Re: [zfs-discuss] Odp: Is ZFS efficient for large collections of small files?
Hello Roch, Wednesday, August 22, 2007, 10:13:10 AM, you wrote: RP> £ukasz K writes: >> > Is ZFS efficient at handling huge populations of tiny-to-small files - >> > for example, 20 million TIFF images in a collection, each between 5 >> > and 500k in size? >> > >> > I am asking because I could have sworn that I read somewhere that it >> > isn't, but I can't find the reference. >> >> It depends, what type of I/O you will do. If only reads, there is no >> problem. Writting small files ( and removing ) will fragmentate pool >> and it will be a huge problem. >> You can set recordsize to 32k ( or 16k ) and it will help for some time. >> RP> Comparing recordsize of 16K with 128K. RP> Files in the range of [0,16K] : no difference. RP> Files in the range of [16K,128K] : more efficient to use 128K RP> Files in the range of [128K,500K] : more efficient to use 16K RP> In the [16K,128K] range the actual filesize is rounded up to RP> 16K with 16K recordsize and to the nearest 512B boundary RP> with 128K recordsize. This will be fairly catastrophic for RP> files slightly above 16K (rounded up to 32K vs 16K+512B). RP> In the [128K, 500K] range we're hurt by this RP> 5003563 use smaller "tail block" for last block of object RP> until it is fixed, then yes , files stored using 16K RP> records are rounded up more tightly. metadata probably RP> east parts of the gains. Roch, I guess Lukasz was talking about some problems we're seeing here which are partly caused by utilizing all 128KB slabs, so forcing file system to 16KB helps here (for CPU) - workaround. Sure, we're talking about lots and lots of files, really small. Perhaps someone could work with Lukasz and investigate it more closely. Lukasz posted so more detailed info not so long ago - unfortunately there was no feedback. -- Best regards, Robert Milkowski mailto:[EMAIL PROTECTED] http://milek.blogspot.com ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Odp: Is ZFS efficient for large collections of small files?
£ukasz K writes: > > Is ZFS efficient at handling huge populations of tiny-to-small files - > > for example, 20 million TIFF images in a collection, each between 5 > > and 500k in size? > > > > I am asking because I could have sworn that I read somewhere that it > > isn't, but I can't find the reference. > > It depends, what type of I/O you will do. If only reads, there is no > problem. Writting small files ( and removing ) will fragmentate pool > and it will be a huge problem. > You can set recordsize to 32k ( or 16k ) and it will help for some time. > Comparing recordsize of 16K with 128K. Files in the range of [0,16K] : no difference. Files in the range of [16K,128K] : more efficient to use 128K Files in the range of [128K,500K] : more efficient to use 16K In the [16K,128K] range the actual filesize is rounded up to 16K with 16K recordsize and to the nearest 512B boundary with 128K recordsize. This will be fairly catastrophic for files slightly above 16K (rounded up to 32K vs 16K+512B). In the [128K, 500K] range we're hurt by this 5003563 use smaller "tail block" for last block of object until it is fixed, then yes , files stored using 16K records are rounded up more tightly. metadata probably east parts of the gains. -r > Lukas > > > CLUBNETIC SUMMER PARTY 2007 > House, club, electro. Najlepsza kompilacja na letnie imprezy! > http://klik.wp.pl/?adr=http%3A%2F%2Fadv.reklama.wp.pl%2Fas%2Fclubnetic.html&sid=1266 > > > ___ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Odp: Is ZFS efficient for large collections of small files?
£ukasz K writes: > > Is ZFS efficient at handling huge populations of tiny-to-small files - > > for example, 20 million TIFF images in a collection, each between 5 > > and 500k in size? > > > > I am asking because I could have sworn that I read somewhere that it > > isn't, but I can't find the reference. > > It depends, what type of I/O you will do. If only reads, there is no > problem. Writting small files ( and removing ) will fragmentate pool > and it will be a huge problem. > You can set recordsize to 32k ( or 16k ) and it will help for some time. > Comparing recordsize of 16K with 128K. Files in the range of [0,16K] : no difference. Files in the range of [16K,128K] : more efficient to use 128K Files in the range of [128K,500K] : more efficient to use 16K In the [16K,128K] range the actual filesize is rounded up to 16K with 16K recordsize and to the nearest 512B boundary with 128K recordsize. This will be fairly catastrophic for files slightly above 16K (rounded up to 32K vs 16K+512B). In the [128K, 500K] range we're hurt by this 5003563 use smaller "tail block" for last block of object until it is fixed, then yes , files stored using 16K records are rounded up more tightly. metadata probably east parts of the gains. -r > Lukas > > > CLUBNETIC SUMMER PARTY 2007 > House, club, electro. Najlepsza kompilacja na letnie imprezy! > http://klik.wp.pl/?adr=http%3A%2F%2Fadv.reklama.wp.pl%2Fas%2Fclubnetic.html&sid=1266 > > > ___ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss