Hi,

 

I quite often have an issue where my speed drops significantly during the middle of copying a file to my unraid server.

 

I use a cache SSD drive - and it is enabled for the drives I am using.  I also check after and see that the files are on the cache drive so it is copying to the ssd cache (and it is not full).  (all computers hard wired / cate5e, no wireless).

 

speeds typically start out at 112MB/sec and sometimes stay steady at that rate for the whole file - other times it drops to ~21MB/sec (see attached screen shot).

 

I also run the SSD trim plugin and have it set to run daily.

 

any ideas on what it could be, or how to troubleshoot this?

 

thanks

 

 

Hi,

 

I quite often have an issue where my speed drops significantly during the middle of copying a file to my unraid server.

 

I use a cache SSD drive - and it is enabled for the drives I am using.  I also check after and see that the files are on the cache drive so it is copying to the ssd cache (and it is not full).  (all computers hard wired / cate5e, no wireless).

 

speeds typically start out at 112MB/sec and sometimes stay steady at that rate for the whole file - other times it drops to ~21MB/sec (see attached screen shot).

 

I also run the SSD trim plugin and have it set to run daily.

 

any ideas on what it could be, or how to troubleshoot this?

 

thanks

Are you sure its winding up on the cache?  Those figures sound like unRaid is caching it in RAM and then when that's full dumping it to the array disks.

Hi

 

Yes I just went and checked again.  Browsed to cache drive and they are still there (mover has not run yet).

 

I'm using 6.2.4.

 

thanks

 

is it a cheap ssd? those often start off fast on transfers and then die off down to spinning disk speed or worse. (first hand experience with a couple)

It is a Samsung 840 Evo - seems to be a reasonable SSD from what I can tell.

 

 

Post your diagnostics zip (Tools -> Diagnostics) so that we can see if there's a problem.

 

is it a cheap ssd? those often start off fast on transfers and then die off down to spinning disk speed or worse. (first hand experience with a couple)

 

Would you care to name them so that others are forewarned? I don't know which SSDs are good and which are not so good.

Post your diagnostics zip (Tools -> Diagnostics) so that we can see if there's a problem.

 

Hi- see attached for diagnostics

 

thanks

tower-diagnostics-20170128-1652.zip

is it a cheap ssd? those often start off fast on transfers and then die off down to spinning disk speed or worse. (first hand experience with a couple)

 

Would you care to name them so that others are forewarned? I don't know which SSDs are good and which are not so good.

Reviews on Anandtech are a good place to start...

is it a cheap ssd? those often start off fast on transfers and then die off down to spinning disk speed or worse. (first hand experience with a couple)

 

Would you care to name them so that others are forewarned? I don't know which SSDs are good and which are not so good.

Reviews on Anandtech are a good place to start...

+1

 

Also avoid any planar tlc ssd.

 

As for the OP's problem log looks good, trim is working, still looks like an SSD issue, make sure you're using the latest firmware, this model had a speed problem, although it affected mostly read speed.

is it a cheap ssd? those often start off fast on transfers and then die off down to spinning disk speed or worse. (first hand experience with a couple)

 

Would you care to name them so that others are forewarned? I don't know which SSDs are good and which are not so good.

Reviews on Anandtech are a good place to start...

+1

 

Also avoid any planar tlc ssd.

 

As for the OP's problem log looks good, trim is working, still looks like an SSD issue, make sure you're using the latest firmware, this model had a speed problem, although it affected mostly read speed.

 

Hi - never tried updating firmware on a drive in the unraid server.  Do I have to pull the SSD and put it into my windows PC to update the firmware?  or is there a way to do from linux?

thanks

It should be easier using Windows and the Samsung Magician software, better to backup your cache before doing it just in case.

is it a cheap ssd? those often start off fast on transfers and then die off down to spinning disk speed or worse. (first hand experience with a couple)

 

Would you care to name them so that others are forewarned? I don't know which SSDs are good and which are not so good.

 

cheap SSD drives i've used personally in unRaid and other platforms that had horrible sustained write speeds (meaning initial writes  at sub 200MB/s and dropping to 80MB or less):

 

Kingston SSD Now series

PNY CS1311

Patriot Blast/Blaze

 

read speeds are usually "ok" but none perform like my samsung 840 or 850 drives, but they are also 1/2 the price or less...

Thanks. I don't have any of those. I have mostly SanDisk ones, a couple of SK Hynix and some Toshiba mSATA cards. They're fast enough for me and seem reliable, though the mSATA cards run quite hot.