[Samba] Vista performance (uggh)

Tue Oct 30 14:37:46 GMT 2007

On 10/26/2007 8:28 AM, Doug Tucker wrote:
> I didn't see anyone answer this.  We noticed a tremendous slowdown of
> our samba server the minute we put our first Vista client on it due to
> IO.  Turns out that by default, Vista has an indexing feature turned on
> that sits there and loops continually indexing every file it can find.
> So if you have mapped drives, and they have a lot of content...this user
> had about 2gb in their home directory, it just murdered our samba
> server.  I'm no vista expert, but why you don't see a noticeable
> performance hit when it indexes the local drive of the pc, I have no
> idea, but when it was sitting on that mapped drive, it slowed the samba
> server down for everyone.  We turned that feature off on the Vista
> machine, and the problem went away.

This theory would apply if I was seeing lots of disk I/O even while the
vista client wasn't actively transferring files.  That isn't the case.
I only see increased I/O during a file copy from the samba server to the
vista client.

Speaking of vista issues.  You may want to considering disabling
"Offline Files" which also keeps an eye of what files are new/changed on
the fileshare and copies them locally.  This kicks in automatically if
you set any of your special folders (Documents and Pictures is what I
had done) to be on the samba server rather than local).

> 
> 
> 
> On Thu, 2007-10-18 at 09:57 -0500, samba at lists.rupa.com wrote:
>> Issue: Vista reads slowly from a samba server.  This appears to pop up
>> periodically here and elsewhere.
>>
>> My samba.conf file has:
>>
>> [homes]
>>  ...
>>  vfs objects = readahead
>>
>>  As suggested elsewhere.
>>
>> Writes are approximately 17-18MB/s which is acceptable.  Reads are in
>> the 8MB/s range which is appalingly slow.  Using linux smbclient and
>> windows XP clients I can read at 25+MB/s.  I've enabled vfs objects =
>> readahead to get better performance in vista.
>>
>> The biggest difference I notice between vista and other clients is that
>> the %iowait is MUCH higher than with the other clients.  Logs show the
>> readahead module being loaded but I have no idea if it is actually doing
>> anything.
>>
>> [2007/10/18 08:24:48, 2] lib/module.c:do_smb_load_module(64)
>>   Module '/usr/lib/samba/vfs/readahead.so' loaded
>>
>>
>> Server Config:
>>
>> CPU: Amd Athlon 2600+
>> Ram: 1G
>> Disk: software raid5 across 5 250G ide drives each on dedicated channels
>> Kernel: Linux shakti 2.6.22 #1 SMP Wed Oct 17 15:32:01 CDT 2007 i686
>> GNU/Linux
>> Distro: debian etch
>>
>> Network: Gigabit (though cheapo)
>>
>> Any suggestions on where to go from here?
>>
>> iostat 5 output for the physical devices below:
>>
>> Using a new quad core running Vista client on gigabit
>>   - Reads at 8MB/s
>>
>> avg-cpu:  %user   %nice %system %iowait  %steal   %idle
>>            2.81    0.00    9.62   73.95    0.00   13.63
>>
>> Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
>> hda              51.10      3033.27        20.84      15136        104
>> hde              53.91      3028.46        16.03      15112         80
>> hdg              49.90      2993.19        19.24      14936         96
>> hdi              47.49      3036.47         6.41      15152         32
>> hdk              49.30      2993.19        14.43      14936         72
>>
>>
>> Using a midrange Laptop running Windows XP on gigabit
>>   - Reads at 20MB/s
>>
>> avg-cpu:  %user   %nice %system %iowait  %steal   %idle
>>            3.80    0.00   23.80   14.20    0.00   58.20
>>
>> Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
>> hda             199.80      8366.40        25.60      41832        128
>> hde             187.20      8380.80         8.00      41904         40
>> hdg             190.80      8377.60         9.60      41888         48
>> hdi             178.20      8376.00        16.00      41880         80
>> hdk             188.80      8377.60        20.80      41888        104
>>
>>
>> Using same host, smbclient, writing to a firewire drive
>>   - Reads at 26MB/s
>>
>> avg-cpu:  %user   %nice %system %iowait  %steal   %idle
>>            7.58    0.00   38.92   30.74    0.00   22.75
>>
>> Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
>> hda             224.75      8693.01        20.76      43552        104
>> hde             214.37      8713.77        12.77      43656         64
>> hdg             212.97      8657.88        19.16      43376         96
>> hdi             195.61      8629.14        23.95      43232        120
>> hdk             197.01      8688.22        22.36      43528        112
>>
>> Using dd to firewire drive
>>   - Reads at 27MB/s
>>
>> avg-cpu:  %user   %nice %system %iowait  %steal   %idle
>>            6.40    0.00   59.40   34.20    0.00    0.00
>>
>> Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
>> hda             310.80     12844.80        17.60      64224         88
>> hde             317.80     12820.80         9.60      64104         48
>> hdg             308.60     12779.20        14.40      63896         72
>> hdi             294.00     12779.20         9.60      63896         48
>> hdk             294.80     12796.80        19.20      63984         96
>>
> 