August 22, 20169 yr As we know, there is one weak point in UnRaid which don't support checksum feature. Anyone can suggest ways of doing similar thing?
August 22, 20169 yr Author Thanks johnnie. But have you experienced data loss when the server rebooted suddenly (in latest version of unRaid 6.1.9)? I have tried below steps: 1. create/copy document in same user share folder 2. confirm the change (i.e. open again the document to confirm the content) 3. reboot the machine immediatetly 4. the change will be lost.... how come? What should I test to ensure the change applied.... is to stop the array first before machine restart...
August 22, 20169 yr Community Expert 3. reboot the machine immediatetly Are rebooting using the webGUI?
August 22, 20169 yr Author No, I tested the scenario when power suddenly off. But what I expected result is the change should be kept (write directly to the disk because I only have one disk and no parity and cache disk)
August 22, 20169 yr Community Expert No, I tested the scenario when power suddenly off. But what I expected result is the change should be kept (write directly to the disk because I only have one disk and no parity and cache disk) All disk writes are potentially cached in RAM so that there can be a short delay (typically a second or two) before changes get written to disk. This can be avoided by doing a controlled shutdown so that the data gets flushed from RAM. Simply pressing the power button is always liable to lose the last few writes.
August 22, 20169 yr Community Expert No, I tested the scenario when power suddenly off. But what I expected result is the change should be kept (write directly to the disk because I only have one disk and no parity and cache disk) Like Itimpi pointed out, writes are cached to RAM, I believe by default for up to 30 seconds, if you're worried about unexpected power loss get a UPS.
August 22, 20169 yr Author Thanks itimpi. But I can find the document is updated successfully when I reopen it before reboot. I also try to remove / copy file and then reboot immediately and these will hit the data loss again. What should I expect same result as that in WIN OS, no data loss once the file is saved/deleted/copied
August 22, 20169 yr Community Expert Thanks itimpi. But I can find the document is updated successfully when I reopen it before reboot. Because you're open it from RAM.
August 22, 20169 yr Community Expert What should I expect same result as that in WIN OS, no data loss once the file is saved/deleted/copied You can get the same result even in Windows if it is set to do some RAM caching. On any OS it is a performance trade-off as to whether to allow write-caching or not. Windows typically seems to sacrifice some performance by doing more frequent flushing than is the norm on Linux.
August 23, 20169 yr Author ok, could we have configure the default value to reduce time; or ways of ensuring data transfer successfully when some important data copied?
August 23, 20169 yr ways of ensuring data transfer successfully when some important data copied? if you're worried about unexpected power loss get a UPS.Expecting a server to operate properly when the power is removed suddenly without shutting down properly is not a realistic option.
Archived
This topic is now archived and is closed to further replies.