The effective limit of the base name for a volume group is still 22 until AuriStor can finish writing the code necessary to permit Cell Administrators to configure and advertise a larger limit. The name must leave room for appending “.readonly” and “.backup” extensions plus store the trailing NUL.
A bit of background:
The maximum volume name length is specified independently for each service wire protocol and on-disk/database format. The values in IBM AFS 3.6/OpenAFS range from 32 to 65 depending upon the service and the client. The location service (vlserver) has supported base names up to 55 characters (65 with “.readonly” and trailing NUL) since 1988. However, there are other services and wire protocols that also transmit and store volume names:
volume manager server (volserver): IBM/OpenAFS limit 32 (including trailing NUL)
backup database: limit 32 (incl NUL)
backup tape controller: limit 64 (incl NUL)
cache manager: no limit
vos or equivalent administration tools: limit 32 (incl NUL)
vos and equivalent tools hard code the limit of 32 because there is no method by which to determine what the cell’s permitted maximum volume name length is.
AuriStor has raised many of the limits. Updated wire protocols now support names up to 512 characters (incl NUL). The on-disk format of the volserver also supports up to 512 characters. However, the location service database (VLDB) is still based upon the IBM/OpenAFS format for compatibility which includes the 65 character limit.
The backup database on-disk format is also the IBM/OpenAFS format with its 32 character limit (incl NUL).
In the next major release the intention is to provide a backward compatible extension to the VLDB format which will permit the location service to advertise support for up to 65 character names (incl NUL) or base names up to 55 characters. This will be enabled via a new vos command and RPC on the location service. Cell admins can enable the longer names provided that the in-use backup service does not hard code a smaller name length. Not only does the AFS Backup service have a limit of 32 but TiBS internally enforces that limit as well.
Volume names are case sensitive and are limited to the following characters.
VLLEGALCHARS ".ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
Prior to AuriStorFS v2021.05-63, there have been no restrictions on assigning a volume name which is a base-10 numeric value. For example “12345” or even “00003” or “-98765”. Volume names such as this are problematic because its impossible to lookup a volume by name if the name is a valid base-10 numeric value. The base-10 numeric string is converted to a 64-bit unsigned integer for comparison to the assigned volume ids. Beginning with v2021.05-63, the location service enforces the requirement that a numeric volume name must match the RW volume ID.