>>> On Tue, 14 Feb 2012 14:55:03 -0500, "Charland, Denis" >>> <[email protected]> said:
> [ ... ] On a Lustre 1.8.7 client, I untared a tarfile of a > directory containing about 225,000 files (6.4GB). Writing lots of small files is not the most appropriate. Also, it may make a big difference where the 'tar' file was stored, and in how many directories the files ended up. > [ ... ] it took about 4 minutes to untar the tarfile when > running the kernel without SD_IOSTATS compared to about 16 > minutes when running the kernel with SD_IOSTATS. [ ... ] On the client or the OSS or MDS? Anyhow stats collection in itself should not make a difference. There may something else involved. For example logging volume, which is known to make a significant difference. Perhaps also whether barriers (or 'sync') are enabled, which may conceivably remotely related to 'SD_IOSTATS'. Possibly you may have a stats collector program that results in a higher load on the MDS if 'SD_IOSTATS' is enabled. But looking at your numbers, in the faster case you were able to commit ~950 inodes/s and 26 MB/s, and even with Lustre not being the best for small files, that's not so good. Overall your report is vague and not very useful. Have you looked for example at 'vmstat' and 'iostat -dx' rates on the MDS/OSS hosts? Have you looked at the logs on both client and servers? Checked mount options, 'sync' and barriers? _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
