[Samba] long delays with file enumeration & listing in large data storage environment

Wed Feb 8 12:48:56 UTC 2023

hide unreadable = yes

I was under the impression this was a very time consuming option in
domains.

Can you try setting this to no and trying again?

On Tue, Feb 7, 2023, 5:09 p.m. CaptainTrips28 via samba <
samba at lists.samba.org> wrote:

> After joining a Samba server to domain using either Winbind or using
> ADBridge (PBIS), enumeration time of listing files from windows file
> explorer for that share is roughly (9) seconds for a folder containing 30k
> files consisting of both large (upto 15GB in size) and small size files (as
> low as KB's). Intitially, without setting logging to "0" and disabling smb
> max server protocol in smb.conf (which is now defaulting to smb3_11),
> listing of these files would take up to 45 seconds. So we have already
> drastically cut down this time with smb.conf option corrections.
>
> As ~9 seconds may seem trivial to enumerate 30k files, this is only in a
> test scenario with randomly generated junk files. In our production
> scenario, we have folders frequently containing upwards of 100k and 250k
> files and requirements for folders that may contain upto potentially 1
> million files of various sizes and filenames consisting of upper and
> lowercase characters. Assuming the average of around 200k files in the prod
> scenario, the enumeration time would be around 1min10secs to list all
> files. This enumeration delay is causing issues with our end users.
>
> Initially, prior to joining the samba server to domain, using just a local
> smb-enabled account, testing access time from windows file explorer to this
> share of 30k files for enumeration was instaneous (a second or less).
> However, in production, windows AD users are accessing the shares which
> have AD owners and groups assigned to the shares folders and permissions
> based on their level of access.
>
> We have tried numerous config options and variations of options
> enabled/disabled, trying local storage mountpoints on the samba server vs.
> remote mountpoints via NFS and SSHFS. We've tried numerous hardware types:
> a physical HPE Gen11 DL380 system acting the samba server, a virtual samba
> server within vsphere, moving hardware around on network appliances to
> reduce hops and improve throughput. Ipv6 has been disabled, all ports are
> open as required, no antivirus scan interference. From the windows side,
> smb client settings have been tested at various options, confirmed netbios
> is disabled, etc. We've also tried limiting the samba server to one DC and
> ignoring all irrelevant domains. No matter the test scenario, once domain
> joined, the absolute lowest enumeration time we can achieve is the (9)
> seconds until file listing is complete and that is pretty universal outcome
> in each of the above mentioned testing scenarios.
>
> - Tried both RHEL 8.4 and 8.6 (FIPS disabled, SELinux permissive and
> firewalld off)
>
> - Samba versions 4.13.3 (rhel 8.4) and 4.15.5 (rhel 8.6) have both been
> tried with identical outcome, all pulled from RH satellite repos)
>
> - We've tried with stigs both applied and unapplied, as well as folder/file
> encryption both on and off (no difference in performance).
>
> - PBIS/ADBridge was tried with both versions 22.2.x and 22.3.x (latest)
>
> - Testing share access from Windows 2019 Server Datacenter (Build 17763).
> Our user VDA sessions would also being accessing the shares from the same.
>
> - Production environment is enterprise scale; hundreds of users/thousands
> of folders/millions of files
>
> - Share enumeration speed is the same if accessing by either mapped drive,
> file explorer // access, or symbolically linking to the share
>
> Any suggestions/recommendations on how to reduce or eliminate enumeration
> and listing times for these shares is certainly appreciated.
>
>
>
>
> -------------------------------
>
> CURRENT SMB.CONF   (I've had to replace the domain/share/host details for
> privacy):
>
> -------------------------------
>
> [global]
>
>         security = ADS
>
>         workgroup = DOMAIN
>
>         realm = DOMAIN
>
>         machine password timeout = 0
>
>         idmap config * : backend = tdb
>
>         idmap config * : range = 3000-7999
>
>         idmap config DOMAIN.COM:backend = ad
>
>         idmap config DOMAIN.COM:schema_mode = rfc2307
>
>         idmap config DOMAIN.COM:range = 1617000000-1617999999
>
>         idmap config DOMAIN.COM:unix_nss_info = yes
>
>         map acl inherit = yes
>
>         store dos attributes = yes
>
>         log level = 0
>
>         dns proxy = yes
>
>         hostname lookups = yes
>
>         kerberos method = system keytab
>
>         log file = /var/log/samba/log.%m
>
>         smb encrypt = yes
>
>         server signing = auto
>
>         client signing = auto
>
>         vfs objects = acl_xattr
>
>         nt acl support = yes
>
>         netbios name = testhost01
>
>
>
>
>
> [OrgName-OrgGroup-OrgSubgroup-TEST]
>
>         path = /mountpoint/Development/OrgName/OrgGroup/OrgSubgroup/TEST
>
>         writable = yes
>
>         browsable= yes
>
>         read only = no
>
>         create mask = 0770
>
>         force create mode = 0770
>
>         directory mask = 0775
>
>         hide unreadable = yes
>
> #        force group = OrgGroupTest at domain.com
>
> #        valid users = +domain.com\"OrgGroupTest"
>
>
> ---------------------------------------------------------------------------
>
> OTHER SMB.CONF OPTIONS TRIED IN VARIATION:
>
> ---------------------------------------------------------------------------
>
> *(not currently applied as these options either made no difference or
> decreased performance/enumeration):
>
>
>
> (global options we've tried various combinations of. We are aware these
> options are not recommended by modern kernel standards, but tried them
> regardless)
>
> #        username map = /etc/samba/user.map
>
> #        server multi channel support = yes
>
> #        aio read size = 16384
>
> #        aio write size = 16384
>
> #        aio max threads = 100
>
> #        allocation roundup size = 1048576
>
> #        interfaces = "10.100.99.103;speed=10000000000,capability=RSS"
>
> #        winbind max domain connections = 10
>
> #        winbind expand groups = 1
>
> #        socket options = SO_RCVBUF=131072 SO_SNDBUF=131072 TCP_NODELAY
>
> #        min receivefile size = 16384
>
> #        use sendfile = true
>
> #        aio read size = 16384
>
> #        aio write size = 16384
>
> #        aio write behind = true
>
>
> (share options we've tried with no performance improvement even when
> testing lowercase files only)
>
> #        case sensitive = true
>
> #        default case = lower
>
> #        preserve case = no
>
> #        short preserve case = no
> --
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