On Dec 4, 2007 3:09 PM, Konstantin Svist <fry.kun@xxxxxxxxx> wrote: > Tod Merley wrote: > > On Dec 4, 2007 2:03 PM, Konstantin Svist <fry.kun@xxxxxxxxx> wrote: > > > >> Here's the situation: > >> > >> I have some large mysql db files on my main partition. For some strange > >> reason, some of these files are very slow to be read off the disk: > >> ~3MB/s (I'm SCPing them to another machine). File size doesn't seem to > >> be relevant (other files of approximately same size are being > >> transferred at ~20MB/s), and the speed is not the same throughout the file. > >> > >> My first thought was that the file got very fragmented (I'm fairly sure > >> that the partition was filled up to [almost] 100% at some point). > >> Usually, that can be remedied by copying the file to another location on > >> the same partition.. or rather, that's what would fix fragmented files > >> on NTFS. When I tried that, the read speed of the new file was better by > >> a small amount (up to ~5MB/s) - although that could be because the file > >> was still in the memory cache. > >> > >> I also thought that HD might be nearing the end of its useful lifetime > >> (and has to re-read the sectors, causing the horrible slowdown), but I > >> didn't notice any alerts from SMART (including the output of smartctl > >> -a, anyway) > >> > >> The partition is ~60-70% full, type ext3 with noatime enabled. > >> Speed tests were performed by "scp myfile localhost:/dev/null" > >> > >> > >> > >> ----SNIP > > > > Hi Konstantin Svist! > > > > If I understand the data: > > > > Lots of seek errors - lots of ECC recoveries - running very warm (117 > > degrees Farenheit). Check for cooling issues. Low level format if > > possible. > > > > Sounds kind of like the little guy has worked very hard for you the > > last year and a half! Yes, maybe time to change him out. > > > > Just some thoughts! > > > > Tod > > > > > > Thanks, Tod! > > Just now I checked the value of "195 Hardware_ECC_Recovered" - it seems > to be increasing by a large amount every second. However, the same thing > is happening on most of my HDs (I see that number increase by ~15-20K/s > on the machine with the slow file, and ~45K/s on some 1-month-old SATA > drives (those might have a different load, however). > Is this normal? (these are all HD-intensive servers, BTW, mostly DB > accesses) > > > I also remember hearing on this list that it's not certain how to read > some SMART values... look for thread "Fedora May Be Killing Your > Laptop's Hard Drive?". The attribute in question was "193 > Load_Cycle_Count" but maybe the same thing applies to the other "raw data"? > > > > -- > > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list > Hi again Konstantin Svist! I am no expert, simply an interested party. I did find this study, however: http://research.google.com/archive/disk_failures.pdf Good Reading! Tod
