Issues with SMART attributes of SSD

[Giova84]

Haiku hrev51346 gcc2h

Five days ago I installed an SSD on my computer: a Samsung 850 EVO - 250 GB. I made two 125 GB partitions (well, since the disk shows 232 GB, these partition have a size of 116 GB): on the first one there is Windows 7 on NTFS, and on the second partition there is Haiku on BeFS (filesystem blocks of this partition are set to 4096 bytes).

On Windows 7 I also installed "Samsung Magician" utility and also CrystalDiskInfo, to check the S.M.A.R.T status of the drive. I discovered these issues when I reboot (in particular cases) or I shutdown Haiku: there are two bad SMART attributes which increase.

These SMART attributes are the following [1]:

ID # 235 - Power Recovery Count (EB - POR Recovery Count): A count of the number of sudden power off cases. If there is a sudden power off, the firmware must recover all of the mapping and user data during the next power on. This is a count of the number of times this has happened.

This one increase every time that I shutdown Haiku. I can say it for sure, since after that I shutdown Windows 7, it doesn't increase.

The second SMART attribute is

ID # 199 - C7 - CRC Error Count: The number of Cycle Redundancy Check (CRC) errors. If there is a problem between the host and the DRAM or NAND flash, the CRC engine will tally the error and store it in this attribute.

This one increase when I do a forced reboot from Haiku, eg after that I trigger a KDL from which I cannot exit cleanly (eg with the es command). Also here, I can say it for sure, since when I reboot Windows 7, this value doesn't increase. After some researching on Google, I also read that this SMART status, sometimes, could be caused by a faulty SATA cable: I have also changed the SATA cable, and however I verirified that occurs only in the described case.

I have to say that when I cleanly reboot Haiku, these SMART attributes doesn't increase: they occurs only on shutdown and on forced reboot due to some KDLs (a KDL which often occurs, eg, when I run the fstrim command from Terminal). The SSD is new and so the Haiku partition, so I see no way of an Hardware cause. From Windows 7 is always fine: it doesn't increase these values.

If a run checkfs, however, no errors are reported. I had similar issues in past, on my old computer with a mechanical hard disk, cfr ticket:6847 but on an SSD, obviously, I can't hear any hard disk's heads noise :-)

[1] ​http://web.archive.org/web/20140311153329/http://www.samsung.com/global/business/semiconductor/minisite/SSD/us/html/about/whitepaper07.html

[axeld]

It does indeed sound like the same issue as #6847.

[Giova84]

Yes, sound similar. However, differently from ticket:6847#comment:11 where I said:

if I shutdown Haiku from the default shutdown command present in the Deskbar menu, at the next boot i lose some files (also corrupted), instead all is fine if I shutdown Haiku using "shutdown -q"

Now, on another new computer with my newly fresh SSD, I never get filesystem corruptions and I don't lose files after shutdown (regular or quick).