Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
To close the loop on this topic. The below parameters were not set by default and hence they were not showing up in lctl list_param commands. I have to set them first. lctl set_param llite.*.max_read_ahead_mb=256 lctl set_param llite.*.max_read_ahead_per_file_mb=256 Thanks to the Lustre Community for their help to tune Lustre, I was able to tune Lustre on Oracle Cloud Infrastructure to get good performance on Bare metal nodes with 2x25Gbps network. We have open sourced the deployment of Lustre on Oracle Cloud as well as all the performance tuning done at the Infrastructure level as well as Lustre FS level for everyone to benefit from it. https://github.com/oracle-quickstart/oci-lustre Terraform files are in : https://github.com/oracle-quickstart/oci-lustre/tree/master/terraform Tuning scripts are in this folder: https://github.com/oracle-quickstart/oci-lustre/tree/master/scripts As next step - I plan to test deployment of Lustre on 100 Gbps RoCEv2 RDMA network (Mellanox CX5). Thanks, Pinkesh Valdria Oracle Cloud – Principal Solutions Architect https://blogs.oracle.com/cloud-infrastructure/lustre-file-system-performance-on-oracle-cloud-infrastructure https://blogs.oracle.com/author/pinkesh-valdria From: lustre-discuss on behalf of Pinkesh Valdria Date: Friday, December 13, 2019 at 11:14 AM To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I ran the latest command you provided and it does not show the parameter, like you see.I can do screenshare. [opc@lustre-client-1 ~]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/sda339G 2.5G 36G 7% / devtmpfs158G 0 158G 0% /dev tmpfs 158G 0 158G 0% /dev/shm tmpfs 158G 17M 158G 1% /run tmpfs 158G 0 158G 0% /sys/fs/cgroup /dev/sda1 512M 12M 501M 3% /boot/efi 10.0.3.6@tcp1:/lfsbv 50T 89M 48T 1% /mnt/mdt_bv 10.0.3.6@tcp1:/lfsnvme 185T 8.7M 176T 1% /mnt/mdt_nvme tmpfs32G 0 32G 0% /run/user/1000 [opc@lustre-client-1 ~]$ lctl list_param -R llite | grep max_read_ahead [opc@lustre-client-1 ~]$ So I ran this: [opc@lustre-client-1 ~]$ lctl list_param -R llite > llite_parameters.txt There are other parameters under llite. I attached the complete list. From: "Moreno Diego (ID SIS)" Date: Friday, December 13, 2019 at 8:36 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) >From what I can see I think you just ran the wrong command (lctl list_param -R >* ) or it doesn’t work as you expected on 2.12.3. But llite params are sure there on a *mounted* Lustre client. This will give you the parameters you’re looking for and need to modify to have, likely, better read performance: lctl list_param -R llite | grep max_read_ahead From: Pinkesh Valdria Date: Friday, 13 December 2019 at 17:33 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) This is how I installed lustre clients (only showing packages installed steps). cat > /etc/yum.repos.d/lustre.repo << EOF [hpddLustreserver] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/server/ gpgcheck=0 [e2fsprogs] name=CentOS- - Ldiskfs baseurl=https://downloads.whamcloud.com/public/e2fsprogs/latest/el7/ gpgcheck=0 [hpddLustreclient] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/client/ gpgcheck=0 EOF yum install lustre-client -y reboot From: "Moreno Diego (ID SIS)" Date: Friday, December 13, 2019 at 2:55 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) >From what I can see they exist on my 2.12.3 client node: [root@rufus4 ~]# lctl list_param -R llite | grep max_read_ahead llite.reprofs-9f7c3b4a8800.max_read_ahead_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_per_file_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_whole_mb Regards, Diego From: Pinkesh Valdria Date: Wednesday, 11 December 2019 at 17:46 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was not able to find those parameters on my client nodes, OSS or MGS nodes. Here is how I was extracting all parameters .
Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
I ran the latest command you provided and it does not show the parameter, like you see. I can do screenshare. [opc@lustre-client-1 ~]$ df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 39G 2.5G 36G 7% / devtmpfs 158G 0 158G 0% /dev tmpfs 158G 0 158G 0% /dev/shm tmpfs 158G 17M 158G 1% /run tmpfs 158G 0 158G 0% /sys/fs/cgroup /dev/sda1 512M 12M 501M 3% /boot/efi 10.0.3.6@tcp1:/lfsbv 50T 89M 48T 1% /mnt/mdt_bv 10.0.3.6@tcp1:/lfsnvme 185T 8.7M 176T 1% /mnt/mdt_nvme tmpfs 32G 0 32G 0% /run/user/1000 [opc@lustre-client-1 ~]$ lctl list_param -R llite | grep max_read_ahead [opc@lustre-client-1 ~]$ So I ran this: [opc@lustre-client-1 ~]$ lctl list_param -R llite > llite_parameters.txt There are other parameters under llite. I attached the complete list. From: "Moreno Diego (ID SIS)" Date: Friday, December 13, 2019 at 8:36 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) >From what I can see I think you just ran the wrong command (lctl list_param -R >* ) or it doesn’t work as you expected on 2.12.3. But llite params are sure there on a *mounted* Lustre client. This will give you the parameters you’re looking for and need to modify to have, likely, better read performance: lctl list_param -R llite | grep max_read_ahead From: Pinkesh Valdria Date: Friday, 13 December 2019 at 17:33 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) This is how I installed lustre clients (only showing packages installed steps). cat > /etc/yum.repos.d/lustre.repo << EOF [hpddLustreserver] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/server/ gpgcheck=0 [e2fsprogs] name=CentOS- - Ldiskfs baseurl=https://downloads.whamcloud.com/public/e2fsprogs/latest/el7/ gpgcheck=0 [hpddLustreclient] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/client/ gpgcheck=0 EOF yum install lustre-client -y reboot From: "Moreno Diego (ID SIS)" Date: Friday, December 13, 2019 at 2:55 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) >From what I can see they exist on my 2.12.3 client node: [root@rufus4 ~]# lctl list_param -R llite | grep max_read_ahead llite.reprofs-9f7c3b4a8800.max_read_ahead_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_per_file_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_whole_mb Regards, Diego From: Pinkesh Valdria Date: Wednesday, 11 December 2019 at 17:46 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was not able to find those parameters on my client nodes, OSS or MGS nodes. Here is how I was extracting all parameters . mkdir -p lctl_list_param_R/ cd lctl_list_param_R/ lctl list_param -R * > lctl_list_param_R [opc@lustre-client-1 lctl_list_param_R]$ less lctl_list_param_R | grep ahead llite.lfsbv-98231c3bc000.statahead_agl llite.lfsbv-98231c3bc000.statahead_max llite.lfsbv-98231c3bc000.statahead_running_max llite.lfsnvme-98232c30e000.statahead_agl llite.lfsnvme-98232c30e000.statahead_max llite.lfsnvme-98232c30e000.statahead_running_max [opc@lustre-client-1 lctl_list_param_R]$ I also tried these commands: Not working: On client nodes lctl get_param llite.lfsbv-*.max_read_ahead_mb error: get_param: param_path 'llite/lfsbv-*/max_read_ahead_mb': No such file or directory [opc@lustre-client-1 lctl_list_param_R]$ Works On client nodes lctl get_param llite.*.statahead_agl llite.lfsbv-98231c3bc000.statahead_agl=1 llite.lfsnvme-98232c30e000.statahead_agl=1 [opc@lustre-client-1 lctl_list_param_R]$ From: "Moreno Diego (ID SIS)" Date: Tuesday, December 10, 2019 at 2:06 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) With that kind of degradation performance on read I would immediately think on llite’s max_read_ahead parameters on the client. Specifically these 2: max_read_ahead_mb: total amount of MB allocated for read ahead, usually quite low for bandwidth benchmarking purposes and when there’re several files per client max_read_ahead_per_file_mb: the defa
Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
From what I can see I think you just ran the wrong command (lctl list_param -R * ) or it doesn’t work as you expected on 2.12.3. But llite params are sure there on a *mounted* Lustre client. This will give you the parameters you’re looking for and need to modify to have, likely, better read performance: lctl list_param -R llite | grep max_read_ahead From: Pinkesh Valdria Date: Friday, 13 December 2019 at 17:33 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) This is how I installed lustre clients (only showing packages installed steps). cat > /etc/yum.repos.d/lustre.repo << EOF [hpddLustreserver] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/server/ gpgcheck=0 [e2fsprogs] name=CentOS- - Ldiskfs baseurl=https://downloads.whamcloud.com/public/e2fsprogs/latest/el7/ gpgcheck=0 [hpddLustreclient] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/client/ gpgcheck=0 EOF yum install lustre-client -y reboot From: "Moreno Diego (ID SIS)" Date: Friday, December 13, 2019 at 2:55 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) From what I can see they exist on my 2.12.3 client node: [root@rufus4 ~]# lctl list_param -R llite | grep max_read_ahead llite.reprofs-9f7c3b4a8800.max_read_ahead_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_per_file_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_whole_mb Regards, Diego From: Pinkesh Valdria Date: Wednesday, 11 December 2019 at 17:46 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was not able to find those parameters on my client nodes, OSS or MGS nodes. Here is how I was extracting all parameters . mkdir -p lctl_list_param_R/ cd lctl_list_param_R/ lctl list_param -R * > lctl_list_param_R [opc@lustre-client-1 lctl_list_param_R]$ less lctl_list_param_R | grep ahead llite.lfsbv-98231c3bc000.statahead_agl llite.lfsbv-98231c3bc000.statahead_max llite.lfsbv-98231c3bc000.statahead_running_max llite.lfsnvme-98232c30e000.statahead_agl llite.lfsnvme-98232c30e000.statahead_max llite.lfsnvme-98232c30e000.statahead_running_max [opc@lustre-client-1 lctl_list_param_R]$ I also tried these commands: Not working: On client nodes lctl get_param llite.lfsbv-*.max_read_ahead_mb error: get_param: param_path 'llite/lfsbv-*/max_read_ahead_mb': No such file or directory [opc@lustre-client-1 lctl_list_param_R]$ Works On client nodes lctl get_param llite.*.statahead_agl llite.lfsbv-98231c3bc000.statahead_agl=1 llite.lfsnvme-98232c30e000.statahead_agl=1 [opc@lustre-client-1 lctl_list_param_R]$ From: "Moreno Diego (ID SIS)" Date: Tuesday, December 10, 2019 at 2:06 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) With that kind of degradation performance on read I would immediately think on llite’s max_read_ahead parameters on the client. Specifically these 2: max_read_ahead_mb: total amount of MB allocated for read ahead, usually quite low for bandwidth benchmarking purposes and when there’re several files per client max_read_ahead_per_file_mb: the default is quite low for 16MB RPCs (only a few RPCs per file) You probably need to check the effect increasing both of them. Regards, Diego From: lustre-discuss on behalf of Pinkesh Valdria Date: Tuesday, 10 December 2019 at 09:40 To: "lustre-discuss@lists.lustre.org" Subject: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was expecting better or same read performance with Large Bulk IO (16MB RPC), but I see degradation in performance. Do I need to tune any other parameter to benefit from Large Bulk IO? Appreciate if I can get any pointers to troubleshoot further. Throughput before - Read: 2563 MB/s - Write: 2585 MB/s Throughput after - Read: 1527 MB/s. (down by ~1025) - Write: 2859 MB/s Changes I did are: On oss - lctl set_param obdfilter.lfsbv-*.brw_size=16 On clients - unmounted and remounted - lctl set_param osc.lfsbv-OST*.max_pages_per_rpc=4096 (got auto-updated after re-mount) - lctl set_param osc.*.max_rpcs_in_flight=64 (Had to manually increase this to 64, since after re-mount, it was auto-set to 8, but read/write performance was poor) - lctl set_param osc.*.max_dirty_mb=2040. (setting the value to 2048 was failing with : Numerical result out of range error. Previously it was set to 2000 when I got good perfo
Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
This is how I installed lustre clients (only showing packages installed steps). cat > /etc/yum.repos.d/lustre.repo << EOF [hpddLustreserver] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/server/ gpgcheck=0 [e2fsprogs] name=CentOS- - Ldiskfs baseurl=https://downloads.whamcloud.com/public/e2fsprogs/latest/el7/ gpgcheck=0 [hpddLustreclient] name=CentOS- - Lustre baseurl=https://downloads.whamcloud.com/public/lustre/latest-release/el7/client/ gpgcheck=0 EOF yum install lustre-client -y reboot From: "Moreno Diego (ID SIS)" Date: Friday, December 13, 2019 at 2:55 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) >From what I can see they exist on my 2.12.3 client node: [root@rufus4 ~]# lctl list_param -R llite | grep max_read_ahead llite.reprofs-9f7c3b4a8800.max_read_ahead_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_per_file_mb llite.reprofs-9f7c3b4a8800.max_read_ahead_whole_mb Regards, Diego From: Pinkesh Valdria Date: Wednesday, 11 December 2019 at 17:46 To: "Moreno Diego (ID SIS)" , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was not able to find those parameters on my client nodes, OSS or MGS nodes. Here is how I was extracting all parameters . mkdir -p lctl_list_param_R/ cd lctl_list_param_R/ lctl list_param -R * > lctl_list_param_R [opc@lustre-client-1 lctl_list_param_R]$ less lctl_list_param_R | grep ahead llite.lfsbv-98231c3bc000.statahead_agl llite.lfsbv-98231c3bc000.statahead_max llite.lfsbv-98231c3bc000.statahead_running_max llite.lfsnvme-98232c30e000.statahead_agl llite.lfsnvme-98232c30e000.statahead_max llite.lfsnvme-98232c30e000.statahead_running_max [opc@lustre-client-1 lctl_list_param_R]$ I also tried these commands: Not working: On client nodes lctl get_param llite.lfsbv-*.max_read_ahead_mb error: get_param: param_path 'llite/lfsbv-*/max_read_ahead_mb': No such file or directory [opc@lustre-client-1 lctl_list_param_R]$ Works On client nodes lctl get_param llite.*.statahead_agl llite.lfsbv-98231c3bc000.statahead_agl=1 llite.lfsnvme-98232c30e000.statahead_agl=1 [opc@lustre-client-1 lctl_list_param_R]$ From: "Moreno Diego (ID SIS)" Date: Tuesday, December 10, 2019 at 2:06 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) With that kind of degradation performance on read I would immediately think on llite’s max_read_ahead parameters on the client. Specifically these 2: max_read_ahead_mb: total amount of MB allocated for read ahead, usually quite low for bandwidth benchmarking purposes and when there’re several files per client max_read_ahead_per_file_mb: the default is quite low for 16MB RPCs (only a few RPCs per file) You probably need to check the effect increasing both of them. Regards, Diego From: lustre-discuss on behalf of Pinkesh Valdria Date: Tuesday, 10 December 2019 at 09:40 To: "lustre-discuss@lists.lustre.org" Subject: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was expecting better or same read performance with Large Bulk IO (16MB RPC), but I see degradation in performance. Do I need to tune any other parameter to benefit from Large Bulk IO? Appreciate if I can get any pointers to troubleshoot further. Throughput before - Read: 2563 MB/s - Write: 2585 MB/s Throughput after - Read: 1527 MB/s. (down by ~1025) - Write: 2859 MB/s Changes I did are: On oss - lctl set_param obdfilter.lfsbv-*.brw_size=16 On clients - unmounted and remounted - lctl set_param osc.lfsbv-OST*.max_pages_per_rpc=4096 (got auto-updated after re-mount) - lctl set_param osc.*.max_rpcs_in_flight=64 (Had to manually increase this to 64, since after re-mount, it was auto-set to 8, but read/write performance was poor) - lctl set_param osc.*.max_dirty_mb=2040. (setting the value to 2048 was failing with : Numerical result out of range error. Previously it was set to 2000 when I got good performance. My other settings: - lnetctl net add --net tcp1 --if $interface –peer-timeout 180 –peer-credits 128 –credits 1024 - echo "options ksocklnd nscheds=10 sock_timeout=100 credits=2560 peer_credits=63 enable_irq_affinity=0" > /etc/modprobe.d/ksocklnd.conf - lfs setstripe -c 1 -S 1M /mnt/mdt_bv/test1 ___ lustre-discuss mailing list lustre-discuss@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
I was not able to find those parameters on my client nodes, OSS or MGS nodes. Here is how I was extracting all parameters . mkdir -p lctl_list_param_R/ cd lctl_list_param_R/ lctl list_param -R * > lctl_list_param_R [opc@lustre-client-1 lctl_list_param_R]$ less lctl_list_param_R | grep ahead llite.lfsbv-98231c3bc000.statahead_agl llite.lfsbv-98231c3bc000.statahead_max llite.lfsbv-98231c3bc000.statahead_running_max llite.lfsnvme-98232c30e000.statahead_agl llite.lfsnvme-98232c30e000.statahead_max llite.lfsnvme-98232c30e000.statahead_running_max [opc@lustre-client-1 lctl_list_param_R]$ I also tried these commands: Not working: On client nodes lctl get_param llite.lfsbv-*.max_read_ahead_mb error: get_param: param_path 'llite/lfsbv-*/max_read_ahead_mb': No such file or directory [opc@lustre-client-1 lctl_list_param_R]$ Works On client nodes lctl get_param llite.*.statahead_agl llite.lfsbv-98231c3bc000.statahead_agl=1 llite.lfsnvme-98232c30e000.statahead_agl=1 [opc@lustre-client-1 lctl_list_param_R]$ From: "Moreno Diego (ID SIS)" Date: Tuesday, December 10, 2019 at 2:06 AM To: Pinkesh Valdria , "lustre-discuss@lists.lustre.org" Subject: Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) With that kind of degradation performance on read I would immediately think on llite’s max_read_ahead parameters on the client. Specifically these 2: max_read_ahead_mb: total amount of MB allocated for read ahead, usually quite low for bandwidth benchmarking purposes and when there’re several files per client max_read_ahead_per_file_mb: the default is quite low for 16MB RPCs (only a few RPCs per file) You probably need to check the effect increasing both of them. Regards, Diego From: lustre-discuss on behalf of Pinkesh Valdria Date: Tuesday, 10 December 2019 at 09:40 To: "lustre-discuss@lists.lustre.org" Subject: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was expecting better or same read performance with Large Bulk IO (16MB RPC), but I see degradation in performance. Do I need to tune any other parameter to benefit from Large Bulk IO? Appreciate if I can get any pointers to troubleshoot further. Throughput before - Read: 2563 MB/s - Write: 2585 MB/s Throughput after - Read: 1527 MB/s. (down by ~1025) - Write: 2859 MB/s Changes I did are: On oss - lctl set_param obdfilter.lfsbv-*.brw_size=16 On clients - unmounted and remounted - lctl set_param osc.lfsbv-OST*.max_pages_per_rpc=4096 (got auto-updated after re-mount) - lctl set_param osc.*.max_rpcs_in_flight=64 (Had to manually increase this to 64, since after re-mount, it was auto-set to 8, but read/write performance was poor) - lctl set_param osc.*.max_dirty_mb=2040. (setting the value to 2048 was failing with : Numerical result out of range error. Previously it was set to 2000 when I got good performance. My other settings: - lnetctl net add --net tcp1 --if $interface –peer-timeout 180 –peer-credits 128 –credits 1024 - echo "options ksocklnd nscheds=10 sock_timeout=100 credits=2560 peer_credits=63 enable_irq_affinity=0" > /etc/modprobe.d/ksocklnd.conf - lfs setstripe -c 1 -S 1M /mnt/mdt_bv/test1 ___ lustre-discuss mailing list lustre-discuss@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
