Hi, I'm switching over from FreeNAS to Ubuntu Server 12.04 for my NAS box and am converting my ZFS pools to mdadm RAIDs and am having some serious issues reading/streaming files over SMB.
Server is AMD E-350 APU with 8GB DDR3 RAM.
I have two 1.5TB hard drives of different makes in a RAID0 configuration, and then shared over the network using samba.
Individually, one drive would copy over SMB to my desktop at 100 MB/s, the other at around 70 MB/s. (the first is a Seagate ST1500DL003 5900 RPM drive and the second is a WD Green WD15EADS with a few more hours under its belt.)
When striped together, I get a MAX of 10 MB/s under the same network conditions. When ssh'd into the server browsing the drive simply doesn't feel snappy either. Totally different than my old ZFS stripe which worked fine.
Here's what I used to create the RAID and create the file system:
I understand some of my file system options may be risky, but I tried it yesterday with the defaults (didn't specify chunk, stride, stripe-width; no journal tuning) and got the same result.Code:parted -a optimal /dev/sdb mkpart primary 1MiB 100% set 1 raid on quit parted -a optimal /dev/sdc mkpart primary 1MiB 100% set 1 raid on quit mdadm --create --verbose /dev/md0 --level=stripe --chunk=32 --raid-devices=2 /dev/sdb1 /dev/sdb2 mkfs.ext4 -b 4096 -E stride=8,stripe-width=16 /dev/md0 tune2fs -O has_journal -o journal_data_writeback /dev/md0 tune2fs -O dir_index /dev/md0 e2fsck -D /dev/md0 mdadm --detail --scan >> /etc/mdadm/mdadm.conf mount /dev/md0 /mnt/storage -o noatime,nodiratime,data=writeback,stripe=16,barrier=0,errors=remount-ro
I also know that I will lose the stripe if I lose one drive, I understand that, I have nightly backups running.
Here's some more information:
Code:#cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid0 sdb1[0] sdc1[1] 2930274240 blocks super 1.2 32k chunks unused devices: <none>Code:#mdadm -D /dev/md0 /dev/md0: Version : 1.2 Creation Time : Sat Aug 10 16:20:23 2013 Raid Level : raid0 Array Size : 2930274240 (2794.53 GiB 3000.60 GB) Raid Devices : 2 Total Devices : 2 Persistence : Superblock is persistent Update Time : Sat Aug 10 16:20:23 2013 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 Chunk Size : 32K Name : oldtown:0 (local to host oldtown) UUID : e50ae570:427d0db7:475bc4cc:8f86f703 Events : 0 Number Major Minor RaidDevice State 0 8 17 0 active sync /dev/sdb1 1 8 33 1 active sync /dev/sdc1Code:#hdparm -tT /dev/md0 /dev/md0: Timing cached reads: 2122 MB in 2.00 seconds = 1060.41 MB/sec Timing buffered disk reads: 302 MB in 4.59 seconds = 65.80 MB/secCode:#dd if=/dev/zero of=testfile bs=1M count=5000 5000+0 records in 5000+0 records out 5242880000 bytes (5.2 GB) copied, 65.2134 s, 80.4 MB/s #dd if=testfile of=/dev/zero bs=1M 5+0 records in 5+0 records out 5242880000 bytes (5.2 GB) copied, 4.0535 s, 1.3 GB/s #dd if=/dev/zero of=testfile bs=1000M count=5 5+0 records in 5+0 records out 5242880000 bytes (5.2 GB) copied, 65.4636 s, 80.1 MB/s #dd if=testfile of=/dev/zero bs=1000M 5+0 records in 5+0 records out 5242880000 bytes (5.2 GB) copied, 5.69963 s, 920 MB/sExcerpt from smb.confCode:#time cp testfile testfile2 real 2m42.178s user 0m0.100s sys 0m19.525
Code:[storage] comment= path=/mnt/storage guest ok=yes browseable=yes create mask=0744 directory mask=0755 read only=no follow symlinks=yes wide links=no
Thanks in advance for your help!
Also for what it's worth, the 3TB drive is running UFS right now and when samba shared transfers at a speedy 100 MB/s.
Adv Reply
Why did you move from ZFS, a VERY reliable filesystem, to a RAID0? I'm sure you know the downside of losing a disk in RAID0, so I'll move on, but I'd at least consider adding some parity (mdadm RAID5/6, ZFS, or 
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