From da85c16561d7f397d8b6e4de08d59b8e920ccdab Mon Sep 17 00:00:00 2001 From: Jan Siwiec <jan.siwiec@vsb.cz> Date: Wed, 7 Jul 2021 08:31:13 +0000 Subject: [PATCH] Update storage.md --- docs.it4i/salomon/storage.md | 48 ++---------------------------------- 1 file changed, 2 insertions(+), 46 deletions(-) diff --git a/docs.it4i/salomon/storage.md b/docs.it4i/salomon/storage.md index e6356264f..421a23b9c 100644 --- a/docs.it4i/salomon/storage.md +++ b/docs.it4i/salomon/storage.md @@ -261,52 +261,7 @@ It is not recommended to allocate large amount of memory and use large amount of ### Global RAM Disk The Global RAM disk spans the local RAM disks of all the nodes within a single job. - - - -The Global RAM disk deploys -BeeGFS On Demand parallel filesystem, using local RAM disks as a storage backend. - -The Global RAM disk is mounted at /mnt/global_ramdisk. - -!!! note - The global RAM disk is on-demand. It has to be activated by **global_ramdisk=true** in the qsub command. - -```console -$ qsub -q qprod -l select=4,global_ramdisk=true ./jobscript -``` - -This command would submit 4 node job in qprod queue, once running a 440GB RAM disk shared across the 4 nodes will be created. -The RAM disk will be accessible at /mnt/global_ramdisk, files written to this RAM disk will be visible on all 4 nodes. - -The file system is private to a job and shared among the nodes, created when the job starts and deleted at the job end. - -!!! note - The Global RAM disk will be deleted immediately after the calculation end. Users should take care to save the output data from within the jobscript. - -The files on the Global RAM disk will be equally striped across all the nodes, using 512k stripe size. -Check the Global RAM disk status: - -```console -$ beegfs-df -p /mnt/global_ramdisk -$ beegfs-ctl --mount=/mnt/global_ramdisk --getentryinfo /mnt/global_ramdisk -``` - -Use Global RAM disk in case you need very large RAM disk space. The Global RAM disk allows for high performance sharing of data among compute nodes -within a job. - -!!! warning - Be very careful, use of Global RAM disk file system is at the expense of operational memory. - -| Global RAM disk | | -| ------------------ | --------------------------------------------------------------------------| -| Mountpoint | /mnt/global_ramdisk | -| Accesspoint | /mnt/global_ramdisk | -| Capacity | (N*110)GB | -| Throughput | 3*(N+1)GB/s, 2GB/s single POSIX thread | -| User quota | none | - -N = number of compute nodes in the job. +For more information, see the [Job Features][12] section. ## Summary @@ -382,6 +337,7 @@ N = number of compute nodes in the job. [9]: #shared-workspaces [10]: ../general/obtaining-login-credentials/obtaining-login-credentials.md [11]: ../storage/standard-file-acl.md +[12]: ../job-features.md#global-ram-disk [c]: https://access.redhat.com/documentation/en-US/Red_Hat_Storage/2.0/html/Administration_Guide/ch09s05.html [d]: https://support.it4i.cz/rt -- GitLab