From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrei Banu Subject: Re: Incredibly poor performance of mdraid-1 with 2 SSD Samsung 840 PRO Date: Thu, 25 Apr 2013 00:40:56 +0300 Message-ID: <51785168.8050200@redhost.ro> References: <5171CBF9.9020701@redhost.ro> <51732E2B.6090607@hardwarefreak.com> <5174501F.80509@redhost.ro> <51747382.1010105@hardwarefreak.com> <5a749bb56c88b6d6b8a806694b163bda@redhost.ro> <5175F71A.8030805@hardwarefreak.com> <51765FD7.8090309@redhost.ro> <51775078.3000500@hardwarefreak.com> <51779720.6040109@redhost.ro> <5177A1E7.8030701@websitemanagers.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5177A1E7.8030701@websitemanagers.com.au> Sender: linux-raid-owner@vger.kernel.org Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, 1. free -m root [~]# free -m total used free shared buffers cached Mem: 15921 15542 379 0 1063 11870 -/+ buffers/cache: 2608 13313 Swap: 2046 100 1946 2. Yes, you understood correctly regarding the raid array (all 3 of them are raid 1): root@gts6 [~]# cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb2[1] sda2[0] 204736 blocks super 1.0 [2/2] [UU] md2 : active raid1 sdb3[1] sda3[0] 404750144 blocks super 1.0 [2/2] [UU] md1 : active raid1 sdb1[1] sda1[0] 2096064 blocks super 1.1 [2/2] [UU] unused devices: md0 is boot. md1 is swap. md2 is / 3. df root@gts6 [~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/md2 380G 246G 116G 68% / tmpfs 7.8G 0 7.8G 0% /dev/shm /dev/md0 194M 47M 137M 26% /boot /usr/tmpDSK 3.6G 1.2G 2.2G 36% /tmp 4. pvs root [~]# pvs -a PV VG Fmt Attr PSize PFree /dev/loop0 --- 0 0 /dev/md0 --- 0 0 /dev/md1 --- 0 0 /dev/ram0 --- 0 0 /dev/ram1 --- 0 0 /dev/ram10 --- 0 0 /dev/ram11 --- 0 0 /dev/ram12 --- 0 0 /dev/ram13 --- 0 0 /dev/ram14 --- 0 0 /dev/ram15 --- 0 0 /dev/ram2 --- 0 0 /dev/ram3 --- 0 0 /dev/ram4 --- 0 0 /dev/ram5 --- 0 0 /dev/ram6 --- 0 0 /dev/ram7 --- 0 0 /dev/ram8 --- 0 0 /dev/ram9 --- 0 0 /dev/root --- 0 0 5. lvs (No volume groups). Thanks! On 24/04/2013 12:12 PM, Adam Goryachev wrote: > On 24/04/13 18:26, Andrei Banu wrote: >> Hello, >> >> I am sorry for the irrelevant feedback. Where I misunderstood your >> request, I filled in the blanks (poorly). >> >> 1. SWAP >> root [~]# blkid | grep cef1d19d-2578-43db-9ffc-b6b70e227bfa >> /dev/md1: UUID="cef1d19d-2578-43db-9ffc-b6b70e227bfa" TYPE="swap" >> >> So yes, swap is on md1. This *md1 has a size of 2GB*. Isn't this way >> too low for a system with 16GB of memory? >> > Provide the output of "free", if there is RAM available, then it isn't > too small (that is my personal opinion, but at least it won't affect > performance/operations until you are using most of that swap space). > >> 3. root [~]# fdisk -lu /dev/sd* >> > My mistake, I should have said: > fdisk -lu /dev/sd? > > In any case, all of the relevant information was included, so no harm done. >> Disk /dev/sda: 512.1 GB, 512110190592 bytes >> 255 heads, 63 sectors/track, 62260 cylinders, total 1000215216 sectors >> Units = sectors of 1 * 512 = 512 bytes >> Sector size (logical/physical): 512 bytes / 512 bytes >> I/O size (minimum/optimal): 512 bytes / 512 bytes >> Disk identifier: 0x00026d59 >> >> Device Boot Start End Blocks Id System >> /dev/sda1 2048 4196351 2097152 fd Linux raid >> autodetect >> Partition 1 does not end on cylinder boundary. >> /dev/sda2 * 4196352 4605951 204800 fd Linux raid >> autodetect >> Partition 2 does not end on cylinder boundary. >> /dev/sda3 4605952 814106623 404750336 fd Linux raid >> autodetect >> >> Disk /dev/sdb: 512.1 GB, 512110190592 bytes >> 255 heads, 63 sectors/track, 62260 cylinders, total 1000215216 sectors >> Units = sectors of 1 * 512 = 512 bytes >> Sector size (logical/physical): 512 bytes / 512 bytes >> I/O size (minimum/optimal): 512 bytes / 512 bytes >> Disk identifier: 0x0003dede >> >> Device Boot Start End Blocks Id System >> /dev/sdb1 2048 4196351 2097152 fd Linux raid >> autodetect >> Partition 1 does not end on cylinder boundary. >> /dev/sdb2 * 4196352 4605951 204800 fd Linux raid >> autodetect >> Partition 2 does not end on cylinder boundary. >> /dev/sdb3 4605952 814106623 404750336 fd Linux raid >> autodetect >> > I'm assuming from this you have three md RAID1 arrays where sda1/sdb1 > are a pair, sda2/sdb2 are a pair and sda3/sdb3 are a pair? > > Can you describe what is on each of these arrays? > Output of > cat /proc/mdstat > df > pvs > lvs > > Might be helpful.... > > Regards, > Adam >