Re: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
With that kind of degradation performance on read I would immediately think on llite’s max_read_ahead parameters on the client. Specifically these 2: max_read_ahead_mb: total amount of MB allocated for read ahead, usually quite low for bandwidth benchmarking purposes and when there’re several files per client max_read_ahead_per_file_mb: the default is quite low for 16MB RPCs (only a few RPCs per file) You probably need to check the effect increasing both of them. Regards, Diego From: lustre-discuss on behalf of Pinkesh Valdria Date: Tuesday, 10 December 2019 at 09:40 To: "lustre-discuss@lists.lustre.org" Subject: [lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC) I was expecting better or same read performance with Large Bulk IO (16MB RPC), but I see degradation in performance. Do I need to tune any other parameter to benefit from Large Bulk IO? Appreciate if I can get any pointers to troubleshoot further. Throughput before - Read: 2563 MB/s - Write: 2585 MB/s Throughput after - Read: 1527 MB/s. (down by ~1025) - Write: 2859 MB/s Changes I did are: On oss - lctl set_param obdfilter.lfsbv-*.brw_size=16 On clients - unmounted and remounted - lctl set_param osc.lfsbv-OST*.max_pages_per_rpc=4096 (got auto-updated after re-mount) - lctl set_param osc.*.max_rpcs_in_flight=64 (Had to manually increase this to 64, since after re-mount, it was auto-set to 8, but read/write performance was poor) - lctl set_param osc.*.max_dirty_mb=2040. (setting the value to 2048 was failing with : Numerical result out of range error. Previously it was set to 2000 when I got good performance. My other settings: - lnetctl net add --net tcp1 --if $interface –peer-timeout 180 –peer-credits 128 –credits 1024 - echo "options ksocklnd nscheds=10 sock_timeout=100 credits=2560 peer_credits=63 enable_irq_affinity=0" > /etc/modprobe.d/ksocklnd.conf - lfs setstripe -c 1 -S 1M /mnt/mdt_bv/test1 ___ lustre-discuss mailing list lustre-discuss@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
[lustre-discuss] Degraded read performance with Large Bulk IO (16MB RPC)
I was expecting better or same read performance with Large Bulk IO (16MB RPC), but I see degradation in performance. Do I need to tune any other parameter to benefit from Large Bulk IO? Appreciate if I can get any pointers to troubleshoot further. Throughput before Read: 2563 MB/s Write: 2585 MB/s Throughput after Read: 1527 MB/s. (down by ~1025) Write: 2859 MB/s Changes I did are: On oss lctl set_param obdfilter.lfsbv-*.brw_size=16 On clients unmounted and remounted lctl set_param osc.lfsbv-OST*.max_pages_per_rpc=4096 (got auto-updated after re-mount) lctl set_param osc.*.max_rpcs_in_flight=64 (Had to manually increase this to 64, since after re-mount, it was auto-set to 8, but read/write performance was poor) lctl set_param osc.*.max_dirty_mb=2040. (setting the value to 2048 was failing with : Numerical result out of range error. Previously it was set to 2000 when I got good performance. My other settings: lnetctl net add --net tcp1 --if $interface –peer-timeout 180 –peer-credits 128 –credits 1024 echo "options ksocklnd nscheds=10 sock_timeout=100 credits=2560 peer_credits=63 enable_irq_affinity=0" > /etc/modprobe.d/ksocklnd.conf lfs setstripe -c 1 -S 1M /mnt/mdt_bv/test1 ___ lustre-discuss mailing list lustre-discuss@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
