Hello Jan Just,

Luckily (for us) there are a few mistakes in your lines about StoRM. The checksum behaviour is nevertheless exactly what I also notice. I will have to report this to the developers. Here are some corrections for the other parts:

- First a link to the StoRM homepage with up-to-date information: http://storm.forge.cnaf.infn.it/home - SRMv2.2 compliant - Latest release 1.4.0 (15/05/2009) - With respect to ACLs I'm not completely sure yet what the precise capabilities are. If missing it should be fairly straightforward to implement these because StoRM already makes use of extended ACLs on the file system, and these could be made more fine grained. - The plain GridFTP is the VDT 1.6.1 version also used in gLite 3.1. - Checksumming support is currently being improved. Adler32 seems to be optional according to the release notes, but I will have to look into this.

Best wishes,

Fokke

Jan Just Keijser wrote:

hi all,

here's a quick rundown of checksumming in GFAL and the various storage systems used throughout biggrid:

dCache

• source code not available
• support (HEP-preferred?) ADLER32 checksums only
• checksum is calculated when the file is uploaded and stored in a

database; this means that it is not possible to verify whether the file on disk/tape actually matches the checksum. A dCache operator can trigger a command to re-calculate the checksum

DPM

• supports ADLER32, MD5 and CRC32 checksums
• checksum is calculated if not present in the DPM namespace and then

stored there; this means that the first time you request a checksum it can take a while (and can put quite some stress on the DPM worker nodes)

• uses a plain gridftp server with a DPM plugin to calculate the

ADLER32 and CRC32 checksums.

• I browsed through the sources to check/find out some of this

StoRM

• does not seem to support checksums in a consistent manner at all
• uses a plain gridftp server which only supports MD5 checksums yet

lcg-cr .... --checksum --checksum-type md5 always fails

• it is possible to calculate the checksum of a file on the storm

gridftp server but it is not stored anywhere for fast access: this makes it ideal for a Denial-of-Server-Storage attack :)

• is actually only SRMv2.1 compliant
• also does not support ACLs/permissions
• no new version has been released since 2007
• I browsed through the sources to check/find out some of this

Hopefully I've missed a few things on the storm front, otherwise things don't look too good ...

share and enjoy,

JJK _______________________________________________ Ct-grid mailing list Ct-grid@nikhef.nl https://mailman.nikhef.nl/cgi-bin/listinfo/ct-grid