === Model Number: U.2 SSD 4TG2-P Serial Number: Firmware Version: E21T4C PCI Vendor/Subsystem ID: 0x1bc0 IEEE OUI Identifier: 0x24693e Controller ID: 0 Number of Namespaces: 1 Namespace 1 Size/Capacity: 960,197,124,096 [960 GB] Namespace 1 Formatted LBA Size: 512 Namespace 1 IEEE EUI-64: Firmware Updates (0x02): 1 Slot Optional Admin Commands (0x0017): Security Format Frmw_DL Self_Test Optional NVM Commands (0x0054): DS_Mngmt Sav/Sel_Feat Timestmp Maximum Data Transfer Size: 512 Pages Warning Comp. Temp. Threshold: 100 Celsius Critical Comp. Temp. Threshold: 110 Celsius Supported Power States St Op Max Active Idle RL RT WL WT Ent_Lat Ex_Lat 0 + 20.00W - - 0 0 0 0 5 5 Supported LBA Sizes (NSID 0x1) Id Fmt Data Metadt Rel_Perf 0 + 512 0 0 === START OF SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED SMART/Health Information (NVMe Log 0x02) Critical Warning: 0x00 Temperature: 33 Celsius Available Spare: 100% Available Spare Threshold: 10% Percentage Used: 0% Data Units Read: 5,774,165 [2.95 TB] Data Units Written: 10,770,860 [5.51 TB] Host Read Commands: 75,868,764 Host Write Commands: 61,379,337 Controller Busy Time: 22 Power Cycles: 579 Power On Hours: 4,203 Unsafe Shutdowns: 105 Media and Data Integrity Errors: 0 Error Information Log Entries: 0 Warning Comp. Temperature Time: 0 Critical Comp. Temperature Time: 0 Temperature Sensor 1: 45 Celsius Temperature Sensor 2: 33 Celsius Temperature Sensor 3: 33 Celsius Temperature Sensor 4: 34 Celsius Temperature Sensor 5: 34 Celsius Temperature Sensor 6: 35 Celsius Temperature Sensor 7: 32 Celsius Temperature Sensor 8: 31 Celsius Error Information (NVMe Log 0x01, max 64 entries) No Errors Logged ``` ## Reading the output The important values for drive health: - `SMART overall-health self-assessment test result` - the drive reports whether it considers itself healthy. A drive that reports `FAILED` should be replaced. - `Temperature` - the current temperature of the drive. The warning and critical thresholds are listed in the information section. - `Available Spare` - how much spare capacity the drive still has before it cannot remap bad blocks. When it drops to the `Available Spare Threshold`, the drive is close to the end of its life. - `Percentage Used` - the estimated lifetime use of the drive, based on the manufacturer's rated endurance. At 100% the drive has reached its rated lifespan. - `Unsafe Shutdowns` and `Media and Data Integrity Errors` - how often the drive lost power unexpectedly and how many data errors it detected. Repeated unsafe shutdowns increase the risk of corruption. The output is the same as `smartctl` reports on Linux, so the S.M.A.R.T. documentation of the drive vendor applies. :::note Some USB enclosures cannot pass S.M.A.R.T. information through. If the drive is behind such an enclosure, `/disk/smart-info` reports an error even though the drive itself supports S.M.A.R.T. ::: ## Related - [Disks](./) - formatting, mounting and managing drives.